JP4454424B2 - Image quality correction apparatus and imaging apparatus - Google Patents

Description

  The present invention has a function of generating a correction signal for enhancing an edge related to a level change of a luminance signal based on a luminance signal included in an image, and adding the generated correction signal to the luminance signal to enhance the edge. The present invention relates to an image quality correction apparatus and an imaging apparatus including the image quality correction apparatus.

  FIG. 10 is a block diagram showing a configuration of a conventional image quality correction apparatus 401, and FIG. 11 is for correcting a luminance signal in a horizontal line of a composite image in which two images to be combined are adjacent, and an edge related to the luminance signal. It is a figure which shows the level change of the luminance signal which added the correction signal of this, and this correction signal.

  The conventional image quality correction apparatus 401 uses the first luminance image L1 that the input first synthesized image has for each pixel and the second luminance signal L2 that the second synthesized image has for each pixel, to obtain a first synthesized image. And a composite image generation unit 411 that generates a composite image in which the second composite image is adjacent to the left and right in the horizontal direction and outputs the luminance signal L of the generated composite image to the delay unit 414 and the correction signal generation unit 412. ing. FIG. 11A shows the level change of the luminance signal L, and the portion indicated by the point A is a boundary between two synthesized images. The luminance signal L has step edges at a boundary point A and a point B in the second synthesized image on the right side in the drawing. The step edge is an example of an edge related to the spatial change in the level of the luminance signal L, and the edge related to the spatial change in the level means an edge related to the change in the luminance signal L in the density region of the image. .

  Based on the luminance signal L output from the composite image generation unit 411, the correction signal generation unit 412 generates a correction signal R that enhances the edge related to the spatial change in the level of the luminance signal L and improves the sharpness of the image. Then, the generated correction signal R is output to the multiplier 413. The correction signal R is generated by, for example, secondary differentiation of the luminance signal L.

  The multiplication unit 413 multiplies the correction signal R by the level adjustment parameter m output from the control unit 428 and outputs a correction signal R ′ obtained by multiplying the level adjustment parameter m to the addition unit 415. FIG. 11B shows a level change of the correction signal R ′ when the level adjustment parameter m is a constant level.

  The delay unit 414 is a circuit that delays the luminance signal L output from the synthesized image generation unit 411 and outputs the delayed signal to the addition unit 415. The delay unit 414 outputs the luminance signal L output from the delay unit 414 and the multiplication unit 413. The luminance signal L is delayed so that the correction signal R ′ is input to the adder 415 at the same timing.

  The addition unit 415 adds the correction signal R ′ output from the multiplication unit 413 to the luminance signal L output from the delay unit 414, and outputs the luminance signal L ′ obtained by adding the correction signal R ′ to the display unit. FIG. 11C shows the level change of the luminance signal L ′. The luminance signal L ′ added with the correction signal R ′ undershoots and overshoots at the edges indicated by the points A and B, and the edge of the luminance signal L is emphasized.

  In the image quality correction apparatus 401 configured as described above, the sharpness of the image is improved by correcting the level of the luminance signal L of the image and enhancing the edge as shown in FIGS. Image quality can be improved.

On the other hand, there is an image quality correction apparatus that does not include a composite image generation unit and performs similar image quality correction on a single image (for example, Patent Document 1). In the image quality correction apparatus, the image quality can be improved by enhancing the edge of the luminance signal in the same manner.
JP 2002-152553 A

  However, when two adjacent synthesized images have different tones, the level of the luminance signal of the first and second synthesized images on the left and right greatly changes at the boundary between the two synthesized images. Edges are generated. Since the correction signal is generated by the second derivative of the luminance signal, as shown in FIG. 11, the edge related to the luminance signal near the boundary is strongly emphasized compared to the edge of the luminance signal included in the single image, As a result, there is a problem in that the boundary portion glare abnormally and image quality deteriorates.

  In addition, when emphasizing the edge related to the luminance signal of a single image, glare at the edge that becomes a cut in the image is more noticeable than at the center of the image, and the image quality is reduced at the edge of the image. There was a problem.

  The present invention has been made in view of such circumstances, and is provided with level adjustment means for adjusting the level of the correction signal in accordance with the position of the pixel, thereby reducing the image quality due to the addition of the correction signal. It is an object of the present invention to provide an image quality correction apparatus that can be appropriately suppressed depending on the situation.

  In addition, the image forming apparatus includes a unit that generates a composite image in which a plurality of composite images are adjacent to each other, and is configured to greatly reduce the level of the correction signal related to the pixels as the pixels are closer to the boundary between the composite images. Accordingly, another object of the present invention is to provide an image quality correction apparatus that can suppress deterioration in image quality due to addition of correction signals in the vicinity of the boundary portion of a composite image.

  Further, by specifying a boundary portion between the synthesized images based on the horizontal synchronization signal and / or the vertical synchronization signal, and performing a level adjustment of the correction signal in a required pixel range including the specified boundary portion, It is another object of the present invention to provide an image quality correction apparatus that can suppress deterioration in image quality in the vicinity of the boundary.

  Furthermore, by correcting the level of the correction signal at a reduction rate that is symmetric with respect to the boundary portion, the sharpness of the image is corrected symmetrically to generate an image with a balanced image quality. Another object of the present invention is to provide an image quality correction apparatus capable of performing the above.

  Furthermore, the level of the correction signal related to the luminance signal included in each of the plurality of images is adjusted according to the position of the pixel, the level-adjusted correction signal is added to the luminance signal, and the luminance signal added with the correction signal is added. It is another object of the present invention to provide an image quality correction apparatus capable of generating a composite image in which deterioration of image quality due to addition of a correction signal is appropriately suppressed by generating a composite image in which the respective images are adjacent to each other. Objective.

  Furthermore, the present invention provides an image quality correction apparatus capable of suppressing deterioration in image quality in the vicinity of the edge by configuring the pixel closer to the edge of the image to greatly reduce the level of the correction signal related to the pixel. For other purposes.

  Furthermore, the edge of the image is specified based on the horizontal synchronization signal and / or the vertical synchronization signal, and the level of the correction signal is adjusted in the required pixel range including the specified edge. It is another object of the present invention to provide an image quality correction apparatus that can suppress degradation in image quality due to addition of correction signals in the vicinity.

  Furthermore, it is possible to provide an image quality correction apparatus capable of generating an image with a balanced image quality by configuring the correction signal level to be reduced at the same reduction rate in each of a plurality of pixel ranges. For other purposes.

  Furthermore, an image sensor that captures one image in parallel as a plurality of divided images and the image quality correction device, and generation and image quality correction of a composite image in which a plurality of images captured by the image sensor are adjacent to each other are provided. By providing the above, the imaging device capable of reading out the luminance signal of the image at a higher speed and appropriately correcting the image quality of the read luminance signal is provided compared to the case of imaging as one image. For other purposes.

The image quality correction apparatus according to the present invention generates a correction signal for correcting a luminance signal so as to emphasize an edge related to a spatial change in the level of the luminance signal, based on the luminance signal that the image has for each pixel. In an image quality correction apparatus comprising a signal generation means, wherein the level of the correction signal generated by the correction signal generation means is adjusted and added to the luminance signal, the level of the correction signal generated by the correction signal generation means is Level adjustment means for adjusting according to the position of the pixel, first and second parameters corresponding to the position of the predetermined pixel, level adjustment parameter for adjusting the level by multiplying the correction signal, and according to the position of the pixel A memory storing weight parameters for weighting the level adjustment parameters, the first and second parameters, and the level adjustment parameters; And by outputting a wait parameter to the level adjusting unit, and a control unit for controlling the operation of said level adjusting means, and adding means for adding the correction signal adjusted by said level adjustment means to said luminance signal, said The level adjusting means includes a counter that outputs a count value counted in synchronization with the horizontal synchronization signal and / or the vertical synchronization signal, the count value output from the counter, and the first and second output from the control unit. Based on a position selection unit that compares parameters and outputs a position parameter having a value corresponding to a relative position with respect to a predetermined pixel, a position parameter output from the position selection unit, and a weight parameter output from the control unit A weight processing unit that outputs a weight signal corresponding to the position parameter, and a signal output from the weight processing unit. A first multiplication unit that multiplies the weight adjustment signal and the level adjustment parameter output from the control unit, and outputs a level adjustment signal obtained by the multiplication, and the level adjustment signal output from the first multiplication unit and the correction signal generation And a second multiplier for multiplying the correction signal generated by the means .

  In the present invention, the level adjusting means adjusts the level of the correction signal for enhancing the edge related to the luminance signal in accordance with the position of the pixel so that the edge of the luminance signal is not excessively emphasized. The adding means adds the correction signal whose level has been adjusted by the level adjusting means to the luminance signal. Therefore, undershoot and overshoot that occur at the edge of the luminance signal due to the addition of the correction signal can be appropriately suppressed according to the position of the pixel, and abnormal glare that occurs in part of the image can be suppressed.

  An image quality correction apparatus according to the present invention includes a generation unit that generates a composite image in which a plurality of combined images are adjacent to each other, and the level adjustment unit corrects a luminance signal included in the composite image generated by the generation unit. When the correction signal is adjusted, the level of the correction signal related to the pixel is greatly (smaller) reduced as the pixel is closer (far) from the boundary between the combined images.

  In the present invention, the generation means generates an image in which a plurality of synthesized images are adjacent. The level adjustment means can adjust the level of the correction signal so that the pixel closer to the boundary where the level change of the luminance signal is larger does not overemphasize the edge of the luminance signal. Therefore, it is possible to naturally suppress abnormal glare of the image at the boundary portion.

  In the image quality correction apparatus according to the present invention, the generation unit generates a composite image in which a plurality of composite images are adjacent in the horizontal direction and / or the vertical direction, and the level adjustment unit includes a horizontal synchronization signal. In addition, the boundary portion is specified based on the vertical synchronization signal, and the level of the correction signal is reduced in a required pixel range including the specified boundary portion.

  In the present invention, the boundary portion of the composite image in which the combined image is adjacent in the horizontal direction and / or the vertical direction is specified based on the horizontal synchronization signal and / or the vertical synchronization signal, and the required portion including the boundary portion is specified. The level of the correction signal is reduced in the pixel range. Accordingly, it is possible to suppress abnormal glare of the image in a required pixel range including the boundary portion. The horizontal direction and / or the vertical direction means the horizontal direction or the vertical direction, and the horizontal direction and the vertical direction. The horizontal synchronization signal and / or the vertical synchronization signal are a horizontal synchronization signal or a vertical synchronization signal, and a horizontal synchronization signal. And a vertical synchronization signal.

  The image quality correction apparatus according to the present invention is characterized in that the level adjusting means reduces the level of the correction signal at a symmetric reduction rate with respect to the boundary portion.

  In the present invention, since the level of the correction signal is adjusted at a substantially symmetric reduction rate with respect to the boundary portion, it is possible to generate an image in which the sharpness of the image is balanced at the boundary portion.

The image quality correction apparatus according to the present invention corrects a luminance signal so as to emphasize an edge related to a spatial change in the level of the luminance signal, based on the luminance signal that each of the first image and the second image has for each pixel. first a correction signal generating unit and the second correction signal generating unit, a correction signal by the level adjusting said first correction signal generating unit and the second correction signal generating unit has generated, the correction signal to generate a correction signal An image quality correction apparatus that adds to the luminance signal according to each of the above, and adjusts the level of each of the correction signals generated by the first correction signal generation unit and the second correction signal generation unit according to the position of the pixel and level adjusting means for the first parameter and the second parameter corresponding to a position of a predetermined pixel, level adjustment parameter for level adjustment by multiplying the correction signal, and level adjustment para depending on the position of the pixel A memory storing weight parameters for weighting the data, and controlling the operation of the level adjusting means by outputting the first and second parameters, the level adjusting parameter and the weight parameter to the level adjusting means. A control unit that adds the correction signal adjusted by the level adjusting unit to the luminance signal related to the correction signal, and a luminance signal after the addition unit adds the correction signal to each pixel . A composite image generation unit that generates a composite image in which the one image and the second image are adjacent to each other, and the level adjusting unit outputs a count value counted in synchronization with the horizontal synchronization signal and / or the vertical synchronization signal. The counter is compared with the count value output from the counter and the first and second parameters output from the control unit, and a predetermined value is displayed. A position selection unit that outputs a position parameter having a value corresponding to a relative position with respect to the position parameter, a position parameter output from the position selection unit, and a weight signal corresponding to the position parameter based on the weight parameter output from the control unit , A first multiplication unit that outputs a level adjustment signal obtained by multiplying the weight signal output from the weight processing unit and the level adjustment parameter output from the control unit, and the second multiplication unit. A second multiplier that multiplies the level adjustment signal output from the first multiplier and the correction signal generated by the first correction signal generator; the level adjustment signal and the second correction signal output from the first multiplier; And a third multiplication unit that multiplies the correction signal generated by the generation unit .

  In the present invention, the plurality of correction signal generation units generate correction signals for enhancing the edges related to the luminance signals included in each of the plurality of images. Then, the level adjustment means adjusts the level of the correction signal related to each of the plurality of images, and the adjusted correction signal is added to each luminance signal. The generation unit generates a composite image in which a plurality of images corrected by adding correction signals are adjacent to each other. Therefore, the undershoot and overshoot that occur at the edge of the luminance signal due to the addition of the correction signal can be appropriately suppressed according to the pixel position, and abnormal glare of the image can be suppressed. Can be generated.

  The image quality correction apparatus according to the present invention is characterized in that the level adjustment means reduces the level of the correction signal related to the pixel larger (smaller) as the pixel is closer (far) from the edge of the image. To do.

  In the present invention, the level adjusting means can adjust so that the level of the correction signal is greatly reduced so that the edge of the luminance signal is not excessively emphasized as the pixel is closer to the edge of the image. Therefore, it is possible to suppress abnormal glare of the image at the end.

  In the image quality correction apparatus according to the present invention, the level adjustment unit specifies the end portion based on a horizontal synchronization signal and / or a vertical synchronization signal, and the level of the correction signal in a required pixel range including the specified end portion. It is characterized by reducing the above.

  In the present invention, the edge of the image is specified based on the horizontal synchronization signal and / or the vertical synchronization signal, and the level of the correction signal is reduced in a required pixel range including the edge. Therefore, it is possible to suppress abnormal glare of the image in a required pixel range including the end portion.

  In the image quality correction apparatus according to the present invention, when the level adjusting unit reduces the level of the correction signal in each of the plurality of pixel ranges including the end portion, the level of the correction signal is reduced by the same reduction rate in each pixel range. It is characterized by being reduced by this.

  In the present invention, since the correction signal whose level is reduced at the same reduction rate in the vicinity of each of the plurality of end portions is added to the luminance signal, it is possible to generate an image with a balanced image sharpness. it can.

  An image pickup apparatus according to the present invention includes an image pickup element that picks up an image as a plurality of divided images, and any one of the image quality correction apparatuses described above, and the image quality correction apparatus includes an image picked up by the image pickup element. The image quality correction is performed.

  In the present invention, since the image pickup device picks up one image in parallel as a plurality of divided images, the image is captured at a higher speed than when a luminance signal related to one image is read from the image pickup device. The luminance signal can be read out. Then, a composite image in which sharpness is appropriately emphasized can be obtained by correcting the luminance signal read out in a divided manner and processing of a generating unit that generates a composite image in which the divided images are adjacent to each other.

  In the image quality correction apparatus according to the present invention, it is possible to obtain an image with high sharpness and appropriately suppressed image glare according to the position of the pixel.

  In the image quality correction apparatus according to the present invention, it is possible to obtain a composite image having high sharpness and appropriately suppressing image glare at the boundary portion between the composite images.

  With the image quality correction apparatus according to the present invention, it is possible to obtain an image with high sharpness and in which the glare of the image is appropriately suppressed in a required pixel range including the boundary portion between the combined images.

  In the image quality correction apparatus according to the present invention, it is possible to generate an image with a sharpness balance at the boundary.

  With the image quality correction apparatus according to the present invention, it is possible to obtain a composite image with high sharpness and reduced image glare.

  In the image quality correction apparatus according to the present invention, it is possible to obtain an image with high sharpness and in which glare of the image is appropriately suppressed at the edge of the image.

  In the image quality correction apparatus according to the present invention, it is possible to obtain an image with high sharpness and in which glare of the image is appropriately suppressed in a required pixel range including the edge of the image.

  In the image quality correction apparatus according to the present invention, it is possible to obtain an image with a balanced sharpness at a plurality of ends.

  In the image pickup apparatus according to the present invention, it is possible to pick up an image at a higher speed than in the case of picking up as one image, and it is possible to appropriately enhance the sharpness of the picked up image.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
(Embodiment 1)
FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus including an image quality correction apparatus 1 (see FIG. 2) according to Embodiment 1 of the present invention. The imaging apparatus according to Embodiment 1 includes a lens 20a, an imaging element 20b, a synchronization signal generation unit 21, an imaging signal processing unit 22, an image processing unit 23, a display unit 24, a video codec unit 25, a recording / playback unit 26, and a control. The unit 28 is provided.

  The lens 20a collects light from the subject, and the light collected by the lens 20a forms an image on the image sensor 20b. The image sensor 20 b is a CCD that converts an image of a formed subject into an analog image signal, and outputs the image signal to the image signal processor 22 in two channels. The output of the imaging signal from the image sensor 20b is performed in synchronization with the synchronization signal generated by the synchronization signal generator 21 and input to the image sensor 20b. The imaging signal output to the imaging signal processing unit 22 with two channels is the imaging signal of the first composite image captured by the left half light receiving surface of the image sensor 20b and the second image captured by the right half light receiving surface. It is an imaging signal of a synthesized image.

  The imaging signal processing unit 22 AD-converts the two-channel imaging signals output from the imaging element 20 b into digital image data, and outputs the AD-converted image data to the image processing unit 23. The image processing unit 23 includes the image quality correction device 1 (see FIG. 2), and uses the first luminance signal L1 and the second luminance signal L2 of the first composite image from the image data output from the imaging signal processing unit 22. The image quality correction apparatus 1 is configured to perform image quality correction and composition of the generated and generated images related to the first and second luminance signals L1 and L2.

  Then, the image processing unit 23 outputs a luminance signal related to the image subjected to image quality correction and synthesis in the image quality correction apparatus 1 to the display unit 24 to display the image. Further, the image processing unit 23 outputs image data relating to the image displayed on the display unit 24 to the video codec unit 25. The imaging signal processing unit 22 and the image processing unit 23 perform processing in synchronization with the synchronization signal output from the synchronization signal generation unit 21. In particular, the synchronization signal generation unit 21 outputs a horizontal synchronization signal hd and a vertical synchronization signal vd to the image processing unit 23.

  The video codec unit 25 compresses the image data related to the luminance signal by a compression / decompression method such as MPEG or Motion JPEG, and outputs the compressed image data to the recording / reproducing unit 26. The recording / reproducing unit 26 records the compressed image data on a removable recording medium 27 such as a semiconductor memory, a DVD, or a magnetic tape. The recording / reproducing unit 26 has a function of reading the recorded image data from the recording medium 27 and reproducing it.

  The imaging element 20b, the imaging signal processing unit 22, the image processing unit 23, the video codec unit 25, and the recording / reproducing unit 26 are controlled by a control unit 28 of a microcomputer.

  FIG. 2 is a block diagram showing the configuration of the image quality correction apparatus 1 according to the first embodiment, and FIG. 3 is a timing chart showing the operation of the image quality correction apparatus 1 according to the first embodiment. The image quality correction apparatus 1 according to Embodiment 1 includes a composite image generation unit 11, a correction signal generation unit 12, a level adjustment unit 13, a delay unit 14, and an addition unit 15, and is controlled by the control unit 28 of the imaging apparatus. It is configured to be.

  The composite image generation unit 11 generates the first composite image and the second composite image from the first luminance signal L1 that the first composite image has for each pixel and the second luminance signal L2 that the second composite image has for each pixel. An image in which the synthesized image is adjacent in the horizontal direction is generated, and a luminance signal L that the generated image has for each pixel is output to the correction signal generation unit 12 and the delay unit 14. The left half of the image generated by the composite image generation unit 11 is the first composite image, and the right half is the second composite image. Based on the luminance signal L output from the composite image generation unit 11, the correction signal generation unit 12 generates a correction signal R that corrects the luminance signal L so that an edge related to a spatial change in the level of the luminance signal L is enhanced. The generated correction signal R is output to the level adjusting means 13. The correction signal R is generated by secondary differentiation of the luminance signal L.

  The level adjustment means 13 includes a counter 13a, a position selection unit 13b, a weight processing unit 13c, a first multiplication unit 13d, and a second multiplication unit 13e, which will be described later, and each unit is controlled by the control unit 28. When the control unit 28 controls each unit, the level adjusting unit 13 adjusts the level of the correction signal R output from the correction signal generating unit 12 and outputs the adjusted correction signal R ′ to the adding unit 15. The delay unit 14 has a function of delaying the luminance signal L output from the composite image generation unit 11 for a predetermined time and outputting the delayed luminance signal L to the addition unit 15, and is output to the addition unit 15. The timings of the luminance signal L and the correction signal R ′ corresponding to the luminance signal L are matched. The adding unit 15 adds the correction signal R ′ output from the level adjusting unit 13 to the luminance signal L output from the delay unit 14 and adds the correction signal R ′ to the luminance signal L ′. The data is output to the codec unit 25.

  The control unit 28 includes a memory, and the memory includes a first parameter p1 and a second parameter p2 corresponding to a predetermined pixel position, in particular, a first portion corresponding to a boundary portion between the first synthesized image and the second synthesized image. The parameter p1 and the second parameter p2 are stored. The first parameter p1 indicates the pixel position of the boundary portion on the first composite image side, and the second parameter p2 indicates the pixel position of the boundary portion on the second composite image side. The memory also stores a level adjustment parameter m for adjusting the level by multiplying the correction signal R, and a weight parameter w (p) for weighting the level adjustment parameter m according to the position of the pixel. The level adjustment parameter m is a parameter that increases or decreases according to the level of the luminance signal L. For example, when the level of the luminance signal L is the maximum level or the minimum level, the level of the luminance signal L is the intermediate level. It is a parameter that is smaller than that. p is a position parameter indicating the position of a specific pixel. The control unit 28 uses the first parameter p1, the second parameter p2, the weight parameter w (p), and the level adjustment parameter m stored in the memory, respectively, as the position selection unit 13b, the weight processing unit 13c, and the first multiplication. Each part is controlled by outputting to the part 13d.

  The counter 13a includes a clock generation unit, and counts the clock generated by the clock generation unit as shown in FIG. 3 using the falling edge of the horizontal synchronization signal hd output from the synchronization signal generation unit 21 as a trigger for resetting and counting. The count value N (N = 0, 1, 2, 3...) Is output to the position selection unit 13b. For example, when the vertical synchronization signal frequency is 59.94 Hz and the horizontal synchronization signal hd frequency is 15.734 kHz, the number of effective pixels in the horizontal direction is 720 pixels, and the horizontal blanking period is approximately 10.2 μsec. Since the frequency is 13.5 MHz, the clock frequency generated by the clock generation unit is 13.5 MHz, which is the same as the sampling frequency.

  The position selection unit 13b is controlled by the control unit 28, and compares the first and second parameters p1 and p2 indicating the boundary output from the control unit 28 with the count value N output from the counter 13a. The position parameter p is output to the weight processing unit 13c according to the comparison result. Specifically, when the count value N is within the pixel range of p1-9 to p1 corresponding to the pixel on the left side of the boundary, the difference N−p1 between the first parameter p1 and the count value N is set as the position parameter p. (However, when −9 ≦ p ≦ 0) and the count value N is within the pixel range of p2 to p2 + 9 corresponding to the pixel on the right side of the boundary, the difference N between the second parameter p2 and the count value N -P2 is output as the position parameter p (where 0 ≦ p ≦ 9). When the first and second parameters p1 and p2 indicate positions corresponding to the boundary portions of the first and second combined images, and the position parameter p is positive, the position parameter p is the first combined image. 3 corresponds to the position of the pth pixel on the right side in FIG. 3 from the boundary portion of the second synthesized image, and corresponds to the position of the | p | th pixel on the left side from the boundary portion when the position parameter p is negative.

  The weight processing unit 13c is controlled by the control unit 28. When the position parameter p is output from the position selection unit 13b, the weight processing unit 13c is based on the position parameter p and the weight parameter w (p) output from the control unit 28. , A function of outputting a weight signal W = w (p) corresponding to the position parameter p to the first multiplier 13d. As shown in FIG. 3, the weight parameter w (p) has eight levels of 0 to 7, and the weight processing unit 13 c has the positional parameters p = ± 9, ± 8, ± 7. , A weight signal W with a weight parameter w (p) = 7 is output. Similarly, the weight processing unit 13c performs the weight parameter w (p) = 6, 5, 4, with respect to the position parameter p = ± 6, ± 5, ± 4, ± 3, ± 2, ± 1, 0. When the weight signals W of 3, 2, 1, 0 are respectively output and the position parameter p is not output, the weight processing unit 13c outputs the weight signal W = 7 to the first multiplication unit 13d.

  The first multiplication unit 13d multiplies the weight signal W output from the weight processing unit 13c by the level adjustment parameter m related to the level adjustment of the correction signal R output from the control unit 28, and multiplies the weight signal W by level adjustment. The signal m ′ = m · W is output to the second multiplier 13e. Since the level adjustment signal m ′ is a signal obtained by multiplying the level adjustment parameter m by the weight signal W that becomes smaller as it approaches the boundary, as shown in FIG. 3, the level adjustment signal m ′ becomes a small level signal in the vicinity of the boundary.

  The second multiplication unit 13e multiplies the level adjustment signal m ′ output from the first multiplication unit 13d by the correction signal R output from the correction signal generation unit 12, and the correction signal R ′ multiplied by the level adjustment signal m ′. = R · m ′ is output to the adder 15.

  FIG. 4 shows the luminance signal L of the synthesized image, the correction signal R generated based on the luminance signal L, the level adjustment signal m ′ for adjusting the level of the correction signal R, and the correction whose level is adjusted by the level adjustment means 13. It is a schematic diagram which shows the luminance signal L 'to which signal R' was added. 4 (a) and 4 (b) are diagrams showing a change in level of the luminance signal L and the correction signal R generated based on the luminance signal L similar to those in FIGS. 11 (a) and 11 (b). FIG. 4C shows a level-adjusted signal m ′ that has been weighted when the level adjustment parameter m is constant. FIG. 4D shows a corrected luminance signal L ′ obtained by adding the correction signal R ′ whose level is adjusted by multiplying by the level adjustment signal m ′ to the luminance signal L.

  In the image quality correction apparatus 1 configured in this way, the level of the correction signal R is adjusted by the level adjustment signal m ′ at the boundary between the first and second combined images, and therefore FIG. ), The edge enhancement at the boundary can be appropriately suppressed as compared with FIG. That is, the undershoot and overshoot that occur at the edge of the luminance signal L ′ can be moderately suppressed so as not to become too large. Therefore, it is possible to generate an image having high sharpness and suppressing glare of the image at the boundary portion. In addition, since the level of the level adjustment signal m ′ is reduced as the pixel is closer to the boundary portion, the glare of the image in the vicinity of the boundary portion can be suppressed smoothly. Further, since the level of the level adjustment signal m ′ is adjusted by symmetrical weighting with respect to the boundary portion, it is possible to suppress the glare of the image with a good left / right balance.

  Furthermore, since the imaging signal is acquired from the imaging element 20b with two channels, the imaging signal can be acquired at a higher speed than when the imaging signal is acquired from the imaging element 20b with one channel. In addition, it is possible to synthesize the images related to the acquired two-channel imaging signals, improve the sharpness of the synthesized image, and generate an image with reduced glare at the boundary.

  In the first embodiment, the boundary portion of the synthesized image is specified by the position selection unit 13b to suppress glare of the image in the vicinity of the boundary portion. You may comprise so that glare may be suppressed.

  FIG. 5 is a timing chart showing the operation of the image quality correction apparatus 1 according to the modification of the first embodiment. The control unit 28 according to the modified example uses the first parameter p1 corresponding to the position of the pixel at the right end of the image and the first parameter p1 corresponding to the position of the pixel at the right end of the image as the first and second parameters p1 and p2 corresponding to the position of the predetermined pixel. The second parameter p2 corresponding to the position is stored in the memory. Other configurations and functions are the same as those in FIG.

  In the image quality correction apparatus 1 according to the modified example, when the count value N is within the pixel range of p1-9 to p1 corresponding to the pixels near the right end of the image, the position selection unit 13b sets the first parameter p1. The difference N−p1 from the count value N is output to the weight processing unit 13c as the position parameter p (where −9 ≦ p ≦ 0). Since the position reference of the position parameter p is at the right end of the image, as shown in FIG. 5, the levels of the weight parameter w (p) and the level adjustment signal m ′ are smaller as they are closer to the right end of the image. Similarly, when the count value N is within the pixel range of p2 to p2 + 9 corresponding to the pixels near the left end of the image, the position selection unit 13b calculates the difference N−p2 between the second parameter p2 and the count value N, The position parameter p (where 0 ≦ p ≦ 9) is output to the weight processing unit 13c. The levels of the weight parameter w (p) and the level adjustment signal m ′ are smaller as they are closer to the left end of the image. Therefore, as shown in FIG. 5, since the level of the correction signal R ′ that has been level-adjusted by multiplication of the level adjustment signal m ′ also decreases as it approaches both ends of the image, the correction signal R ′ is changed to the luminance signal L. The glare of the image at both ends of the image due to the addition can be suppressed.

  In the modified example, the image quality correction processing is performed on the image synthesized by the synthesized image generating unit 11, but the synthesized image generating unit 11 is not provided, and an input single image is processed. Image quality correction processing may be performed.

In the first embodiment, the level-corrected correction signal is added to the luminance signal related to the captured image. However, the present invention is not limited to this, and is not limited to the image reproduced by the recording / reproducing unit or the image input to the imaging apparatus. A correction signal whose level has been adjusted may be added to the luminance signal.
Furthermore, the image quality correction apparatus 1 is adapted to an imaging apparatus, but is not limited to this, and may be applied to a digital still camera, a DVD player, a personal computer, or the like.

(Embodiment 2)
FIG. 6 is a block diagram showing the configuration of the image quality correction apparatus 101 according to Embodiment 2 of the present invention, and FIG. 7 is a timing chart showing the operation of the image quality correction apparatus 101 according to Embodiment 2 of the present invention. An image quality correction apparatus 101 according to Embodiment 2 includes a composite image generation unit 111, a correction signal generation unit 12, a level adjustment unit 113, a delay unit 14, and an addition unit 15, and is controlled by the control unit 28. .

  The synthesized image generation unit 111 includes a first luminance signal L1 that the first synthesized image input from the outside or the video codec unit 25 or the like has for each pixel, and a second luminance signal L2 that the second synthesized image has for each pixel. Then, the image in which the first and second combined images are adjacent in the vertical direction is combined, and the luminance signal L that the combined image has for each pixel is output to the correction signal generation unit 12 and the delay unit 14. The upper half of the image generated by the composite image generation unit 111 is the first composite image, and the lower half is the second composite image. The processing performed by the correction signal generation unit 12, the delay unit 14, and the addition unit 15 is the same as that in the first embodiment.

  The level adjustment unit 113 includes a counter 113a, a position selection unit 113b, a weight processing unit 113c, a first multiplication unit 113d, and a second multiplication unit 113e. The counter 113a includes a clock generation unit, resets at the falling edge of the vertical synchronization signal vd output from the synchronization signal generation unit 21, and triggers on the horizontal synchronization signal hd to count up. Then, as shown in FIG. 7, the clock generated by the clock generation unit is counted up, and the count value N (0, 1, 2, 3,...) Is output to the position selection unit 113b. The frequency of the clock is 59.94 Hz which is the same as the frequency of the vertical synchronization signal.

  The control unit 28 stores a first parameter p101 and a second parameter p102 corresponding to the pixel position of the boundary portion between the first combined image and the second combined image, and the control unit 28 stores the first and second parameters. p101 and p102 are output to the position selection unit 113b. The first parameter p101 indicates the pixel position of the boundary portion of the first composite image, and the second parameter p102 indicates the pixel position of the boundary portion of the second composite image.

  Other configurations, operations, and effects of the image quality correction apparatus 101 according to the second embodiment are the same as the configurations, functions, and effects of the image quality correction apparatus according to the first embodiment. A detailed description thereof will be omitted.

  In the image quality correction apparatus 101 configured as described above, the upper first synthesized image and the lower second synthesized image are synthesized. As shown in FIG. 7, in the vicinity of the boundary between the first and second combined images, the closer to the boundary, the smaller the weight parameter w (p) and the level adjustment signal m ′, and the level adjustment signal m ′ The level of the correction signal R ′ whose level is adjusted by multiplication is also smaller as it is closer to the boundary. Therefore, it is possible to generate an image having high sharpness and suppressing glare of the image at the boundary portion of the image.

(Embodiment 3)
FIG. 8 is a block diagram showing a configuration of image quality correction apparatus 201 according to Embodiment 3 of the present invention. The image quality correction apparatus 201 according to Embodiment 3 includes a composite image generation unit 211, a correction signal generation unit 12, a level adjustment unit 213, a delay unit 14, an addition unit 15, and a control unit 28.

  The synthesized image generation unit 211 receives the first to fourth luminance signals L1, L2, L3, and L4 included in the first to fourth synthesized images input from the outside or the video codec unit 25 or the like from the first to fourth luminance signals. An image in which the fourth synthesized image is adjacent in 2 rows and 2 columns in the horizontal direction and the vertical direction is generated, and the luminance signal L that the generated image has for each pixel is output to the correction signal generation unit 12 and the delay unit 14. The upper left part of the image generated by the composite image generation unit 211 is a first composite image, the upper right part is a second composite image, the lower left part is a third composite image, and the lower right part is a fourth composite image.

  The level adjustment unit 213 includes a first counter 213a, a first position selection unit 213b, a first weight processing unit 213c, a first multiplication unit 213d, and a second counter similar to those in the first embodiment. 213f, a second position selection unit 213g, a second weight processing unit 213h, and a third multiplication unit 213i. A horizontal synchronization signal hd is input to the first counter 213a, and a vertical synchronization signal vd is input to the second counter 213f. The first multiplier 213d outputs the first level adjustment signal m1 ′ weighted in the vicinity of the horizontal boundary of the first to fourth combined images to the second multiplier 213e in the same manner as in the first embodiment. To do. The third multiplication unit 213i outputs the second level adjustment signal m2 ′ weighted in the vicinity of the vertical boundary portion of the first to fourth combined images to the second multiplication unit 213e in the same manner as in the second embodiment. To do. The correction signal generation unit 12 is configured to output the correction signal R to the second multiplication unit 213e, and the second multiplication unit 213e performs the first multiplication on the correction signal R output from the correction signal generation unit 12. The first and second level adjustment signals m1 ′ and m2 ′ output from the unit 213d and the third multiplication unit 213i are multiplied, and the correction signal R ′ obtained by multiplying the first and second level adjustment signals m1 ′ and m2 ′ is added. To the unit 15.

  The control unit 28 includes first and second parameters p1 and p2 similar to those in the first embodiment, first and second parameters p101 and p102 similar to those in the second embodiment, weight parameters w (p), and the second embodiment. First and second level adjustment parameters m1 and m2 similar to 1 are stored in the memory. The control unit 28 sets the first parameter p1 and the second parameter p2 to the first position selection unit 213b, the first parameter p101 and the second parameter p102 to the second position selection unit 213g, and the weight parameter w (p) to the first. The first level adjustment parameter m1 is output to the first multiplication unit 213d and the second level adjustment parameter m2 is output to the third multiplication unit 213i to the weight processing unit 213c and the second weight processing unit 213h, and each unit is controlled. It is.

  The other configurations, operations, and effects of the image quality correction apparatus 201 according to Embodiment 3 are the same as the configurations, operations, and effects of the image quality correction apparatus according to Embodiment 1 or 2, so Are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the image quality correction apparatus 201 configured as described above, it is possible to combine images in which the first to fourth combined images are adjacent to each other in the horizontal direction and the vertical direction, and to correct the image quality of the combined image. Thus, it is possible to generate an image with high sharpness and in which glare of the image at the boundary portion is suppressed.

(Embodiment 4)
FIG. 9 is a block diagram showing a configuration of an image quality correction apparatus 301 according to Embodiment 4 of the present invention. The image quality correction apparatus 301 according to the present invention adjusts the level of the luminance signal L11 of the first image input from the outside or the video codec unit 25, etc., in the same manner as the first delay unit 314a, 1 correction signal generation part 312a and the 1st addition part 315a are provided. In addition, the image quality correction apparatus 301 adjusts the level of the luminance signal L12 of the second image input from the outside or the video codec unit 25, etc. A signal generation unit 312b and a second addition unit 315b are provided. Furthermore, in the image quality correction apparatus 301, the levels of the correction signal R11 generated by the first correction signal generation unit 312a based on the luminance signal L11 and the correction signal R12 generated by the second correction signal generation unit 312b based on the luminance signal L12, respectively. And level adjustment means 313 for outputting the corrected signals R11 ′ and R12 ′ whose levels have been adjusted to the first addition unit 315a and the second addition unit 315b, respectively.

  The first addition unit 315a adds the correction signal R11 ′ output from the level adjustment unit 313 to the luminance signal L11 output from the first delay unit 314a, and adds the luminance signal L11 ′ added to the correction signal R11 ′. The image is output to the composite image generation unit 311. The second addition unit 315b adds the correction signal R12 ′ output from the level adjustment unit 313 to the luminance signal L12 output from the second delay unit 314b, and adds the luminance signal L12 ′ added to the correction signal R12 ′. The image is output to the composite image generation unit 311. The composite image generation unit 311 generates an image in which the first and second images related to the luminance signal L11 ′ and the luminance signal L12 ′ output from the first addition unit 315a and the second addition unit 315b are adjacent in the horizontal direction. The luminance signal L ′ of the generated image is output to the display unit 24 and the video codec unit 25.

  The level adjustment unit 313 includes the same counter 313a, position selection unit 313b, weight processing unit 313c, first multiplication unit 313d, second multiplication unit 313e, and third multiplication unit 313j as in the first embodiment. The second multiplication unit 313e multiplies the correction signal R11 output from the first correction signal generation unit 312a by the level adjustment signal m ′ output from the first multiplication unit 313d, and the correction signal obtained by multiplying the level adjustment signal m ′. R11 ′ is output to the first adder 315a. The third multiplication unit 313j multiplies the correction signal R12 output from the second correction signal generation unit 312b by the level adjustment signal m ′ output from the first multiplication unit 313d, and multiplies the level adjustment signal m ′. R12 ′ is output to the second adder 315b.

  As in the modification of the first embodiment, the control unit 28 stores the first parameter p1 corresponding to the pixel position at the right end of the image and the second parameter p2 corresponding to the position of the pixel at the left end in the memory. The first and second parameters p1 and p2 related to the edge of the image are output to the position selection unit 313b to control the position selection unit 313b.

  The other configurations, operations, and effects of the image quality correction apparatus 301 according to the fourth embodiment are the same as the configurations, functions, and effects of the image quality correction apparatus according to the first embodiment. A detailed description thereof will be omitted.

  The image quality correction apparatus 301 configured as described above is synthesized to improve the sharpness of the image while suppressing the glare of the image at the edge of the input image and to combine the image whose image quality is corrected. It is possible to generate an image with high sharpness in which glare of the image at both ends and boundary portions of the image is suppressed.

  In addition, since the first image and the second image that are input are subjected to image quality correction in parallel, for example, an image captured by an imaging device, an image input from an external computer, or an image reproduced from a recording medium Any two of them can be subjected to high-speed image quality correction, and the image quality-corrected images can be combined.

It is a block diagram which shows the structure of an imaging device provided with the image quality correction apparatus which concerns on Embodiment 1 of this invention. 1 is a block diagram illustrating a configuration of an image quality correction apparatus according to Embodiment 1. FIG. 3 is a timing chart illustrating an operation of the image quality correction apparatus according to the first embodiment. Schematic diagram showing the luminance signal of the synthesized image, the correction signal generated based on the luminance signal, the level adjustment signal for adjusting the level of the correction signal, and the correction signal level-adjusted by the level adjustment means. It is. 6 is a timing chart illustrating an operation of the image quality correction apparatus according to the modification of the first embodiment. It is a block diagram which shows the structure of the image quality correction apparatus which concerns on Embodiment 2 of this invention. It is a timing chart which shows operation | movement of the image quality correction apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the image quality correction apparatus which concerns on Embodiment 3 of this invention. It is a block diagram which shows the structure of the image quality correction apparatus which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structure of the conventional image quality correction apparatus. It is a figure which shows the level change of the luminance signal in which the luminance signal in the horizontal line of the synthesized image which adjoined two to-be-combined images, the edge which concerns on a luminance signal, and the correction signal were added.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image quality correction apparatus 11 Composite image generation part 12 Correction signal generation part 13 Level adjustment means 13a Counter 13b Position selection part 13c Weight processing part 13d 1st multiplication part 13e 2nd multiplication part 14 Delay part 15 Addition part 20a Lens 20b Image sensor 21 Synchronization signal generation unit 22 Imaging signal processing unit 23 Image processing unit 24 Display unit 25 Video codec unit 26 Recording / playback unit 28 Control unit

Claims (9)

A correction signal generating unit configured to generate a correction signal for correcting the luminance signal so as to emphasize an edge related to a spatial change in the level of the luminance signal based on a luminance signal included in each pixel of the image; In the image quality correction apparatus that adjusts the level of the correction signal generated by the generation means and adds the correction signal to the luminance signal,
Level adjustment means for adjusting the level of the correction signal generated by the correction signal generation means according to the position of the pixel;
A first parameter and a second parameter corresponding to a predetermined pixel position, a level adjustment parameter for adjusting the level by multiplying the correction signal, and a weight parameter for weighting the level adjustment parameter according to the pixel position are stored. A controller having a memory and controlling the operation of the level adjusting means by outputting the first and second parameters, the level adjusting parameter and the weight parameter to the level adjusting means;
Adding means for adding the correction signal adjusted by said level adjustment means to said luminance signal
With
The level adjusting means includes
A counter that outputs a count value counted in synchronization with the horizontal synchronization signal and / or the vertical synchronization signal;
A position selection unit that compares the count value output from the counter and the first and second parameters output from the control unit and outputs a position parameter having a value corresponding to a relative position with respect to a predetermined pixel;
A weight processing unit that outputs a weight signal corresponding to the position parameter based on the position parameter output from the position selection unit and the weight parameter output from the control unit;
A first multiplication unit that multiplies the weight signal output from the weight processing unit and the level adjustment parameter output from the control unit, and outputs a level adjustment signal obtained by multiplication;
An image quality correction apparatus comprising: a second multiplication unit that multiplies the level adjustment signal output from the first multiplication unit and the correction signal generated by the correction signal generation unit . Comprising a generating means for generating a composite image in which a plurality of composite images are adjacent to each other;
The level adjusting means includes
When adjusting the correction signal for correcting the luminance signal of the synthesized image generated by the generating means, the level of the correction signal related to the pixel increases as the pixel is closer (far) from the boundary between the synthesized images ( 2. The image quality correction apparatus according to claim 1, wherein the image quality correction apparatus is reduced. The generating means includes
Generating a composite image in which a plurality of composite images are adjacent in the horizontal direction and / or the vertical direction;
The level adjusting means includes
3. The correction signal level is reduced by specifying the boundary portion based on a horizontal synchronization signal and / or a vertical synchronization signal, and reducing a level of the correction signal in a required pixel range including the specified boundary portion. The image quality correction device described in 1. The level adjusting means includes
4. The image quality correction apparatus according to claim 2, wherein the level of the correction signal is reduced at a symmetric reduction rate with respect to the boundary portion. S first image and the second image husband on the basis of a luminance signal having for each pixel, the first correction to generate a correction signal for correcting the luminance signal to emphasize the edge of the spatial variation of the level of the luminance signal and a signal generating unit and the second correction signal generation unit, the first correction signal generating unit and a correction signal to the level adjustment by the second correction signal generator is generated, so as to respectively added to the luminance signal according to the correction signal An image quality correction device
Level adjustment means for adjusting the level of each of the correction signals generated by the first correction signal generation unit and the second correction signal generation unit according to the position of the pixel;
A first parameter and a second parameter corresponding to a predetermined pixel position, a level adjustment parameter for adjusting the level by multiplying the correction signal, and a weight parameter for weighting the level adjustment parameter according to the pixel position are stored. A control unit having a memory and controlling the operation of the level adjustment unit by outputting the first and second parameters, the level adjustment parameter, and the weight parameter to the level adjustment unit;
A correction signal the level adjusting means is adjusted, adding means for respectively adding the luminance signal according to said correction signal,
A composite image generation unit that generates a composite image in which the first image and the second image each having a luminance signal for each pixel after the addition signal is added by the adding unit are adjacent
With
The level adjusting means includes
A counter that outputs a count value counted in synchronization with the horizontal synchronization signal and / or the vertical synchronization signal;
A position selection unit that compares the count value output from the counter and the first and second parameters output from the control unit and outputs a position parameter having a value corresponding to a relative position with respect to a predetermined pixel;
A weight processing unit that outputs a weight signal corresponding to the position parameter based on the position parameter output from the position selection unit and the weight parameter output from the control unit;
A first multiplication unit that multiplies the weight signal output from the weight processing unit and the level adjustment parameter output from the control unit, and outputs a level adjustment signal obtained by multiplication;
A second multiplier that multiplies the level adjustment signal output from the first multiplier and the correction signal generated by the first correction signal generator;
An image quality correction apparatus comprising: a third multiplication unit that multiplies the level adjustment signal output from the first multiplication unit and the correction signal generated by the second correction signal generation unit . The level adjusting means includes
6. The pixel according to any one of claims 1 to 5, wherein the level of the correction signal related to the pixel is increased (decreased) more greatly as the pixel is closer (far) from the edge of the image. Image quality correction device. The level adjusting means includes
7. The level of the correction signal is reduced in a predetermined pixel range including the specified end by specifying the end based on a horizontal sync signal and / or a vertical sync signal. The image quality correction device described in 1. The level adjusting means includes
7. When the level of the correction signal is reduced in each of a plurality of pixel ranges including the end portion, the level of the correction signal is reduced by a similar reduction rate in each pixel range. Alternatively, the image quality correction apparatus according to claim 7. An image sensor that captures one image as a plurality of divided images;
An image quality correction apparatus according to any one of claims 2 to 8,
The image quality correction device includes:
An image pickup apparatus, wherein image quality correction of an image picked up by the image pickup device is performed.

Images