JP4418482B2 - Detection device - Google Patents

Description

  The present invention relates to a technique used in an imaging apparatus, and more particularly to a technique used in an imaging apparatus that takes a subject image captured through a finder optical system by forming an image on the surface of an imaging element through the imaging optical system.

  There has been known a digital camera that includes a finder optical system and an imaging optical system, and shoots an object image captured through the finder optical system by forming an image on the surface of the imaging element through the imaging optical system. In such a camera, it is desirable that the range visually recognized in the field frame provided by the finder optical system and the range of the actually recorded image are infinite. Here, if (percentage in the field frame) / (range of the photographed image) is defined as a percentage, the field ratio is ideally 100%.

  However, in actuality, in the manufacturing process of the digital camera, a slight positional deviation occurs in the setting of the field frame and the image sensor. Therefore, in order to prevent the occurrence of a case where a part of the image in the field frame due to the positional deviation is not recorded, the field frame is set to a size that allows for the positional deviation in advance. It was. For this reason, the visual field ratio obtained with a digital camera using such a visual field frame has been limited to about 95% at most.

  In order to improve the field of view rate, a method of finely adjusting the positional relationship between the field frame and the image sensor in the manufacturing process of the digital camera can be considered. However, this method increases the manufacturing cost due to the position adjustment. In addition, when a CCD (Charge Coupled Device) is used as an image pickup device, for example, there is an accuracy error in the fixed position of the CCD device itself in the component package (about ± 0.15 mm), and the outer shape of the component package is the same. Since there is a degree of accuracy error, it is difficult to specify a reference position for position adjustment, and this adjustment is extremely difficult.

  In view of the above problems, it is an object of the present invention to easily provide a high-quality finder optical system capable of ensuring an ideal field of view.

A detection device according to one aspect of the present invention is attached to an imaging device having an imaging element that captures a subject image and performs photoelectric conversion, a single-lens reflex type finder optical system that observes the subject image, and the finder optical system. A detection apparatus in an imaging system including an adjustment camera and a detection apparatus, which corresponds to a shooting range indicated by the finder optical system, which is an area in a captured image captured by the imaging element. A detection unit that detects a position of the region; and an information generation unit that generates information for specifying the position detected by the detection unit in the captured image. The detection unit is attached to the finder optical system. Extraction means for extracting an image in an area within the shooting range as an image to be calculated from an image obtained by the adjustment camera thus obtained; Correlation calculation means for performing a correlation calculation between the partial image extracted from the image and the calculation target image, and the position of the partial image having the highest correlation with the calculation target image as a result of the correlation calculation by the correlation calculation means A partial image position detecting means for detecting, wherein the information generating means generates the information from the position of the partial image detected by the partial image position detecting means, and the extracting means is provided in the finder optical system. The image of the corner portion of the quadrangular field frame that defines the imaging range shown as above is extracted as the calculation target image, and the partial image position detection means is provided at at least one vertex in the partial image with respect to the image of the corner portion. The above-described problem is solved by configuring so that the position of the corresponding pixel is detected from the captured image .

  According to this configuration, the field of view of the finder optical system of the imaging device in the captured image is used as information indicating the position of the extraction when extracting a partial area of the captured image captured by the imaging device of the imaging device. Generates information indicating Therefore, by providing this information to the imaging device, the imaging device can extract an image of a region corresponding to the field of view from the captured image to obtain a recorded image. As a result, since the field of view of the finder optical system and the area included in the recorded image are matched, the field of view of the imaging apparatus is improved without making any complicated adjustments.

  Further, according to this configuration, it is possible to detect a partial image of an area corresponding to the shooting range indicated by the finder optical system of the imaging device from a captured image captured by the imaging device of the imaging device. By providing information that specifies the position of the partial image to the imaging device, it is possible to match the imaging range indicated by the finder optical system and the area included in the recorded image with the imaging device. Will improve.

  According to this configuration, since the size and shape of the region extracted from the captured image are limited in advance, the extraction can be performed if only the position of the region can be specified. Therefore, it is possible to reduce the information given to the imaging device in order to match the shooting range indicated by the finder optical system with the area included in the recorded image.

  In the detection device according to the present invention described above, the information generation unit generates information indicating an address of a memory included in the imaging device in which information about the pixels constituting the captured image is stored, and the address is obtained. Accordingly, the information may be configured to specify the position of the region.

  According to this configuration, if such information generated by the information generating unit is provided to the imaging device, the imaging device can obtain the information based on the address from the memory in which the pixel information of the captured image is stored. Since it is possible to extract an image of a partial region of the captured image simply by reading out the image, it is possible to reduce the processing burden for generating a recorded image in the imaging apparatus.

  In the detection device according to the present invention described above, receiving means for receiving a signal indicating a picked-up image picked up by an image pickup device included in the image pickup device, and information for specifying the position generated by the information generating means. Transmission means for transmitting to the imaging apparatus, and the detection means may be configured to detect the position of the region from the captured image received by the reception means.

  According to this configuration, it is possible to smoothly acquire a captured image captured by the imaging element included in the imaging apparatus and apply the information generated by the information generation unit to the imaging apparatus.

  As described above, according to the present invention, the position of the region corresponding to the shooting range indicated by the finder optical system of the imaging device is a region in the captured image captured by the imaging device of the imaging device. Is generated, and information for specifying the position from the captured image is generated, the imaging device extracts a part of the captured image captured by the imaging element based on the information, and the image of the region is used as a recorded image. Configure to generate.

  According to the above-described configuration of the present invention, the field of view of the finder optical system and the area included in the recorded image are matched, so that a finder optical system having a good field of view can be provided without complicated adjustment. The effect of becoming.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing the configuration of a system for carrying out the present invention. The system shown in the figure includes a digital camera 100, a video camera 200, and a personal computer (PC) 300, and this system is constructed by an inspection / adjustment process in the manufacturing process of the digital camera 100.

The digital camera 100 captures a subject and is a single-lens reflex camera capable of observing a subject image obtained through the photographing lens 111 with an optical viewfinder.
Hereinafter, the configuration of the digital camera 100 will be described.

The photographing lens 111 forms a subject image on the light receiving surface of the image sensor 131.
The shutter 112 adjusts the amount of light that has passed through the photographing lens 111 by changing the size of the opening.

The half mirror 113 divides the light that has passed through the shutter 112 into one that proceeds to the finder optical system and one that proceeds to the imaging optical system.
The field frame mask 114 is a hollow mask that superimposes a field frame that displays a range of images that can be captured by the digital camera 100 on an image observed with the optical viewfinder.

  The light traveling to the finder optical system passes through the field frame mask 114, then passes through the lens A 115, the course thereof is changed by the mirror 116, and further passes through the lens B 117. As a result, the object image is obtained in the video camera 200. Forms an image.

The system controller 121 has a CPU (Central Processing Unit) and controls the operation of the entire digital camera 100.
In the flash ROM 122, a control program for causing the CPU of the system controller 121 to control the operation of the entire digital camera 100 is recorded in advance. The CPU reads out the control program from the flash ROM 122 and executes it, thereby enabling control processing of the entire digital camera 100.

  The work memory 123 is a work memory required for the CPU of the system controller 121 to execute the control program stored in the flash ROM 122.

The switch (SW) unit 124 is a generic term for a group of switches that are operated by the user of the digital camera 100 to give various instructions to the digital camera 100.
The USB interface 125 provides an interface conforming to USB (Universal Serial Bus), which is one of the serial data transmission standards, and enables data exchange with other devices, as shown in FIG. In the configuration, data exchange with the personal computer 300 is controlled.

  The shutter control circuit 126 controls the degree of opening of the shutter 112 based on an instruction from the system controller 121. The image sensor 131 photoelectrically converts the subject image formed on the light receiving surface and outputs an analog signal indicating an image representing the subject image.

  The digital process circuit 132 removes reset noise and adjusts the signal level included in the analog signal output from the image sensor 131, and converts the analog signal after these processes into image data that is digital data. And convert. In addition, image correction processing such as gamma correction and white balance for an image expressed by image data, and expression by YC (luminance-color difference) component of image data expressed by luminance of three primary colors of RGB light. Also performs conversion processing.

  The frame memory 133 is used not only as a buffer memory for temporarily storing the image data output from the digital process circuit 132 but also as a working storage area for processing by the compression / decompression circuit 135. .

The image information display unit 134 has an LCD (Liquid Crystal Display), and performs reproduction display of captured images, display of various information, and the like.
The compression / decompression circuit 135 performs image data expansion processing and image data compression processing for recording / reproducing image data. In this embodiment, the compression / decompression circuit 135 performs image data expansion processing and image data compression processing in accordance with the JPEG (Joint Photographic Experts Group) method.

The card interface circuit 136 writes and reads data to and from the memory card 137.
The memory card 137 is a semiconductor recording medium that records image data, and is configured to be detachable from the digital camera 100.

The digital camera 100 is configured as described above.
The video camera 200 captures a subject image obtained through the finder optical system of the digital camera 100 and transmits the captured image to the PC 300.

  The PC 300 compares the image captured by the video camera 200 with the image formed on the surface of the image sensor 131 through the imaging optical system of the digital camera 100 and outputs the comparison result to the digital camera 100.

  The configuration of the PC 300 will be described. The CPU 301 that controls each component by executing the control program, the ROM 302 that stores the basic control program that causes the CPU 301 to control each component, and the CPU 301 when the CPU 301 executes the control program. A RAM 303 used as a work area, a video camera interface (I / F) 304 for acquiring a captured image sent from the video camera 200, and a hard disk device (HDD) 305 used as a storage area for a control program and various data described later. In addition, an interface conforming to the USB standard is provided so that data can be exchanged with other devices. In the configuration shown in FIG. 1, data exchange with the digital camera 100 is controlled. USB interface (I / F 306, CPU 301 is connected via a bus 307 that is managed is configured to allow exchange of data with each other by, and has a standard computer configuration.

Next, FIG. 2 will be described. FIG. 2 shows the principle configuration of the present invention.
2A, the digital camera 100 includes an image data transmission unit 101, an address reception unit 102, an address storage unit 103, and a recorded image generation unit 104. These components are realized by a control process performed by the system controller 121 by executing a control program stored in the flash ROM 122 in advance.

The image data transmission unit 101 transmits image data representing an image captured by the image sensor 131 to the PC 300.
The PC 300 receives the image data and compares the image represented by the image data with the subject image obtained through the finder optical system captured by the video camera 200 and limited in the field of view by the field frame mask 114. Find the number of relationships. Then, the position where the image data is cut out when the correlation coefficient is maximized is specified, and the address indicating the position (start address and end address) is transmitted to the digital camera 100.

The address receiving unit 102 receives this address transmitted from the PC 300.
The address storage unit 103 stores the address received by the address receiving unit 102.

  The recorded image generation unit 104 cuts out the image according to the address stored in the address storage unit 103 with respect to the image data representing the image picked up by the image pickup device 131, and shoots image data of the cut out image. Record as an image. The recorded image generation unit 104 performs the above-described operation every time a new image is taken by the user with the digital camera 100.

  In this manner, the digital camera 100 cuts out an image having the maximum correlation with the image of the finder optical system whose field of view is limited by the field frame mask 114 from the image picked up by the image sensor 131, and the cut out image Therefore, it is possible to bring the image of the finder optical system closer to the captured image without considering the outline of the component package of the CCD element and the accuracy error that may occur at the fixed position. The rate can be secured with this finder optical system.

  In the configuration of (A) described above, the start address and the final address are transmitted from the PC 300 as addresses indicating the cut-out position of the image data, and the address receiving unit 102 of the digital camera 100 receives the addresses and receives the address storage unit. I was trying to memorize in 103. Here, if the image to be recorded as a captured image is a quadrangle and the vertical and horizontal sizes are known, the known image size is stored in advance in the recorded image size storage unit 105 as shown in FIG. As a result, only one of the first address and the last address is transmitted from the PC 300 as an address indicating the cutout position of the image data, and the address receiving unit 102 of the digital camera 100 receives the address. Even if it is stored in the address storage unit 103, the recorded image generation unit 104 can cut out the image for the image data representing the image captured by the image sensor 131, and the image is transmitted from the PC 300 to the digital camera 100. The amount of information is reduced.

  Next, FIG. 3 will be described. This figure is a flowchart showing the processing contents of the address setting processing. The address setting process is a process for obtaining an address indicating the cutout position of the image data described above.

  3A is a process performed by the system controller 121 of the digital camera 100, and FIG. 3B is a process performed by the CPU 301 of the PC 300.

  First, (A) will be described. This process is performed by the system controller 121 by reading and executing the control program stored in the flash ROM 122, and is started when an instruction to start the address setting process is input from the SW unit 124 or the like.

First, in S 101, image data representing an image captured by the image sensor 13 is acquired from the digital process circuit 132 and temporarily stored in the frame memory 133.
In S102, the digital process circuit 132 performs processing for converting the representation format of the image data stored in the frame memory 133 from the luminance of the three primary colors of RGB light to that of the YC component. The image data represented by the YC component is temporarily stored in the frame memory 133.

The usage status of the frame memory 133 is shown in FIG.
The image data acquired from the digital process circuit 132 by the process of S101 described above is first stored in the “IS Bayer Buffer” area in the frame memory 133 as so-called RGB Bayer data. Thereafter, the image data is converted into one expressed by the YC component by the process of S102, and the converted data is stored in the “YC Buffer” area. The image data expressed by the YC component (YCbCr) is then subjected to image data compression processing by the JPEG method in the compression / decompression circuit 135, and a video signal for displaying an image on the image information display unit 134 is displayed. Also used for generation.

  In S103, only the Y (luminance) component data in the image data represented by the YC component stored in the frame memory 133 by the processing in the previous step is extracted, and the process of transmitting this Y component data to the PC 300 is performed by USB. Let the interface 125 do this.

In S <b> 104, the USB interface 125 is caused to receive the address sent from the PC 300 for specifying the above-described image cutout position.
In S <b> 105, processing for storing the address received by the USB interface 125 in the flash ROM 122 is performed.

  After the completion of this process, the process of FIG. 3A is completed, the setting of the address for specifying the image cutout position for the digital camera 100 is completed, and the digital camera 100 is shipped to the distribution market. Is done.

  Next, (B) will be described. This process is performed by the CPU 301 by reading and executing the control program stored in the HDD 305, and is started when an instruction to start the address setting process is given to the PC 300.

  First, in step S <b> 201, the video camera I / F 304 performs processing for acquiring image data (finder image data) representing a subject image obtained through the finder optical system of the digital camera 100 sent from the video camera 200.

  In S202, a partial image of a portion adjacent to the field frame formed by the field frame mask 114 is cut out from the image (finder image) expressed by the finder image data acquired by the process of the previous step.

  The process of S202 will be described with reference to FIG. 5A. In the process of S202, the upper left partial image adjacent to the field frame in the finder image, which is “A” in FIG. The partial image in the lower right part, which is “B” in the figure, is cut out. These images are referred to as “images in the mask adjacent area”.

  In S203, the USB I / F 306 is caused to acquire the image data of only the Y component sent from the digital camera 100 by the process of S103 described above. The image represented by this image data is an image obtained through the imaging optical system, and the action of the field frame mask 114 can provide a wider range than the viewfinder image as shown in FIG. 5B. It has become.

In S204, a correlation calculation is performed on the image in the mask adjacent area.
The correlation calculation performed by the process of S204 is performed in two directions of the captured image in the horizontal direction and the vertical direction.

  First, as shown in FIG. 5C, a partial image having the same area as that of the mask adjacent area A is extracted from the photographed image while being shifted by one pixel unit in the vertical direction, and the extracted partial image and the mask adjacent area A are extracted. The correlation coefficient with the image is calculated. When the correlation coefficient is maximized, that is, when the correlation between the extracted partial image and the image of the mask adjacent area A is maximized, the vertical position of the uppermost pixel of the extracted partial image is determined. get.

  Next, as shown in FIG. 5D, a partial image having the same area as the mask adjacent area A is extracted from the photographed image while being shifted by one pixel unit in the horizontal direction, and the extracted partial image and the mask adjacent area A are extracted. The correlation coefficient with the image is calculated. Then, when this correlation coefficient is maximized, that is, when the correlation between the extracted partial image and the image of the mask adjacent area A is maximized, the horizontal position of the leftmost pixel of the extracted partial image is determined. get.

  Based on the address information about the “YCBBuffer” area of the frame memory 133 prepared in advance on the PC 300 side, the pixel located at the intersection of the vertical position and the horizontal position obtained as described above is used. The address where the data is stored is determined. The address obtained in this way becomes the head address for specifying the cutout position of the image data.

  Next, the position of the partial image that maximizes the correlation coefficient with respect to the mask adjacent area B is similarly determined from the captured image, and in the “YC Buffer” area of the frame memory 133, the lower right pixel in the determined partial image. The address at which the data is stored is obtained, and the address thus obtained is the final address for specifying the cut-out position of the image data.

Note that it is preferable that the subject image at this time has a somewhat complicated pattern because the maximum point of the correlation coefficient can be clearly detected.
In S <b> 205 of FIG. 3B, the USB I / F 306 is caused to perform processing for transmitting the start address and the final address obtained as described above to the digital camera 100. Data indicating these addresses is stored in the flash ROM 122 by the processing of S104 and S105 in FIG.

  After the completion of this process, the process of FIG. 3B ends, the setting of the address for specifying the above-described image cutout position for the digital camera 100 is completed, and the digital camera 100 is shipped to the distribution market. Is done.

  After that, when shooting with the digital camera 100 is performed, the system controller 121 sets the two pixels specified by the first address and the last address in the image data stored in the “YC Buffer” area of the frame memory 133. The compression / decompression circuit 135 is made to read only the data representing the image included in the quadrangle whose position on the image is the diagonal vertex, and the image data created by these data is stored in the memory card 137. Try to record. By doing so, an ideal view rate is ensured by the finder optical system of the digital camera 100.

  As shown in FIG. 2B, if the shape and size of the recorded image are set in advance and the setting contents are shown in the flash memory 122 or the like, the correlation calculation is performed on the mask adjacent area A or B. Only one of the first address and the last address is transmitted from the PC 300 as an address indicating the cut-out position of the image data, and the digital camera 100 receives the address and receives the flash ROM 122. The image can be cut out from the image data representing the image picked up by the image pickup device 131 even if it is stored in the image pickup device 131. For this purpose, among the image data stored in the “YC Buffer” area of the frame memory 133, the pixel specified by the start address or the final address is used as a vertex, and the shape is specified by the image size. It is only necessary to cause the compression / decompression circuit 135 to read only data relating to what represents the image to be displayed.

  In addition, as shown in FIG. 6, it is advantageous that the vertical and horizontal sizes of the opening portion of the field frame mask 114 are values obtained by multiplying the cell size of the CCD unit used as the image sensor 131 by a multiple of 8. This is because in the JPEG method, compression is performed in units of 8 × 8 blocks, so by setting the field frame mask 114 to this size, the range in the field frame and the range of the recorded image after JPEG expansion processing are in pixel units. This is because it is possible to make them coincide with each other and it is possible to secure a field of view rate of 100%.

  Note that a control program for causing the computer to execute the processing shown in the flowchart of FIG. 3B can be read by a computer such as a flexible disk, an MO (magneto-optical disk), a CD-ROM, a DVD-ROM, or the like. The present invention can also be implemented on a computer by recording the program on a recording medium, causing the computer to read the program from the recording medium and executing the program. Further, such a recording medium may be a storage device provided in a program server system connected to a computer via a communication network. In this case, the transmission signal obtained by modulating the carrier wave with the data signal representing the control program is transmitted from the program server system through the communication network, and the computer demodulates the received transmission signal and reproduces the control program. By doing so, the control program can be executed.

  In addition, the present invention is not limited to the above-described embodiments, and various improvements and changes can be made.

It is a figure which shows the structure of the system which implements this invention. It is a figure which shows the principle structure of this invention. It is a flowchart which shows the processing content of an address setting process. It is a figure which shows the utilization condition of a frame memory. It is a figure explaining the process performed by PC. It is a figure which shows the example of preparation of a visual field frame mask.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Digital camera 101 Image data transmission part 102 Address receiving part 103 Address memory | storage part 104 Recorded image generation part 105 Recorded image size memory | storage part 111 Shooting lens 112 Shutter 113 Half mirror 114 Field frame mask 115 Lens A
116 Mirror 117 Lens B
121 System controller 122 Flash ROM
123 Work memory 124 Switch unit 125, 306 USB interface 126 Shutter control circuit 131 Image sensor 132 Digital process circuit 133 Frame memory 134 Image information display unit 135 Compression / decompression circuit 136 Card interface circuit 137 Memory card 200 Video camera 300 Personal computer 301 CPU
302 ROM
303 RAM
304 Video camera interface 305 Hard disk device 307 Bus

Claims (3)

An imaging device including an imaging device that captures a subject image and performs photoelectric conversion, an imaging device having a single-lens reflex type finder optical system for observing the subject image, an adjustment camera attached to the finder optical system, and a detection device A detection device in the system,
Detecting means for detecting a position of an area in a captured image captured by the imaging element and corresponding to an imaging range indicated by the finder optical system;
Information generating means for generating information for specifying the position detected by the detecting means in the captured image;
The detection means includes
Extraction means for extracting an image of an area within the photographing range as an operation target image from an image obtained by an adjustment camera attached to the finder optical system;
Correlation calculation means for performing correlation calculation between the partial image extracted from the captured image and the calculation target image;
As a result of the correlation calculation by the correlation calculation means, it has a partial image position detection means for detecting the position of the partial image having the highest correlation with the calculation target image,
The information generation means generates the information from the position of the partial image detected by the partial image position detection means ,
The extraction means extracts, as the calculation target image, an image of a corner portion of a rectangular field frame that defines a photographing range indicated by the finder optical system,
The partial image position detecting means detects, from the captured image, a pixel position corresponding to at least one vertex in the partial image with respect to the image of the corner portion;
A detection device characterized by that. The information generation unit generates information indicating an address of a memory included in the imaging device in which information about the pixels constituting the captured image is stored, and information for specifying the position of the region using the address; The detection device according to claim 1, wherein: Receiving means for receiving a signal indicating a picked-up image picked up by an image pickup device of the image pickup device;
Transmission means for transmitting information specifying the position generated by the information generation means to the imaging device;
The detecting means detects a position of the region from a captured image received by the receiving means;
The detection apparatus according to claim 1 or 2 , wherein

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