JP4817263B2 - Image processing apparatus, image processing method, and program - Google Patents

Description

  The present invention relates to an image processing device, an image processing method, and a program. The present invention particularly relates to an image processing apparatus and an image processing method for encoding an image, and a program for the image processing apparatus.

For the purpose of reducing the amount of data of a compression-coded moving image, a technique for converting an I picture, which is an intra-coded moving image constituent image, into a P picture is known (for example, Patent Documents 1 and 2). reference.).
JP 2001-145112 A JP-A-10-66092

  However, according to the technique described in Patent Document 1, since the macroblock type of the I picture is merely converted into the intra macroblock of the P picture, the data amount cannot be reduced. Also, according to the technique described in Patent Document 2, when there is no scene change, the picture type is not changed, so that the data amount of moving images cannot be effectively reduced.

  In order to solve the above-described problem, in the first embodiment of the present invention, an image processing apparatus, a moving image acquisition unit that acquires a moving image including a moving image constituent image having an intra-coded region, and intra coding A change amount detection unit that detects a change amount of an image between a moving image constituent image having the specified region and another moving image constituent image, and an intra code of the moving image constituent image when the change amount is smaller than a predetermined value A recompression unit that compresses the image of the converted area by inter-coding that refers to another moving image constituent image.

  The image processing apparatus further includes a feature region detection unit that detects a feature region in a plurality of movie composition images included in the movie, and the change amount detection unit includes a feature region having an intra-coded region in the movie composition image and another movie composition image. The amount of change between the feature region is detected, and the recompression unit, when the amount of change is smaller than a predetermined value, displays an image of the feature region having an intra-coded region in another moving image constituent image. You may compress by the inter encoding which refers to a characteristic area.

  The moving image acquisition unit acquires a moving image including an I picture that is a moving image constituent image having an intra-coded region, and the change amount detecting unit includes a feature region in the moving image constituent image that is an I picture and another moving image constituent image. The amount of change between the feature region is detected, and when the amount of change is smaller than a predetermined value, the recompression unit selects a moving picture constituent image that is an I picture as a P picture that references another moving picture constituent image or You may compress by converting into a B picture.

  The change amount detection unit detects a change amount between a feature region in a moving image constituent image that is an I picture and a feature region in another moving image constituent image that is another I picture. When the value is smaller than the predetermined value, the moving picture constituent image that is an I picture may be compressed by converting it into a P picture or a B picture that refers to another moving picture constituent image that is another I picture.

  The recompressing unit is intra-coded based on the image difference between the feature region having the intra-coded region and the feature region in another moving image constituent image when the change amount is smaller than a predetermined value. You may compress the image of the characteristic area | region which has an area | region.

  The recompressing unit is configured such that the difference between the position of the feature area having the intra-coded area and the position of the feature area having the intra-coded area in the feature area of the other moving image constituent image that takes the difference. The image of the feature region having the intra-coded region may be compressed based on the difference in the image between the feature region having the position difference and the intra-coded region and the difference target region.

  The recompressing unit decompresses the feature region having the intra-coded region and the feature region in the other moving image constituent image, and the pixel information of the feature region having the intra-coded region and the feature in the other moving image forming image. The image of the feature region having the intra-coded region is compressed by the difference between the image expansion unit that acquires the pixel information of the region and the image generated based on the pixel information obtained by the image expansion unit. A differential recompression unit.

  The moving image acquisition unit acquires a moving image including an inter-coded moving image constituent image between a moving image forming image having an intra-coded region and another moving image forming image, and the change amount detecting unit performs inter encoding The change amount may be detected based on the encoded information included in the moving image constituent image.

  The change amount detection unit may detect the change amount based on at least one of the difference information and the motion vector of the image included in the inter-coded moving image constituent image.

  The change amount detection unit compresses the moving image constituent image having the intra-coded region by comparing it with other moving image constituent images, and the moving image constituent image having the intra-coded region is compressed at a higher compression rate. The smaller the amount of change may be detected.

  According to the second aspect of the present invention, there is provided a video processing method for acquiring a moving image including a moving image forming image having an intra-coded region, and a moving image forming image having an intra-coded region. A change amount detection stage for detecting a change amount of an image between the image and another moving image constituent image, and when the amount of change is smaller than a predetermined value, an image of an intra-coded region of the moving image constituent image, A re-compression step of compressing by inter coding referring to another moving image constituent image.

  According to a third aspect of the present invention, there is provided an image processing device program for processing an image, the image processing device program for processing an image, the image processing device having an intra-coded region. A moving image acquisition unit that acquires a moving image including a moving image configuration image, a change amount detection unit that detects a change amount of an image between a moving image configuration image having an intra-coded region and another moving image configuration image, When it is smaller than the predetermined value, it functions as a recompression unit that compresses the intra-coded region image of the moving image constituent image by inter encoding that refers to another moving image constituent image.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows an example of an image processing system 10 according to an embodiment. An object of the image processing system 10 is to reduce the amount of image data while maintaining a high quality image of a characteristic subject.

  The image processing system 10 includes a plurality of imaging devices 100a-c (hereinafter collectively referred to as imaging devices 100) that image the monitoring target space 150, and a plurality of image processing devices 120a-c (hereinafter referred to as image processing devices) that process images. 120), an image processing device 170, a communication network 110, and a plurality of display devices 180a-c (hereinafter collectively referred to as display device 180).

  The image processing device 120a is connected to the imaging device 100a. Further, the image processing device 120b is connected to the imaging device 100b. Further, the image processing device 120c is connected to the imaging device 100c. Note that the image processing device 170 and the display device 180 are provided in a space 160 different from the monitoring target space 150.

  Hereinafter, operations of the imaging device 100a, the image processing device 120a, the image processing device 170, and the display device 180a will be described. The imaging apparatus 100a MPEG-encodes a captured moving image obtained by imaging the monitoring target space 150, generates captured moving image data, and outputs the captured moving image data to the image processing apparatus 120a to which the imaging apparatus 100a is connected.

  The image processing device 120a acquires the captured moving image data generated by the imaging device 100a. The image processing device 120 decodes the captured moving image data acquired from the imaging device 100 to generate a captured moving image, and a plurality of features having different types of features such as a person 130 and a moving object 140 such as a vehicle from the generated captured moving image. Detect areas. Then, the image processing device 120a generates a plurality of feature area moving images by generating a moving image in which the characteristic region has a higher image quality than the other regions for each type of feature from the captured moving image. In addition, the image processing apparatus 120a generates a background area moving image that is a moving image of a background area other than the characteristic area and has a lower image quality than the characteristic area moving image.

  Then, the image processing device 120a generates a plurality of feature region moving image data and background region moving image data by encoding the generated plurality of feature region moving images and background region moving images, respectively. At the same time, the image processing device 120a associates a plurality of characteristic area moving image data and background region moving image data obtained by encoding with each other and transmits them to the image processing device 170 through the communication network 110.

  The image processing device 170 acquires a plurality of feature region moving images and a background region moving image by decoding the associated plurality of feature region moving image data and background region moving image data received from the image processing device 120a, respectively. Then, the image processing apparatus 170 generates a single combined moving image by combining the plurality of feature region moving images and the background region moving image, and supplies the generated combined moving image to the display device 180a. The display device 180a displays the moving image supplied from the image processing device 170.

  The functions and operations of the imaging device 100b and the imaging device 100c are the same as the functions and operations of the imaging device 100a, except that the imaging moving image data is provided to the image processing device 120b and the image processing device 120c, respectively. The description is omitted. The functions and operations of the image processing device 120b and the image processing device 120c are the same as the functions and operations of the image processing device 120a, except that the captured moving image data is acquired from the imaging device 100b and the imaging device 100c, respectively. Good. Therefore, the description is omitted. In addition, the image processing device 170 generates one moving image from the plurality of associated feature area moving image data and background area moving image data received from the imaging device 100b and the imaging device 100c, respectively, and displays each of the display devices 180b and It supplies to the display apparatus 180c. In addition, the display device 180b and the display device 180c display each moving image supplied from the image processing device 170.

  When the image processing system 10 of the present embodiment is actually applied as a monitoring system, for example, there may be a case where a subject that is characteristic as a monitoring target such as a person or a moving object can be left with high image quality. In addition, the amount of moving image data may be reduced.

  FIG. 2 shows an example of a block configuration of the image processing apparatus 120. The image processing apparatus 120 includes a compressed moving image acquisition unit 201, a compressed moving image decompression unit 202, a feature region detection unit 203, an image division unit 204, an image generation unit 205, a fixed value unit 210, a reduction unit 220, an encoding unit 230, The recompression unit 270, the association processing unit 206, and the output unit 207 are included.

  Fixed value unit 210 includes a plurality of fixed value units 211a to 211c (hereinafter collectively referred to as fixed value unit 211). The reduction unit 220 includes a plurality of image quality reduction units 221a-d (hereinafter collectively referred to as image quality reduction units 221).

  The encoding unit 230 includes a background region moving image encoding unit 231a and a plurality of feature region moving image encoding units 231b-d (hereinafter collectively referred to as a feature region moving image encoding unit 231). The background area moving image encoding unit 231a and the feature area moving image encoding unit 231b-d may be collectively referred to as an encoding unit 231.

  The image quality reduction unit 221a and the background area moving image encoding unit 231a function as the compression unit 240a. Further, the image quality reduction unit 221b and the feature area moving image encoding unit 231b function as the compression unit 240b. Similarly, the image quality reduction unit 221c and the feature area moving image encoding unit 231c function as the compression unit 240c. The image quality reduction unit 221d and the feature area moving image encoding unit 231d function as the compression unit 240d. The plurality of compression units 240a-d are collectively referred to as the compression unit 240.

  The compressed moving image acquisition unit 201 acquires a compressed moving image. Specifically, the compressed moving image acquisition unit 201 acquires encoded captured moving image data generated by the imaging device 100. The compressed moving image decompression unit 202 restores the moving image acquired by the compressed moving image acquisition unit 201 and generates a plurality of moving image constituent images included in the moving image. Specifically, the compressed moving image decompression unit 202 decodes the captured moving image data acquired by the compressed moving image acquisition unit 201, and generates a plurality of moving image constituent images included in the moving image. The moving image composition image includes a frame image and a field image.

  The feature region detection unit 203 detects a feature region from a plurality of moving image constituent images included in the moving image. Then, the image dividing unit 204 divides each of the plurality of moving image constituent images into a feature area and a background area.

  The image generation unit 205 generates a plurality of feature area compression moving images each including a plurality of feature area images by extracting feature area images from the plurality of moving image constituent images. Specifically, the image generation unit 205 reproduces a moving image to compress a plurality of feature region moving images and compress a plurality of feature region moving images and a background region moving image to compress a background region moving image. Generate a video.

  Then, the fixed value converting unit 211 converts the pixel values of regions other than the feature region image in the plurality of moving image constituent images included in the feature region compression moving image to a fixed value. For example, the fixed value unit 211 sets a pixel value of an area other than the feature area image to a predetermined value (for example, a luminance value of 0). Then, the compression unit 240 compresses a plurality of feature region compression images each including a plurality of moving image constituent images in which pixel values of regions other than the feature region image are fixed values with an intensity corresponding to each feature amount. . As described above, the compression unit 240 compresses each of the plurality of feature region compression moving images and the background region compression moving image with an intensity corresponding to each feature amount.

  As described above, the feature region detection unit 203 detects a feature region from the image. Then, the image dividing unit 204 divides the image into a feature region and a background region other than the feature region. Then, the compression unit 240 compresses the feature area image that is the image of the feature area and the background area image that is the image of the background area with different strengths. Then, the compression unit 240 compresses the feature area moving image including a plurality of characteristic area images and the background area moving image including a plurality of background area images with different strengths.

  Note that in the compression unit 240b, the compression unit 240c, and the compression unit 240d, it is determined in advance which type of feature area moving image should be compressed, and the compression unit 240b, the compression unit 240c, and the compression unit 240d are determined in advance. The feature region moving image of the specified feature type is compressed. Note that the compression strength in the case of compressing the feature region moving image is determined in advance for each of a plurality of feature types, and the compression unit 240b, the compression unit 240c, and the compression unit 240d are features of the predetermined feature types. The area moving image is compressed with a compression strength predetermined for the type of the feature. As described above, the compression unit 240 compresses a plurality of regions in parallel using the compressor provided for each image region divided by the image dividing unit 204.

  Note that the compression unit 240 may be implemented by a single compressor, and may sequentially compress a plurality of feature area videos and background area videos. In addition, the compression unit 240 is predetermined for each feature type and background of each region for each region obtained by dividing the captured moving image decoded by the compressed moving image decompression unit 202 by the image dividing unit 204. One video data may be generated by compressing at a compression rate.

  Note that the feature region detection unit 203 detects a plurality of feature regions having different types of features from a plurality of moving image constituent images included in a moving image that is an image. Then, the image dividing unit 204 divides the plurality of moving image constituent images into each of a plurality of feature areas and a background area other than the plurality of feature areas. Then, the compression unit 240 compresses the plurality of feature area moving images and the background area moving image with an intensity corresponding to each feature amount. The feature amount includes the type of subject, the size of the subject, the moving speed at which the moving object moves, and the size of the feature region.

  Specifically, the image quality reduction unit 221 compresses the plurality of feature region moving images and the background region moving image by reducing the image quality in accordance with the respective feature amounts, whereby the plurality of feature region moving image data and the background region are compressed. Generate video data. More specifically, the image quality reduction unit 221 compresses a plurality of feature region moving images and background region moving images by reducing the resolution or frame rate according to each feature amount. Then, the encoding unit 231 compresses the plurality of feature area moving images and the background area moving image by encoding using setting values corresponding to the respective feature amounts. For example, the encoding unit 231 compresses a plurality of feature area moving images and background area moving images by encoding them using an assigned code amount corresponding to each feature amount.

  The recompression unit 270 recompresses each of the plurality of feature area moving image data and background area moving image data generated by the encoding unit 231. Then, the association processing unit 206 associates each of the plurality of feature area moving image data and background area moving image data recompressed by the recompression unit 270 with, for example, tag information or the like. The output unit 207 sends the plurality of feature area moving image data and background area moving image data associated by the association processing unit 206 to the communication network 110.

  Note that the feature region detection unit 203 calculates a certainty factor indicating the degree of reliability when the feature amounts of the plurality of feature regions are specified for each of the plurality of feature regions. Then, the compression unit 240 compresses the plurality of feature area moving images with the strength corresponding to each feature amount and certainty factor. For example, the image quality reduction unit 221 compresses a plurality of feature area moving images by reducing the resolution or the frame rate in accordance with each feature amount and certainty factor. Then, the encoding unit 231 compresses the plurality of feature area moving images by encoding using a set value corresponding to each feature amount and certainty factor. For example, the compression unit 240 may compress a plurality of feature region moving images at a strength lower than the strength corresponding to each feature amount as the certainty factor is lower.

  FIG. 3 shows an example of a block configuration of the image processing apparatus 170. The image processing apparatus 170 includes a compressed moving image acquisition unit 301, an association analysis unit 302, a compressed moving image decompression unit 310, a moving image generation unit 303, and an output unit 304. The compressed moving image expansion unit 310 includes a plurality of compressed moving image expansion units 311a-d (hereinafter collectively referred to as a compressed moving image expansion unit 311).

  The compressed moving image acquisition unit 301 acquires a plurality of associated feature region moving image data and background region moving image data output from the output unit 207. The association analysis unit 302 analyzes, for example, attached tag information, and extracts a plurality of associated feature region movie data and background region movie data acquired by the compressed movie acquisition unit 301.

  The compressed moving image decompression unit 311 decodes the plurality of characteristic area moving image data and background area moving image data. Specifically, the compressed moving image decompression unit 311a decodes the background area moving image data. In addition, the compressed moving image decompression unit 311b-d decodes one feature region moving image out of the plurality of feature region moving image data, and acquires a plurality of feature region moving images and a background region moving image. Note that the compressed moving image decompression unit 311b-d is provided for each type of feature, and decodes any type of feature region moving image data.

  The moving image generation unit 303 synthesizes the moving image constituent images obtained by the compressed moving image expansion unit 311 decoding. Specifically, the moving image generation unit 303 converts the image of the feature area of the moving image constituent image included in each of the plurality of characteristic area moving images decoded by the compressed moving image extension unit 311b-d into the moving image constituent image included in the background area moving image. A superimposed moving image composition image is generated. The output unit 304 supplies a moving image including a plurality of moving image constituent images generated by the moving image generating unit 303 to the display device 180.

  Note that the compressed video decompression unit 310 of the present embodiment includes a plurality of compressed video decompression units 311 corresponding to the number of feature types, but in another form, one compressed video decompression unit included in the compressed video decompression unit 310. 311 may sequentially decode the background area moving image data and the plurality of characteristic area moving image data. In addition, when provided as one moving image data from the image processing device 120, one compressed moving image decompression unit 311 decodes the one moving image data, and the output unit 304 outputs the decoded moving image. May be.

  FIG. 4 shows another example of the block configuration of the image processing apparatus 120. The image processing apparatus 120 includes a compressed moving image acquisition unit 201, a compressed moving image decompression unit 202, a feature region detection unit 203, an input moving image image quality control unit 280, an image quality reduction unit 281, and an inter-layer difference compression unit 282a-d (hereinafter referred to as inter-layer difference). A re-compression unit 270, and an output unit 207.

  The compressed moving image acquisition unit 201 acquires a compressed moving image. Specifically, the compressed moving image acquisition unit 201 acquires encoded captured moving image data generated by the imaging device 100. The compressed moving image decompression unit 202 restores the moving image acquired by the compressed moving image acquisition unit 201 and generates a plurality of moving image constituent images included in the moving image.

  Specifically, the compressed moving image decompression unit 202 decodes the captured moving image data acquired by the compressed moving image acquisition unit 201, and generates a plurality of moving image constituent images included in the moving image. The moving image composition image includes a frame image and a field image. The moving image composition image is an example of the input image in the present invention.

  The feature region detection unit 203 detects a feature region from a plurality of moving image constituent images included in the moving image. The input moving image quality control unit 280 controls the image quality of the feature region and the image quality of the region other than the feature region in accordance with the feature amount of the feature region in each of the plurality of moving image constituent images generated by the compressed moving image decompression unit 202.

  The image quality reduction unit 281 generates a plurality of moving images having different predetermined image quality by reducing the image quality of the moving images. Then, the image quality reduction unit 281 provides the generated moving images with different image quality to the inter-layer difference compression unit 282. Specifically, the image quality reduction unit 281 generates moving images having different image quality by reducing the frame rate of moving images or by reducing the resolution of moving image constituent images included in the moving images. Then, the inter-layer difference compression unit 282 acquires a moving image having a predetermined image quality from the image quality reduction unit 281 and compresses the acquired moving image. Note that the inter-layer difference compression unit 282 compresses moving images having different image quality.

  The moving image constituent image included in the moving image supplied from the image quality reducing unit 281 to the inter-layer difference compressing unit 282a may be an example of a low quality image in the present invention. Further, the moving image constituent image included in the moving image supplied from the image quality reduction unit 281 to the inter-layer difference compression unit 282b-d may be an example of a feature region image in the present invention. In this case, the image quality reduction unit 281 and the input moving image quality control unit 280 function as an image generation unit in the present invention.

  Note that the inter-layer difference compression unit 282a acquires a moving image constituent image having a lower resolution than the moving image constituent image received by any of the inter-layer difference compression units 282b-d from the image quality reduction unit 281 and compresses it. Note that the inter-layer difference compression unit 282 acquires a moving image constituent image having a lower resolution from the image quality reduction unit 281 in order of the inter-layer difference compression unit 282b, the inter-layer difference compression unit 282c, and the inter-layer difference compression unit 282d. To do.

  The inter-layer difference compression unit 282b expands the moving image constituent image compressed by the inter-layer difference compression unit 282a, and the moving image constituent image obtained by the expansion is the same as the resolution of the moving image constituent image acquired from the image quality reduction unit 281. Enlarge to the resolution. Then, the inter-layer difference compression unit 282b compresses the difference image between the moving image constituent image obtained by the enlargement and the moving image constituent image acquired from the image quality reduction unit 281. Note that the inter-layer difference compression unit 282b generates and compresses a difference image that has a difference value in the feature region but does not have a difference value in a region other than the feature region.

  Further, the inter-layer difference compression unit 282c expands the moving image constituent image compressed by the inter-layer difference compressing unit 282b, and the resolution of the moving image constituent image obtained from the image quality reduction unit 281 is obtained by expanding the moving image constituent image. To the same resolution. Then, the inter-layer difference compression unit 282c compresses the difference image between the moving image constituent image obtained by the enlargement and the moving image constituent image acquired from the image quality reduction unit 281. The inter-layer difference compression unit 282c has a difference value in at least a part of the plurality of feature areas according to the feature amount of the feature area, but in the area other than the at least some of the feature areas. A difference image having no difference value is generated and compressed.

  In addition, the inter-layer difference compression unit 282d expands the moving image constituent image compressed by the inter-layer difference compression unit 282c. Then, the hierarchical difference compression unit 282d expands the moving image constituent image obtained by the decompression to the same resolution as the resolution of the moving image constituent image acquired from the input moving image quality control unit 280. Then, the inter-layer difference compression unit 282d compresses a difference image between the enlarged moving image constituent image and the moving image constituent image acquired from the input moving image quality control unit 280. Note that the inter-layer difference compression unit 282d has a difference value in at least a part of the plurality of feature areas according to the feature amount of the feature area, but in the area other than the at least some of the feature areas. A difference image having no difference value is generated and compressed.

  In this way, the inter-layer difference compression unit 282b-d is between the moving image constituent image received from the input moving image quality control unit 280 or the image quality reducing unit 281 and the moving image constituent image obtained by enlarging the lower moving image constituent image. The difference image obtained by taking the difference is compressed. Then, the recompression unit 270 recompresses each of the moving images obtained by the compression of each of the inter-layer difference compression units 282. Further, the output unit 207 multiplexes and outputs each moving image recompressed by the recompression unit 270. Specifically, the output unit 207 transmits the moving image recompressed by the recompression unit 270 to the image processing apparatus 170 after the inter-layer difference compression unit 282 compresses. In this way, the image processing apparatus 120 can provide a moving image that is scalable and encoded according to the feature amount of the feature region.

  FIG. 5 shows an example of a block configuration of the inter-tier difference compression units 282a and b. The inter-layer difference compression unit 282a includes a motion analysis unit 285a, a motion encoding unit 286a, a difference processing unit 287a, and an encoding unit 288a. The motion analysis unit 285a includes a difference target area determination unit 294a and a position difference information generation unit 295a. The difference processing unit 287a includes a difference pixel image generation unit 296a, a spatial frequency domain conversion unit 297a, and a quantization unit 298a.

  The inter-layer difference compression unit 282b includes a motion analysis unit 285b, a motion encoding unit 286b, a difference processing unit 287b, an image enlargement unit 293b, an image decoding unit 292b, a pixel value changing unit 291b, and an encoding unit 288b. The motion analysis unit 285b includes a difference target area determination unit 294b and a position difference information generation unit 295b. The difference processing unit 287b includes a difference pixel image generation unit 296b, a spatial frequency domain conversion unit 297b, a quantization unit 298b, and a frequency domain image quality conversion unit 299b. Note that the inter-layer difference compression unit 282c and the inter-layer difference compression unit 282d have substantially the same constituent elements as the inter-layer difference compression unit 282b, and a description thereof will be omitted.

  The function and operation of each component of the inter-layer difference compression unit 282a will be described below. The motion analysis unit 285a analyzes the motion over the plurality of moving image constituent images based on the image contents of the plurality of moving image constituent images received from the image quality reduction unit 281 to compress the moving image constituent image based on the motion. To decide.

  Specifically, the difference target area determination unit 294a becomes a difference target in the case where a moving picture constituent image is compressed by a difference from another moving picture constituent image based on the pixel values of partial areas that span a plurality of moving picture constituent images. A partial area in another moving image constituent image is determined. The difference target area determination unit 294a supplies pixel information of the compression target partial area and pixel information of the difference target partial area to the difference processing unit 287a.

  In addition, the position difference information generation unit 295a generates position difference information indicating a position difference between the partial area to be compressed by the difference and the partial area to be the difference target. Specifically, the position difference information generation unit 295a generates a motion vector used for motion compensation. Then, the position difference information generation unit 295a supplies the generated position difference information to the motion encoding unit 286a.

  The motion encoding unit 286a encodes the position difference information supplied from the position difference information generation unit 295a and supplies the encoded information to the recompression unit 270. For example, the motion encoding unit 286 encodes the difference between the position difference information in the adjacent partial areas and supplies the encoded difference to the recompression unit 270.

  The difference processing unit 287a compresses the image of the partial area to be compressed based on the difference between the pixel information of the partial area to be compressed and the pixel information of the partial area to be difference received from the motion analysis unit 285a. Specifically, the difference pixel image generation unit 296a generates a difference pixel image based on the difference between the pixel information of the compression target partial area and the pixel information of the difference target partial area.

  Then, the spatial frequency domain conversion unit 297a converts the difference pixel image into the partial area c into the spatial frequency domain. Specifically, the spatial frequency domain conversion unit 297a converts each partial area in the difference pixel image into a spatial frequency domain by discrete cosine transform (DCT). The spatial frequency domain transform unit 297a may transform the difference pixel image into a spatial frequency domain for each partial region by various frequency transforms such as Hadamard transform or wavelet transform.

  When the motion analysis unit 285a determines that the compression is not performed due to a difference from another partial region of the moving image constituent image, the difference processing unit 287a converts the pixel information of the partial region to be compressed into the spatial frequency domain conversion unit. 297a. The spatial frequency domain conversion unit 297a converts the pixel information into a spatial frequency domain for each partial area as described above.

  The quantization unit 298a quantizes the transform coefficient obtained by the spatial frequency domain transform unit 297a transforming into the spatial frequency domain. Then, the encoding unit 288a compresses the transform coefficient quantized by the quantization unit 298a by encoding. For example, the encoding unit 288 encodes the transform coefficient quantized by the quantization unit 298a by entropy coding such as Huffman coding or arithmetic coding. Then, the encoding unit 288a supplies the moving image obtained by encoding to the recompression unit 270.

  Hereinafter, functions and operations of each component included in the inter-layer difference compression unit 282b will be described. Among the components included in the inter-layer difference compression unit 282b, the components denoted by the same reference numerals as those included in the inter-layer difference compression unit 282a are similar in function to the components included in the inter-layer difference compression unit 282a and Since it operates, description is abbreviate | omitted except the difference.

  Similar to the difference target region determination unit 294a, the difference target region determination unit 294b should take a difference from the compression target partial region included in the video component image for each of the plurality of video component images received from the image quality reduction unit 281. Then, a partial area in another moving image constituent image is specified. In this manner, the difference target area determination unit 294b determines a feature area partial area that is a partial area in a feature area image generated from another moving image constituent image, which should take a difference from the feature area image. Then, the difference target area determination unit 294b supplies pixel information of the compression target partial area and pixel information of the difference target partial area to the pixel value changing unit 291b.

  In addition, the image decoding unit 292b acquires a moving image constituent image from the encoding unit 288a, and acquires positional difference information from the motion encoding unit 286a. And the image decoding part 292b decodes the moving image structure image acquired from the encoding part 288a using the positional difference information acquired from the motion encoding part 286a. The image decoding unit 292b may acquire and decode the moving image constituent image quantized by the quantization unit 298a, or may acquire and decode the moving image constituent image encoded by the encoding unit 288a. The moving image constituent image obtained by decoding by the image decoding unit 292b may be an example of a low quality image in the present invention. In this case, the inter-layer difference compression unit 282a functions as an image generation unit that generates a low-quality image in the present invention.

  The image enlarging unit 293b generates an enlarged image by enlarging the moving image constituent image decoded by the image decoding unit 292b. Then, the pixel value changing unit 291b does not change the pixel value of the partial region including the characteristic region among the partial regions determined by the difference target region determining unit 294b, and changes the pixel value of the partial region not included in the characteristic region. The pixel value of the partial area in the enlarged image is replaced.

  As described above, the pixel value changing unit 291b generates a feature area image in which the pixel values of the area other than the feature area are replaced with the pixel values of the enlarged image from the input moving image constituent image. In the present invention, the pixel value changing unit 291b can function as an image generating unit that generates a feature region image in which pixel values of regions other than the feature region are replaced with pixel values of an enlarged image.

  The difference processing unit 287b receives, from the pixel value changing unit 291b, the feature region image to be compressed, the image information of the partial region that is the difference target of the partial region included in the feature region image, and the enlarged image. Then, the difference processing unit 287b encodes each of a plurality of partial regions included in the compression target feature region image using pixel information of the same feature region image (hereinafter referred to as intra coding). Whether encoding is performed using a difference from a partial area to be included in another moving image constituent image (hereinafter referred to as inter encoding), or encoding is performed using a difference from an enlarged image (hereinafter referred to as a hierarchy). Called inter compression). At this time, the difference processing unit 287b preferentially selects an encoding method with a smaller code amount after encoding. Since inter-layer coding is selected because pixel values are replaced so as not to have a difference in a region other than the feature region, the case where inter-layer coding is selected will be described first. A case where intra coding is selected will also be described.

  When the inter-layer coding is selected, the difference pixel image generation unit 296b generates a difference pixel image indicating a difference in pixel values between the feature region image and the enlarged image. Specifically, the difference pixel image generation unit 296b generates a difference pixel image based on the difference between the feature region image in which the pixel values of the regions other than the feature region are replaced and the enlarged image. In the feature region image, since the pixel values of the regions other than the feature region are replaced with the pixel values of the enlarged image, the difference pixel image generation unit 296b performs a difference between the feature region image and the enlarged image in the feature region. A difference pixel image having a difference value of pixel values and not having a difference value of pixel values in an area other than the feature area can be generated.

  When inter coding is selected, the difference pixel image generation unit 296b generates a feature region image generated by the pixel value change unit 291b and a feature region image generated by the pixel value change unit 291b from another moving image configuration image. The difference between is taken. Specifically, the difference pixel image generation unit 296b obtains a difference between the partial region image included in the feature region and the difference target partial region image determined by the difference target region determination unit 294b for the partial region. . In the feature region image, since the pixel values of the region other than the feature region are replaced with the pixel values of the enlarged image, the difference pixel image generation unit 296b determines the difference target region determination unit 294b in the partial region included in the feature region. A difference pixel image having a difference value of the pixel value between the partial area and the partial area determined by the difference target area determination unit 294b in the area other than the feature area is generated. .

  When intra coding is selected, the difference pixel image generation unit 296b selects the partial region image included in each of the feature region images as the pixel value of the other region of the feature region image or the pixel of the same partial region. A difference pixel image is generated by taking a difference from the value.

  The spatial frequency domain conversion unit 297b converts the difference pixel image into a spatial frequency domain for each partial region. Specifically, the spatial frequency domain transform unit 297b converts the difference value indicated by the difference pixel image into a partial region by discrete cosine transform (DCT), Hadamard transform, wavelet transform, or the like, similar to the spatial frequency domain transform unit 297a. Every time, it converts to the spatial frequency domain. Similar to the quantization unit 298a, the quantization unit 298b quantizes the transform coefficient obtained by the spatial frequency domain transform unit 297b transforming into the spatial frequency domain.

  Then, the frequency domain image quality conversion unit 299b includes at least some partial regions including regions other than the feature region among the spatial frequency components for each partial region obtained by being converted into the spatial frequency region by the spatial frequency region conversion unit 297b. A feature region difference image or a feature region difference image is generated by reducing the data amount of the spatial frequency component. Specifically, the frequency domain image quality conversion unit 299b reduces the size of a conversion coefficient indicating a frequency component higher than a predetermined frequency. The frequency domain image quality conversion unit 299b may set the conversion coefficient indicating a frequency component higher than a predetermined frequency to zero.

  As described above, the difference processing unit 287b has a spatial frequency component in which the difference between the feature region image and the enlarged image in the feature region is converted into the spatial frequency region, and the spatial frequency component data in the region other than the feature region. A feature region difference image with a reduced amount is generated. Then, the encoding unit 288b encodes the feature region difference image generated by the difference processing unit 287b.

  In addition, as described above, the difference processing unit 287b generates a feature region difference image that indicates a difference image between the feature region image in the feature region image and the feature region image in the low-quality image. More specifically, the difference processing unit 287 generates a feature region difference image between the feature region image in the feature region image and the enlarged image of the feature region image in the low-quality image.

  In the above description, the pixel value changing unit 291b has at least a region other than the feature region in the difference pixel image (a region other than the feature region having a predetermined feature type and having a higher resolution than the feature region. In order to set the difference value to 0 in the region other than the feature region having the type of feature to have, the pixel value other than the feature region is replaced with the pixel value of the enlarged image. However, the difference value in the difference pixel image can be set to 0 by other methods.

  For example, the pixel value changing unit 291b converts a pixel value of a region other than the feature region of the moving image constituent image acquired from the image quality reduction unit 281 into a predetermined pixel value, and also has the same image region as the region other than the feature region in the enlarged image May be converted into the predetermined pixel value. Even in this case, the difference value of the region other than the feature region in the difference pixel image can be set to 0, and the information amount of the region other than the feature region can be substantially reduced.

  In this way, the pixel value changing unit 291b generates a feature region image in which the pixel values of the regions other than the feature region and the pixel values of the region other than the feature region in the enlarged image are replaced with predetermined values from the moving image constituent image. . Then, the difference pixel image generation unit 296 generates a difference pixel image based on the difference between the feature region image and the enlarged image in which the pixel values of the regions other than the feature region are replaced.

  Note that the pixel value changing unit 291b sends the pixel values of the region other than the feature region of the moving image constituent image acquired from the image quality reducing unit 281 to the lower-layer hierarchical difference compression unit 282 (for example, the inter-layer difference compression unit 282a). The provided moving image constituent image may be replaced with the pixel value of the same region in the enlarged image. Even in this case, the difference value in the difference pixel image can be made substantially zero, and the information amount of the area other than the feature area can be substantially reduced.

  Note that the position difference information generation unit 295b generates position difference information indicating the position difference of the partial area that is the difference target and is included in the area other than the feature area. Specifically, the positional difference information generation unit 295b indicates the positional difference between the partial region to be compressed by the difference and the differential target partial region that is the partial region that is the differential target, as in the positional difference information generation unit 295a. Generate position difference information. The position difference information includes a motion vector in motion compensation.

  The position difference information changing unit 290b changes the position difference information so that the position difference information indicates that a partial area included in an area other than the feature area is different from the partial area at the same position. Specifically, the position difference information changing unit 290b converts the position difference information in the partial area included in the area other than the feature area into information indicating that there is no position difference. Also, the position difference information changing unit 290b acquires the position difference information from the motion encoding unit 286a, and converts the position difference information in the partial area included in the area other than the feature area into information indicating that there is no position difference. . Specifically, the position difference information changing unit 290b sets the magnitude of the motion vector in an area other than the feature area to zero. Specifically, the position difference information changing unit 290b sets the size of the motion vector received from the position difference information generating unit 295b to 0 for the region other than the feature region, and also receives the motion vector received from the motion encoding unit 286a. Set the size of to 0.

  Then, the motion encoding unit 286b encodes the position difference information. Specifically, similarly to the motion encoding unit 286a, the motion encoding unit 286b encodes a difference between position difference information in adjacent partial regions. The position difference information encoded by the motion encoding unit 286b is supplied to the recompression unit 270.

  In the present embodiment, the position difference information changing unit 290 converts the position difference information of the region other than the feature region, but the position difference information changing unit 290b is encoded by the motion encoding unit 286b. Above, position difference information of regions other than the feature region may be converted. That is, the position difference information changing unit 290b changes the position difference information encoded by the motion encoding unit 286 to indicate that a difference is taken between the partial areas other than the feature areas and the partial areas at the same position. May be.

  Note that the encoding unit 288b may generate encoded data having no difference information in a region other than the feature region. Specifically, encoded data that does not have difference information of partial areas included in areas other than the characteristic areas may be generated. In addition, the motion encoding unit 286b may generate encoded data that does not have position difference information in a partial region included in a region other than the feature region. As described above, the encoding unit 288b and the motion encoding unit 286b indicate that the image content of the region other than the feature region is the same as the image content of the same region in the other moving image constituent images, and the difference information and the position difference information. The encoded data shown by not having is generated. For example, the encoding unit 288b and the motion encoding unit 286b indicate the type of the partial area indicating that the image content of the partial area included in the area other than the feature area is the same as the image content of the same area in the other moving image constituent images. May be generated.

  For example, the encoding unit 288b and the motion encoding unit 286b are encoded in the encoding mode indicating that the partial region included in the region other than the feature region is simple inter-frame prediction and has no transform coefficient. Encoded data including the type of the partial area indicating the partial area may be generated. For example, the type of the partial area may be a type corresponding to NonMC NotCoded in MPEG encoding. As described above, the encoding unit 288b and the motion encoding unit 286b generate encoded data having no information indicating that the magnitude of the motion vector and the difference information are 0, so that a moving image constituent image after encoding is generated. Can be further reduced. The inter-layer difference compression unit 282b selects a prediction mode capable of minimizing the rate / distortion cost based on the Lagrange's undetermined multiplier method when determining a prediction mode including the encoding mode. It's okay.

  Note that the inter-layer difference compression unit 282c and the inter-layer difference compression unit 282d have components having the same functions as the inter-layer difference compression unit 282b. In the following description, components having the same names as the inter-layer difference compression unit 282 included in the inter-layer difference compression unit 282c and the inter-layer difference compression unit 282d are denoted by the same reference numerals. Then, it is distinguished from which of the inter-layer difference compression units 282b-d the component included by the end (b, c, d) of the code.

  For example, the motion analysis unit 285c is one of the components included in the inter-layer difference compression unit 282c, and the motion analysis unit 285d is one of the components included in the inter-layer difference compression unit 282d. Note that in the following description, the constituent elements having no alphabetic character at the end of the reference numerals indicate the entire constituent elements having the reference numerals included in the inter-layer difference compression unit 282b-d. For example, the pixel value changing unit 291 indicates pixel value changing units 291b-d.

  The functions and operations of the inter-layer difference compression unit 282c and the inter-layer difference compression unit 282d and the functions and operations of the inter-layer difference compression unit 282b are obtained by processing moving images having different image quality from the image quality reduction unit 281. The position difference information changing units 290c and d and the image decoding units 292c and d obtain position difference information and moving image constituent images for the difference from the other inter-layer difference compressing units 282 that process moving images with lower image quality. The place to do is different.

  More specifically, the position difference information changing unit 290c acquires the position difference information from the motion encoding unit 286b, and converts the acquired position difference information. In addition, the image decoding unit 292c acquires the position difference information from the motion encoding unit 286b, acquires the moving image configuration image from the encoding unit 288b, and decodes the acquired moving image configuration image using the position difference information. . Also, the position difference information changing unit 290d acquires the position difference information from the motion encoding unit 286c, and converts the acquired position difference information. Further, the image decoding unit 292d acquires the position difference information from the motion encoding unit 286c, acquires the moving image constituent image from the encoding unit 288c, and decodes the acquired moving image constituent image using the position difference information. .

  Note that the feature region detection unit 203 detects a plurality of feature regions having different types of features from the input moving image composition image. In this case, the image quality reduction unit 281 generates one feature region image from the input image by reducing the resolution in the feature region having one feature type, and the feature in the feature region having another feature type. Another feature area image having a higher resolution than the area image is generated from the input image. The inter-layer difference compression unit 282b-c is prepared for each type of feature region, and at least in a feature region of a predetermined type, a feature region having a difference in resolution from a region other than the feature region Process the image.

  Specifically, the inter-layer difference compression unit 282b processes a low-resolution feature region image having the lowest resolution in a region including all feature regions. The inter-layer difference compression unit 282c processes a medium-resolution feature region image having a higher resolution than the low-resolution feature region image in a predetermined type of feature region. Then, the inter-layer difference compression unit 282d processes a high-resolution feature area image having a high resolution in another predetermined type of feature area.

  In this way, the difference processing unit 287 converts the difference between one feature region image and an enlarged image into a spatial frequency region in a feature region having one feature type and a feature region having another feature type. A feature region difference image is generated in which the amount of spatial frequency component data is reduced in regions other than the feature region having the spatial frequency component and having one feature type and the other feature type.

  As described above, the difference processing unit 287 has a spatial frequency component in which a difference between one feature area image and an enlarged image is converted into a spatial frequency domain in a feature area having one feature type. A feature region difference image in which the amount of spatial frequency component data is reduced in a region other than a feature region having a feature type is generated, and another feature region image and another feature region in a feature region having another feature type The difference between the image and the enlarged image of the feature area has a spatial frequency component converted to the spatial frequency domain, and the amount of spatial frequency component data is reduced in areas other than those with other feature types A difference image between feature areas is generated.

  The encoding unit 288 encodes the feature region difference image, the feature region difference image, and the low-quality image. Then, the recompression unit 270 includes the positional difference information encoded by the motion encoding units 286a-d and the moving image constituent image encoded by the encoding units 288a-d (for example, a low-quality image, a feature region difference image, And the difference image between feature regions) are recompressed. Further, the output unit 207 multiplexes and outputs the position difference information and the moving image constituent image recompressed by the recompression unit 270.

  As described above, the inter-layer difference compression unit 282a generates a moving image constituent image having a low image quality of the entire image region including the feature region, that is, a moving image constituent image having a low spatial frequency component of the input moving image constituent image. . Then, the inter-layer difference compression unit 282b generates a moving image composition image having a higher frequency component than the inter-layer difference compression unit 282a and having a lower frequency component than the inter-layer difference compression unit 282c. Then, the inter-layer difference compression unit 282b generates a moving image constituent image in which a difference value with respect to the moving image constituent image generated by the inter-layer difference compression unit 282a is reduced in a region other than the feature region.

  Similarly, the inter-layer difference compression unit 282c generates a moving image composition image having a higher frequency component than the inter-layer difference compression unit 282b and having a lower frequency component than the inter-layer difference compression unit 282d. . The inter-layer difference compression unit 282d generates a moving image constituent image having a higher frequency component than the inter-layer difference compression unit 282c. Then, the inter-layer difference compressing unit 282c and the inter-layer difference compressing unit 282d are the moving image constituent images in which the difference values with respect to the moving image constituent images generated by the inter-layer difference compressing units 282b and c are reduced in the regions other than the feature regions, respectively. Generate.

  In this way, each of the inter-layer difference compression units 282b-d processes a moving image having a higher image quality than the other regions for a feature region having a predetermined feature type, thereby improving the image quality according to the feature type. Can provide different videos to the outside. At this time, since the inter-layer difference compression unit 282b-d compresses by the difference with the low-quality moving image constituent image processed by the other inter-layer difference compression unit 282, it can be compressed efficiently.

  Note that the feature region detection unit 203 may calculate a certainty factor indicating the degree of reliability detected as the feature region for each of the plurality of feature regions when detecting the feature amounts of the plurality of feature regions. Then, the inter-layer difference compression unit 282b-d compresses the image of the feature region whose resolution is adjusted according to the feature amount and the certainty factor of each of the plurality of feature regions. For example, the image quality reduction unit 281 may adjust the resolution of each image of the plurality of feature regions in accordance with the feature amount and the certainty factor and supply the images to the inter-layer difference compression unit 282. For example, the image quality reduction unit 281 may set each image of the plurality of feature regions to a higher resolution than a predetermined resolution according to the feature amount as the certainty factor is lower.

  Note that the image processing device 120 encodes hierarchically by encoding image differences between a plurality of layers having different resolutions as described above. As is clear from this, a part of the compression method by the image processing apparatus 120 is H.264. It is clear that a compression scheme according to H.264 / SVC is included.

  The image processing apparatus 170 acquires a plurality of moving image constituent images that have been compressed by the inter-layer difference compression units 282a-d and then recompressed by the recompression unit 270. Then, the image processing device 170 decodes each of the acquired moving image constituent images. Then, the image processing apparatus 170 generates a single composite image by superimposing a plurality of moving image constituent images obtained by decoding. Then, the image processing device 170 supplies a moving image including the generated composite image as a moving image constituent image to the display device 180.

  FIG. 6 shows an example of a block configuration of the recompression unit 270. The recompression unit 270 includes a moving image acquisition unit 271, a change amount detection unit 272, and a recompression unit 273.

  The moving image acquisition unit 271 acquires a moving image including a moving image constituent image having an intra-coded region. For example, the moving image acquisition unit 271 acquires a moving image from the encoding unit 231 or the inter-layer difference compression unit 282. The moving image acquisition unit 271 may acquire a moving image including an I picture that is a moving image constituent image having an intra-coded region. For example, the moving image acquisition unit 271 may acquire an MPEG moving image including an I picture that is a moving image constituent image having an intra-coded region.

  Note that the moving image acquisition unit 271 may acquire a moving image other than an MPEG moving image including moving image forming images other than an I picture that is a moving image forming image having an intra-coded region. For example, the moving image acquisition unit 271 may acquire a moving image including a P picture or a B picture having an intra-coded macroblock. The moving image acquisition unit 271 may acquire a Motion JPEG moving image.

  Moreover, the moving image acquisition unit 271 may acquire a moving image including a moving image constituent image having an intra-coded region and an inter-coded moving image constituent image between other moving image constituent images. For example, the moving image acquisition unit 271 includes an I picture that is a moving image constituent image having an intra-coded area, and a B picture or a P picture that is an inter encoded moving image constituent image between other moving image constituent images. You may acquire the animation containing.

  The change amount detection unit 272 detects a change amount of an image between the moving image constituent image acquired by the moving image acquisition unit 271 and another moving image constituent image. For example, the change amount detection unit 272 detects a change amount of an image between a moving image constituent image having an intra-coded region and another moving image constituent image. Note that the change amount detection unit 272 may detect a change amount between a feature region having an intra-coded region in a moving image constituent image and a feature region in another moving image constituent image. Further, the change amount detection unit 272 may detect a change amount between a feature region in a moving image constituent image that is an I picture and a feature region in another moving image constituent image.

  Note that, when the moving image acquisition unit 271 acquires an inter-coded moving image constituent image, the change amount detection unit 272 is configured to change the amount of change based on the encoding information included in the inter-coded moving image constituent image. May be detected. For example, the change amount detection unit 272 acquires encoded information from a plurality of inter-coded moving image constituent images, and predicts the change amount by a linear interpolation process using the acquired encoded information. Note that the change amount detection unit 272 may detect the change amount based on at least one of the difference information and the motion vector of the image included in the inter-coded moving image constituent image.

  Note that the change amount detection unit 272 compares the moving image constituent image having the intra-coded region with another moving image constituent image to obtain a difference, thereby obtaining the moving image constituent image having the intra-coded region. You may compress. In this case, the change amount detection unit 272 detects the smaller change amount as the moving image constituent image having the intra-coded region is compressed at a higher compression rate.

  In addition, the change amount detection unit 272 decodes the moving image configuration image having the intra-coded region and other moving image configuration images up to pixel data, and then the moving image configuration image acquired by the moving image acquisition unit 271 and the other moving image configuration image You may detect the variation | change_quantity of the image between moving image structure images. In addition, the change amount detection unit 272 decodes the moving image configuration image having the intra-coded region and other moving image configuration images up to the DCT coefficient, and then adds the moving image configuration image acquired by the moving image acquisition unit 271 and the other moving image configuration image. You may detect the variation | change_quantity of the image between moving image structure images.

  When the amount of change detected by the change amount detector 272 is smaller than a predetermined value, the recompressing unit 273 refers to the image of the intra-coded region of the moving image constituent image with respect to another moving image constituent image. Compress by inter coding. At this time, the recompression unit 273 may compress the image of the intra-coded region of the moving image constituent image after decoding up to pixel data. Further, the recompression unit 273 may compress the image of the intra-coded region of the moving image constituent image after decoding it up to the DCT coefficient.

  Also, the recompression unit 273 displays an image of a feature region having an intra-coded region in another moving image configuration image when the change amount detected by the change amount detection unit 272 is smaller than a predetermined value. You may compress by the inter encoding which refers to a characteristic area. Further, the recompression unit 273, when the change amount detected by the change amount detection unit 272 is smaller than a predetermined value, converts the moving picture constituent image that is an I picture into a P picture that refers to another moving picture constituent image or You may compress by converting into a B picture.

  Also, the recompression unit 273 converts the moving image constituent image that is an I picture into another moving image configuration that is another I picture when the amount of change detected by the change amount detecting unit 272 is smaller than a predetermined value. You may compress by converting into the P picture or B picture which refers to an image. Further, the recompression unit 273, when the change amount detected by the change amount detection unit 272 is smaller than a predetermined value, a feature region having an intra-coded region and a feature region in another moving image constituent image The image of the feature region having an intra-coded region may be compressed by the image difference between the two. Note that the recompression unit 273 detects the feature region having the intra-coded region and the feature region in another moving image constituent image when the change amount detected by the change amount detection unit 272 is smaller than a predetermined value. The image of the feature region having an intra-coded region may be compressed on the assumption that there is no difference between the images. The recompressing unit 273 also determines the position of the difference target region in the feature region of another moving image constituent image that takes a difference from the feature region having the intra-coded region, and the position of the feature region having the intra-coded region. The image of the feature region having the intra-coded region may be compressed by the position difference between the image and the difference between the feature region having the intra-coded region and the difference target region. .

  In addition, the recompression unit 273 includes an image expansion unit 273a and a differential recompression unit 273b. The image decompression unit 273a decompresses the feature region having the intra-coded region and the feature region in the other moving image constituent image, and the pixel information of the feature region having the intra-coded region and the other moving image constituent image. Pixel information of the feature area is acquired. The difference recompression unit 273b compresses the image of the feature region having the intra-coded region based on the difference between the images generated based on the pixel information obtained by the image decompression unit 273a. The recompression unit outputs the recompressed image to the association processing unit 206 or the output unit 207.

  FIG. 7 shows an example of a method for compressing a moving image constituent image. The moving image 700 shown in the upper part shows an MPEG moving image before the recompression unit 270 performs image processing. The moving image 700 includes a GOP 710, a GOP 720, and a GOP 730. Each of GOP 710, GOP 720, and GOP 730 includes a plurality of moving image constituent images.

  Each of GOP 710, GOP 720, and GOP 730 includes one I frame that is an intra-coded moving image constituent image. For example, the GOP 710 includes a moving image composition image 711 that is an I frame. The GOP 720 includes a moving image composition image 721 that is an I frame. And GOP730 contains the moving image structure image 731 which is an I frame.

  On the other hand, a moving image 700 shown in the lower part shows an MPEG moving image after the recompression unit 270 performs image processing. The moving image 700 shown in the lower row is different from the moving image 700 shown in the upper portion in that the moving image composition image 721 is a P frame, and accordingly, GOPs 710 and 720 are combined into a single GOP GOP 715. To do.

  The recompression unit 270 decodes a part or all of the moving image 700 to pixel data or DCT coefficients, and then changes the image between the moving image composing images 711, 721, and 731 with the other moving image composing images. Detect the amount. At this time, the other moving image constituting image may be any of a P frame, a B frame, and an I frame. Further, the recompression unit 270 may detect a change amount between each of the moving image constituent images 711, 721, and 731 and a plurality of other moving image constituent images.

  Then, the recompression unit 270 determines whether or not the detected change amount is smaller than a predetermined value for each of the moving image constituent images 711, 721, and 731. Further, the recompression unit 270 inter-codes the moving image constituent image determined to be smaller than a predetermined value among the moving image constituent images 711, 721, and 731.

  For example, since the moving image constituent image 721 is determined to have a detected change amount smaller than a predetermined value, the recompression unit 270 converts the moving image constituent image 721 into a P frame. Thereby, the recompression unit 270 inter-codes the moving image constituent image 721. On the other hand, since it is determined that the detected change amount is larger than the predetermined value in the moving image constituent images 711 and 731, the recompression unit 270 does not inter-code the moving image constituent images 711 and 731.

  FIG. 8 shows an example of a method for detecting the amount of change in an image. The moving image 800 is an MPEG moving image before the recompression unit 270 performs image processing. The moving image 800 includes a plurality of continuous moving image constituent images. Among the plurality of moving image constituent images, the moving image constituent image 801a is an I frame that is an intra-coded moving image constituent image. This moving image constituent image 801a includes a feature region 802a that is a region including the subject 810.

  Of the plurality of moving image constituent images, the moving image constituent image 801b is an I frame that is an intra-coded moving image constituent image. The moving image constituent image 801 b includes a feature region 802 b that is a region including the subject 810. The area of the feature region 802b, the average value of the luminance of each pixel, and the average value of the color difference of each pixel are the same as those of the feature region 802a. Further, the position of the feature region 802b in the moving image composition image 801b is different from the position of the feature region 801a in the moving image composition image 801a.

  For the moving picture 800 configured in this way, the recompression unit 270 detects the amount of change in the image between the feature area 802a of the moving picture composition image 801a and the feature area 802b of the moving picture composition image 801b. For example, the recompression unit 270 detects the amount of change in the average value of the luminance of each pixel and the average value of the color difference of each pixel between the feature region 802a and the feature region 802b. At this time, the recompression unit 270 may decode the moving image configuration image 801a and the moving image configuration image 801b so that the luminance and color difference of each pixel in the feature region 802a and the feature region 802b can be obtained. In addition, the recompression unit 270 may predict the change amount from the encoded information included in the moving image constituent image located between the moving image constituent image 801a and the moving image constituent image 801b.

  Then, the recompression unit 270 determines whether or not the detected change amount is smaller than a predetermined value. If the recompression unit 270 determines that the detected amount of change is smaller than a predetermined value, the recompression unit 270 inter-codes the moving image constituent image 801a. At this time, the recompression unit 270 may inter-code only the feature region 802a in the moving image constituent image 801a. Further, the recompression unit 270 may inter-code the entire moving image constituent image 801a.

  As described above, the image processing apparatus 120 according to the present embodiment detects the conversion amount between the intra-coded moving image constituent image and another moving image constituent image, and the detected change amount is smaller than a predetermined value. In this case, the intra-coded moving image constituent image is inter-coded. Thereby, when the image processing apparatus 120 of the present embodiment is applied to an actual monitoring system, the amount of moving image data can be reduced more efficiently than a monitoring system that does not apply the image processing apparatus 120 of the present embodiment. May be possible.

  FIG. 9 shows an example of the hardware configuration of the image processing device 120 and the image processing device 170. The image processing device 120 and the image processing device 170 include a CPU peripheral unit, an input / output unit, and a legacy input / output unit. The CPU peripheral section includes a CPU 1505, a RAM 1520, a graphic controller 1575, and a display device 1580 that are connected to each other by a host controller 1582. The input / output unit includes a communication interface 1530, a hard disk drive 1540, and a CD-ROM drive 1560 that are connected to the host controller 1582 by the input / output controller 1584. The legacy input / output unit includes a ROM 1510, a flexible disk drive 1550, and an input / output chip 1570 connected to the input / output controller 1584.

  The host controller 1582 connects the RAM 1520, the CPU 1505 that accesses the RAM 1520 at a high transfer rate, and the graphic controller 1575. The CPU 1505 operates based on programs stored in the ROM 1510 and the RAM 1520 to control each unit. The graphic controller 1575 acquires image data generated by the CPU 1505 or the like on a frame buffer provided in the RAM 1520 and displays the image data on the display device 1580. Alternatively, the graphic controller 1575 may include a frame buffer that stores image data generated by the CPU 1505 or the like.

  The input / output controller 1584 connects the host controller 1582 to the hard disk drive 1540, the communication interface 1530, and the CD-ROM drive 1560, which are relatively high-speed input / output devices. The hard disk drive 1540 stores programs and data used by the CPU 1505. The communication interface 1530 is connected to the network communication device 1598 to transmit / receive programs or data. The CD-ROM drive 1560 reads a program or data from the CD-ROM 1595 and provides it to the hard disk drive 1540 and the communication interface 1530 via the RAM 1520.

  The input / output controller 1584 is connected to the ROM 1510, the flexible disk drive 1550, and the relatively low-speed input / output device of the input / output chip 1570. The ROM 1510 stores a boot program that is executed when the radiation imaging system is started up, a program that depends on the hardware of the radiation imaging system, and the like. The flexible disk drive 1550 reads a program or data from the flexible disk 1590 and provides it to the hard disk drive 1540 and the communication interface 1530 via the RAM 1520. The input / output chip 1570 connects various input / output devices via the flexible disk drive 1550 or a parallel port, serial port, keyboard port, mouse port, and the like.

  A program executed by the CPU 1505 is stored in a recording medium such as the flexible disk 1590, the CD-ROM 1595, or an IC card and provided by the user. The program stored in the recording medium may be compressed or uncompressed. The program is installed in the hard disk drive 1540 from the recording medium, read into the RAM 1520, and executed by the CPU 1505.

  The program executed by the CPU 1505 includes the image processing apparatus 120, the compressed moving image acquiring unit 201, the compressed moving image expanding unit 202, the feature region detecting unit 203, the image dividing unit 204, and the image described with reference to FIGS. It functions as the generation unit 205. Further, the program executed by the CPU 1505 causes the image processing apparatus 120 to be connected to the fixed value conversion unit 211, the image quality reduction unit 221, the encoding unit 231, the association processing unit 206 described with reference to FIGS. It functions as the output unit 207. The program executed by the CPU 1505 causes the image processing apparatus 120 to function as the input moving image quality control unit 280, the image quality reduction unit 281 and the inter-layer difference compression unit 282 described with reference to FIGS. .

  The program executed by the CPU 1505 causes the image processing apparatus 120 to function as the moving image acquisition unit 271, change amount detection unit 272, and recompression unit 273 described with reference to FIGS. 1 to 8. Further, the program executed by the CPU 1505 causes the image processing apparatus 170 to be connected to the compressed moving image acquisition unit 301, the association analysis unit 302, the compressed moving image decompression unit 311, the moving image generation unit 303, which have been described with reference to FIGS. And function as the output unit 304.

  The program shown above may be stored in an external storage medium. As the storage medium, in addition to the flexible disk 1590 and the CD-ROM 1595, an optical recording medium such as a DVD or PD, a magneto-optical recording medium such as an MD, a tape medium, a semiconductor memory such as an IC card, or the like can be used. Further, a storage device such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet is used as a recording medium, and is provided to the image processing device 120 and the image processing device 170 as a program via the network. Also good.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

1 shows an example of an image processing system 10 according to an embodiment. An example of a block configuration of the image processing apparatus 120 is shown. 2 shows an example of a block configuration of an image processing apparatus 170. 4 shows another example of a block configuration of the image processing apparatus 120. An example of the block configuration of the inter-layer difference compression units 282a and b is shown. An example of a block configuration of the recompression unit 270 is shown. An example of a method for compressing a moving image constituent image will be described. An example of a method for detecting an image change amount will be described. An example of the hardware configuration of the image processing apparatus 120 and the image processing apparatus 170 is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image processing system 100 Imaging device 110 Communication network 120 Image processing device 130 Person 140 Moving object 150 Monitoring object space 160 Space 170 Image processing device 180 Display device 201 Compressed moving image acquisition unit 202 Compressed moving image decompression unit 203 Feature area detection unit 204 Image division Unit 205 image generation unit 206 association processing unit 207 output unit 210 fixed value unit 211 fixed value unit 220 reduction unit 221 image quality reduction unit 230 encoding unit 231 encoding unit 231a background area moving image encoding unit 231b-d Features Region video encoding unit 240 Compression unit 270 Recompression unit 271 Video acquisition unit 272 Change amount detection unit 273 Recompression unit 273a Image decompression unit 273b Differential recompression unit 280 Input video image quality control unit 281 Image quality reduction unit 282 Inter-layer difference compression unit 285 motion solution Unit 286 motion encoding unit 287 difference processing unit 288 encoding unit 290 position difference information change unit 291 pixel value change unit 292 image decoding unit 293 image enlargement unit 294 difference target region determination unit 295 position difference information generation unit 296 difference pixel image generation Unit 297 spatial frequency domain conversion unit 298 quantization unit 299 frequency domain image quality conversion unit 301 compressed moving image acquisition unit 302 association analysis unit 310 compressed moving image expansion unit 311 compressed moving image expansion unit 303 moving image generation unit 304 output unit

Claims (8)

A feature region detection unit for detecting a plurality of feature regions having different types of features from a plurality of movie composition images included in the movie;
An image dividing unit that divides the plurality of moving image constituent images into a plurality of feature region moving images including each of the plurality of feature regions and a background region moving image including a background region other than the plurality of feature regions;
A compression unit that compresses the plurality of feature region videos and the background region movie with a predetermined compression strength for each feature type;
A moving image acquisition unit that acquires a moving image including a moving image constituent image having an intra-coded region from the plurality of compressed feature region moving images and the background region moving image;
A change amount detection unit that detects a change amount of an image between a moving image constituent image having the intra-coded region and another moving image constituent image;
A recompression unit that compresses the image of the intra-coded region of the moving image constituent image by inter encoding that refers to the other moving image forming image when the amount of change is smaller than a predetermined value;
Equipped with a,
The change amount detection unit detects the change amount between a feature region having an intra-coded region in the moving image constituent image and a feature region in the other moving image constituent image,
The recompressing unit refers to an image of the feature region having the intra-coded region when the amount of change is smaller than a predetermined value, and refers to the feature region in the other moving image constituent image. An image processing apparatus that compresses by encoding . The moving image acquisition unit acquires a moving image including an I picture that is a moving image constituent image having the intra-coded region,
The change amount detecting unit detects a change amount between the feature region in the moving image constituent image that is an I picture and the feature region in the other moving image constituent image,
The recompression unit compresses the moving picture constituent image, which is the I picture, by converting it into a P picture or a B picture that refers to the other moving picture constituent image when the amount of change is smaller than a predetermined value. The image processing apparatus according to claim 1 . The change amount detection unit detects a change amount between the feature region in the moving image constituent image that is an I picture and the feature region in the other moving image constituent image that is another I picture,
The recompression unit, when the amount of change is smaller than a predetermined value, refers to the moving picture constituent image that is the I picture, a P picture that refers to the other moving picture constituent image that is the other I picture, or The image processing apparatus according to claim 2 , wherein the image processing apparatus compresses the picture by converting it into a B picture. The recompression unit, when the amount of change is smaller than a predetermined value, the image difference between the feature region having the intra-coded region and the feature region in the other moving image constituent image The image processing apparatus according to claim 1 , wherein the image of the feature area having the intra-coded area is compressed. The recompression unit includes the position of the difference target region in the feature region of the other moving image constituent image that takes a difference from the feature region having the intra-coded region and the intra-coded region. The image of the feature region having the intra-coded region based on the position difference between the region and the difference between the feature region having the intra-coded region and the difference target region. The image processing device according to claim 4 , wherein the image processing device is compressed. The recompression unit
The feature region having the intra-coded region and the feature region in the other moving image constituent image are expanded, and the pixel information of the characteristic region having the intra-coded region and the other moving image forming image are obtained. An image decompression unit for obtaining pixel information of the feature region in
A differential recompression unit that compresses the image of the feature region having the intra-coded region based on the difference of the image generated based on the pixel information obtained by decompression by the image decompression unit;
The image processing apparatus according to claim 4 , comprising: A program for causing a computer to function as the image processing apparatus according to any one of claims 1 to 6. A feature region detection stage for detecting a plurality of feature regions having different types of features from a plurality of movie composition images included in the movie;
An image dividing step of dividing the plurality of moving image constituent images into a plurality of feature region moving images including each of the plurality of feature regions and a background region moving image including a background region other than the plurality of feature regions;
A compression step of compressing the plurality of feature region videos and the background region movie with a predetermined compression strength for each feature type;
A moving image acquisition step for acquiring a moving image including a moving image constituent image having an intra-coded region from the plurality of compressed feature region moving images and the background region moving image;
A change amount detecting step for detecting a change amount of an image between the moving image constituent image having the intra-coded region and another moving image constituent image;
A recompression step of compressing the image of the intra-coded region of the moving image constituent image by inter encoding referring to the other moving image forming image when the amount of change is smaller than a predetermined value. Prepared ,
In the change amount detection step, the change amount between a feature region having an intra-coded region in the moving image constituent image and a feature region in the other moving image constituent image is detected,
In the re-compression step, when the amount of change is smaller than a predetermined value, an image of the feature region having the intra-coded region is referred to the feature region in the other moving image constituent image. An image processing method for compressing by encoding .

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