JP2007142908A - Imaging device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device for acquiring not only an image with a necessary aspect ratio but a high quality image, by utilizing effectively pixel information obtained at the photographing time even if the necessary image size is small. <P>SOLUTION: Image data of an object are read out by pixel addition from an image element. After image data of image size (b) is acquired as scale-downed from the effective pixel size (a) of the imaging element, surplus of predetermined width in upper/lower sides or in upper/lower and right/left sides is deleted from the image based on the image data to generate an image with a predetermined aspect ratio (c). Through the adjustment of surplus deleted from the image based on the image data read from the imaging element, the image with necessary aspect ratio can be generated. Even if the necessary image size is small, the discarded information amount at the image information obtained at the photography time can be reduced to a minimum. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus such as a digital camera and an imaging method thereof.

2. Description of the Related Art Conventionally, in an electronic camera device that records a captured image as image data on a recording medium, an image having a wide aspect ratio (9:16 or the like) that is different from a normal aspect ratio (3: 4), for example, is wider than usual. In the case of recording, there is known a method of generating and recording wide aspect ratio image data by deleting upper and lower surplus portions in normal aspect ratio image data output from an image sensor (for example, the following patent document). 1).
Japanese Patent Laid-Open No. 7-30788

  However, when an image with a wide aspect ratio is obtained by the above method, if the required number of pixels (image size) is considerably smaller than the number of effective pixels of the image sensor, the upper and lower sides of the image data output from the image sensor It is not sufficient to obtain the required number of pixels simply by cutting the surplus portion. Therefore, in the above case, it is necessary not only to cut the surplus part but also to perform pixel thinning (simple thinning) on the image data, resulting in image degradation such as generation of false colors. There was a problem that.

  The present invention has been made in view of such a conventional problem. In addition to obtaining an image having a required aspect ratio, pixel information obtained at the time of imaging can be obtained even when the required image size is small. An object of the present invention is to provide an imaging apparatus and an imaging method capable of obtaining a high-quality image that is effectively used, and a program used for realizing them.

  In order to solve the above-mentioned problem, in the invention of claim 1, in an imaging apparatus including an imaging device for imaging a subject image, a reading unit that reads out image data of the subject image from the imaging device by adding pixels And an image generation means for generating an image having a predetermined aspect ratio by deleting an excess portion having a predetermined width along a predetermined side of the image from the image based on the image data read by the reading means. It was assumed.

  In such a configuration, the image data of the subject image is read out from the image sensor in a state where the image data is reduced by pixel addition and almost all or all of the effective pixels are reflected, and a predetermined image in the image based on the image data is read. By deleting an excess portion having a predetermined width along the side, an image having a predetermined aspect ratio is generated. Therefore, it is possible to generate an image with the required aspect ratio by adjusting the surplus portion to be deleted from the image based on the image data read from the image sensor, and even when the required image size is small, it was obtained at the time of imaging. The amount of information discarded from all pixel information can be minimized.

  According to a second aspect of the present invention, the image generation means deletes an excess portion having a predetermined width at the top and bottom and / or right and left of the image from the image based on the image data read by the reading means. Thus, an image having a predetermined aspect ratio is generated.

  According to a third aspect of the present invention, the image generating means generates an image having a predetermined aspect ratio different from the aspect ratio of the effective pixel area in the image sensor.

  According to a fourth aspect of the present invention, the image generation means generates an image having a plurality of types of aspect ratios different from the aspect ratio of the effective pixel area in the image sensor.

  According to a fifth aspect of the present invention, in addition to the image having a predetermined aspect ratio different from the aspect ratio of the effective pixel area in the image sensor, the image generation means has the same aspect as the effective pixel area in the image sensor. A ratio image was generated.

  In the invention according to claim 6, the image generation means obtains a plurality of types of images having different aspect ratios from images based on image data having the same number of added pixels read by the reading means. It was supposed to be generated.

  In the invention of claim 7, the pixel addition number when the image data is read from the image sensor by the reading unit is controlled to a pixel addition number corresponding to the size of the image generated by the image generation unit. It is assumed that a reading control means is provided.

  In such a configuration, the pixel addition number when reading image data from the image sensor can be set to a pixel addition number suitable for the required image size, which is also discarded from all pixel information obtained at the time of imaging. The amount of information required can be minimized.

  In addition, in the invention of claim 8, the reading means reads out the image data of the subject image from the image sensor as a reading mode for reading out the image data by adding pixels to the pixel addition mode, and the image data And a normal mode for reading out the image without performing pixel addition, and the readout control unit controls the readout mode in the readout unit to the pixel addition mode or the normal mode according to the size of the image generated by the image generation unit In addition, the pixel addition number in the image data read by the reading unit is controlled to be a pixel addition number corresponding to the size of the image generated by the image generation unit.

  According to a ninth aspect of the present invention, there is provided compression means for compressing the image data generated by the image generation means, and recording means for recording the compressed image data compressed by the compression means. And the compression means has a data processing capability according to the number of pixels of the image generated by the image generation means.

  In such a configuration, it is possible to improve processing efficiency when recording a captured image.

  According to a tenth aspect of the present invention, the image generating means is an image having a predetermined aspect ratio constituting a moving image from an image based on the image data read from the imaging element by the reading means at a constant period. Was supposed to be generated.

  In such a configuration, when generating a moving image having a predetermined aspect ratio, even if the required moving image size is small, the information amount to be discarded from all pixel information obtained at the time of imaging is minimized. It can be stopped to the limit.

  In the invention of claim 11, the recording means records a still image generated by the image generation means during still image shooting and a moving image generated by the image generation means during moving image shooting. The readout control means includes a pixel addition number including a pixel addition number in the image data read out by the reading means during the still image shooting, which is smaller than a pixel addition number in the image data read out by the reading means during the moving image shooting. The number was to be controlled.

  According to a twelfth aspect of the present invention, in the imaging method of an imaging apparatus including an imaging device for imaging a subject image, a step of reading out image data of the subject image from the imaging device by adding pixels, and reading Generating an image having a predetermined aspect ratio by deleting an excess portion having a predetermined width along a predetermined side of the image from the image based on the image data.

  In this method, the image data of the subject image is read out from the image sensor in a state where the image data is reduced by pixel addition and substantially all or all of the effective pixels are reflected, and a predetermined image in the image based on the image data is read. By deleting an excess portion having a predetermined width along the side, an image having a predetermined aspect ratio is generated. Therefore, it is possible to generate an image with the required aspect ratio by adjusting the surplus portion to be deleted from the image based on the image data read from the image sensor, and even when the required image size is small, it was obtained at the time of imaging. The amount of information discarded from all pixel information can be minimized.

  According to a thirteenth aspect of the present invention, there is provided a process for adding image data of the subject image from the image sensor and reading out the image data of the subject image from the image sensor to a computer having an image sensor that captures the subject image. A program that executes processing for generating an image having a predetermined aspect ratio by deleting an excess portion having a predetermined width along a predetermined side of the image from the image based on the read image data.

  As described above, in the present invention, an image having the required aspect ratio can be generated by adjusting the surplus portion to be deleted from the image based on the image data read from the image sensor, and the required image size is small. In addition, it is possible to minimize the amount of information discarded from all pixel information obtained at the time of imaging. Therefore, not only can an image with the required aspect ratio be acquired, but even when the required image size is small, it is possible to obtain a high-quality image that effectively uses the pixel information obtained at the time of imaging. .

  In addition, it is possible to generate an image having the same aspect ratio as the effective pixel region in the image sensor, a plurality of aspect ratio images not including the aspect ratio, and a plurality of aspect ratio images including the aspect ratio.

  In addition, the pixel addition number when reading image data from the image sensor can be set to a pixel addition number suitable for the required image size, thereby reducing the amount of information discarded in the pixel information obtained at the time of imaging. It can be minimized.

  Further, it is possible to improve the processing efficiency when recording the captured image.

  In addition, when generating a moving image having a predetermined aspect ratio, the amount of information discarded in the pixel information obtained at the time of imaging can be minimized even when the required moving image size is small. .

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a digital camera according to the present invention. This digital camera has a still image shooting function and a moving image shooting function, and has the following configuration.

  That is, the digital camera includes a camera body 1 and a recording medium 20 that can be attached to and detached from the camera body 1. The camera body 1 includes an optical system 2 including a zoom lens and a focus lens, and a CCD 3 that is an imaging unit. Has been. The CCD 3 is driven by horizontal and vertical drive signals sent from the timing generator 7 and photoelectrically converts the light image of the subject and outputs it as an imaging signal. In the present embodiment, the timing generator 7 functions as a reading unit of the present invention together with the CPU 13.

  The output signal of the CCD 3 is subjected to correlated double sampling and gain adjustment by the CDS circuit 4 and converted to a digital signal by the A / D conversion circuit 5. The A / D converted image signal is input to the DSP unit 6 and subjected to processing such as pedestal clamping. Then, the luminance / color difference matrix circuit in the block performs YUV conversion to obtain a luminance (Y) signal and a color difference (UV) signal. Is converted to Note that the DSP unit 6 also performs processing for improving image quality such as auto iris, auto white balance, and edge enhancement.

  The YUV data converted by the DSP unit 6 is sequentially stored in the built-in memory 14 (for example, SDRAM) for one frame. One frame of YUV data stored in the built-in memory 14 is subjected to size adjustment described later by the CPU 13 and then sent to the display controller 11, where it is converted into a video signal and passed through the LCD (liquid crystal display) 12. It is displayed as an image, that is, a moving image.

  Further, the digital camera has a JPEG compression / decompression block 8 and an MPEG compression / decompression block 9 which are the compression means of the present invention, and stores one frame stored in the built-in memory 14 when taking a still image in the recording mode. The YUV data is subjected to a size adjustment process, which will be described later, if necessary, and after being compressed by the JPEG compression / decompression block 8 according to the JPEG method or the like, coded into a file in the built-in memory 14, the media controller 10 is And recorded as still image data (still image file) on the recording medium 20 (recording means).

  In addition, one frame of YUV data stored in the built-in memory 14 during moving image shooting in the recording mode is adjusted in size by the CPU 13 as will be described later, and is sequentially sent to the MPEG compression / decompression block 9, and is encoded by the MPEG codec. The data is compressed and then encoded, and sequentially written into the recording medium 20 as frame data via the media controller 10. That is, stream recording is performed. Finally, it is recorded on the recording medium 20 as a moving image file. Note that the frame rate at the time of moving image shooting is determined by the timing signal generated by the timing generator 7, and the compression rate of the encoded data is determined by the quantization table value in the MPEG compression / decompression block 9. In the present embodiment, the maximum number of pixels that can be processed by the MPEG compression / decompression block 9 is the number of pixels (approximately 300,000 pixels) corresponding to the VGA image (480 × 640).

  On the other hand, in the playback mode, the JPEG compression / decompression block 8 decompresses the compressed data of the still image read from the recording medium 20 and expands it in the built-in memory 14 as still image data. Also, the MPEG compression / decompression block 9 expands the compressed data of the moving image read from the recording medium 20 and expands it in the built-in memory 14 as moving image data. The developed image is sent to the display controller 11 where it is converted into a video signal and then displayed on the LCD 12 as a reproduced image. The LCD 12 displays not only a through image and a reproduced image, but also a menu screen and a setting screen for selecting and setting various functions in the digital camera as necessary. The resolution of the LCD 12 is 540 pixels long and 720 pixels wide.

  The voice processing block 15 converts voice input to the microphone 16 built in the camera body 1 into a digital signal at the time of moving image shooting, and sends it to the built-in memory 14 as audio data after data compression. The audio data sent to the built-in memory 14 is sequentially written to the recording medium 20 as stream data together with the moving image frame data. The audio processing block 15 decodes the audio data sent from the built-in memory 14 and converts it into an analog audio signal, and then outputs the sound from the built-in speaker 17 built in the camera body 1 when reproducing the moving image.

  The key input block 18 displays a power key, a mode switching key, a shutter key used for shooting instructions during still image shooting, a recording instruction key used for recording start / end instructions during moving image shooting, and various setting screens. And a plurality of operation keys such as a set key used for a setting operation on the setting screen, and outputs a key input signal corresponding to the key operation by the user to the CPU 13.

  Each block described above is controlled by the CPU 13, and programs and various data necessary for the CPU 13 to control each block are stored in a program memory 19 which is a rewritable nonvolatile memory such as an EEPROM or a flash memory. . The program memory 19 also stores other setting data relating to the system and each function set or changed by the user. The CPU 13 functions as an image generation unit and a read control unit of the present invention by operating based on the program and key input signals.

  The program memory 19 stores setting information 100 shown in FIG. 2 used in operation in a recording mode to be described later. As shown in the figure, the setting information 100 includes a recording image size, a CCD driving mode corresponding to each size, that is, a driving mode for reading a pixel signal (Bayer data) from the CCD 3, and cuts of upper and lower and / or left and right excess portions. Information indicating the width.

  In the present embodiment, the aspect ratio of the CCD 3 is 3: 4 and the number of effective pixels is about 1.55 million pixels, and the recordable image size that can be set is the same as that used for still image shooting (the same as the aspect ratio of the CCD 3). ) Aspect ratio, that is, a plurality of types with the maximum aspect ratio (3: 4) “1,080 × 1,440” and a plurality of types with a maximum aspect ratio of “810 × 1440” (9:16) There are two types of aspect ratios for each resolution level of “high / medium / low”. In moving image shooting, there are two types: “480 × 640” with an aspect ratio of normal (3: 4) and “405 × 720” with an aspect ratio of landscape (9:16).

  Also, there are two types of CCD drive modes, a normal mode (non-pixel addition) and a pixel addition mode. The normal mode is a drive mode in which signal charges of all the pixels are read as they are by general frame reading from the CCD 3. The addition mode is a drive mode in which pixel signals are read from the CCD 3 by adding two pixels (four pixel addition) in the vertical direction and the horizontal direction.

  Here, a method of reading an image signal in the pixel addition mode (hereinafter referred to as a 4-pixel addition mode) will be described. FIG. 3 is a schematic diagram of the CCD 3 showing its principle. That is, the CCD 3 includes a number of photosensitive CCDs (R, G, and B in the figure) constituting pixels, a hold accumulation unit HOLD composed of CCDs that do not have a photosensitive function arranged in the horizontal direction, and a horizontal transfer unit 61. A vertical transfer unit (not shown) for vertically transferring the signal charge of the photosensitive CCD and an output circuit 62 are provided.

  The four-pixel addition mode in the present embodiment is a mode in which signal charges for one frame are read out in 4/8 lines and two fields as shown in the figure. In the first field, (15, 13, 11,...) Are vertically transferred, and at that time, the signal charge for one line is temporarily held for the transfer time of one line by using the hold accumulation unit HOLD, thereby adjoining each other. The signal charges of the odd lines are added, that is, the signal charges of two pixels of the same color are vertically added and transferred to the horizontal transfer unit 61. At the same time, the signal charges vertically added in the horizontal transfer unit 61 are transferred for two pixels. Then, the vertically added signal charges are added (horizontal addition) in a state shifted by two pixels in the horizontal direction. Thereafter, signal charges for two lines composed of the same color pixel array (R, G, R, G,...) Are vertically added, and signals of two pixels of the same color existing on the same line every other pixel. The signals of odd lines to which charges are horizontally added are read out, and then the signal charges of all odd lines are read in order.

  Similarly, in the second field, vertical and horizontal additions similar to those in the first field are performed on the even-numbered lines (16, 14, 12,...) In the vertical direction, and the same color pixel array (G , B, G, B,...) Are added vertically, and signal charges of two pixels of the same color existing every other pixel on the same line are added horizontally. The signal is read, and thereafter, the signal charges of all even lines are read in order.

  FIG. 4 is a conceptual diagram showing Bayer data composed of the imaging signals read out as described above. As shown in the figure, in the 4-pixel addition mode, the number of pixels in the vertical direction and the horizontal direction is each ½. Thus, Bayer data reflecting the pixel information of all pixels is obtained. FIG. 4 shows the positional relationship between the pixels (R, G, B) obtained by the vertical addition and the horizontal addition described above and the pixels that cannot be obtained. Bayer data consisting only of G, B) is acquired. Further, the R, G, and B pixel positions after addition of the four pixels shown in the figure are the center of gravity of the original four pixels to be added.

  Next, an operation according to the present invention of the digital camera having the above configuration will be described. 5 and 6 are flowcharts showing the contents of processing executed by the CPU 13 when the recording (photographing) mode is set by the user's mode switching key operation.

  As shown in FIG. 5, in the recording mode, the CPU 13 first sets the aspect ratio of the recorded image (still image or moving image) recorded in the recording mode and the recorded image size for the still image (step S1). . Here, for example, the contents recorded together with other setting data in a predetermined area of the program memory 19 and set at the end of the previous recording mode are set as initial values. The recorded image size of the moving image is uniquely determined according to the aspect ratio because there is only one settable size in each aspect ratio.

  Next, after the 4-pixel addition mode is set as the drive mode of the CCD 3 (step S2), the through image capturing at a predetermined slew rate (for example, 25 frames / second) is started (step S3). Image data is read out (step S4). Here, when the aspect ratio set at that time is “3: 4” (“3: 4” in step S5), the captured image after YUV conversion generated from the read imaging data (Bayer data), That is, for a captured image having a vertical and horizontal size of “540 × 720”, a size that cuts an end image with a width of 30 pixels, which is an excess part on the upper side and the lower side, and an end image with a width of 40 pixels on the left side and the right side. Adjustment is performed (step S6). Thereafter, the image after the size adjustment, that is, the image having the vertical and horizontal sizes of “480 × 640” is displayed on the LCD 12 as a through image (step S8). Note that the through image display in this case is a full screen display, and an image of “480 × 640” is enlarged to an image of “540 × 720” and used for display. However, if the size adjustment in step S6 is not performed, there is no need to enlarge.

  On the other hand, if the aspect ratio set at that time is “9:16” (“9:16” in step S5), the above-described YUV conversion after the YUV conversion generated from the read imaging data (Bayer data) is performed. With respect to the image of the vertical and horizontal sizes, the size adjustment is performed so as to cut the 68-pixel wide end image on the upper side and the 67-pixel wide end image on the lower side (step S7). Thereafter, the image after the size adjustment, that is, the image having the vertical and horizontal size of “405 × 720” is displayed on the LCD 12 as a through image (step S8). In the through image display in this case, the upper and lower display areas corresponding to the cut end image are filled with black.

  FIG. 7 shows the vertical direction in the effective pixel area (a) of the CCD 3, the imaging data (Bayer data) (b) read in the above-described 4-pixel addition mode, and the image (c) after the size adjustment in step S7 described above. It is the figure which showed the relationship between the number of pixels of a direction and a horizontal direction, and the part shown with the oblique line in FIG.7 (c) is an end image finally cut.

  Thereafter, the operation of changing the aspect ratio by the user, the operation of changing the recorded image size for the still image, the operation of the shutter key and the recording instruction key (steps S9, S11, S13, and S14 are all NO), the process returns to step S3. The through image display by the series of processes described above is repeated.

  In addition, while the through image is displayed as described above, the user can change the aspect ratio of the recorded image and the recorded image size for the still image by specifying the resolution level described above by a predetermined key operation. If the user has changed the aspect ratio (YES in step S9), the setting of the aspect ratio is changed at that time (step S10). If there is an operation for changing the recorded image size for the still image (YES in step S11), the setting content of the recorded image size for the still image at that time is changed according to the designated resolution level (step S12). ). That is, for example, when the aspect ratio is set to “3: 4”, the recording image size is changed to any one of “1,080 × 1,440”, “540 × 720”, and “480 × 640”. .

  If the shutter key is pressed while displaying a through image (YES in step S13), the process proceeds to the still image shooting process in step S23 and subsequent steps in FIG. 6 and the recording instruction key is pressed. In this case (YES in step S14), the process proceeds to the moving image shooting process in step S15 and subsequent steps in FIG. First, the moving image shooting process will be described. In that case, the imaging interval by the CCD 3 is first changed to a predetermined frame rate (for example, 30 frames / second), and imaging at a timing according to the changed frame rate is started. (Step S15).

  Then, the readout of the imaging data in the 4-pixel addition mode is performed as in the case of the through image display, and the readout imaging data (Bayer data) is YUV converted (step S16). Subsequently, the aspect ratio set at that time is confirmed, and if the aspect ratio “3: 4” (recorded image size is “480 × 640”) is set (“3: 4” in step S17). ), The upper, lower, left and right surplus portions of the captured image after YUV conversion, that is, the end images with a width of 30 pixels on the upper side and the lower side, respectively, and the end images with a width of 40 pixels on the left side and the right side are respectively cut. Frame data having a size of “480 × 640” is generated (step S18). When the aspect ratio “9:16” (the recording image size is “405 × 720”) is set (“9:16” in step S17), the upper and lower surplus portions of the captured image after YUV conversion In other words, the edge image having a width of 68 pixels on the upper side and the edge image having a width of 67 pixels on the lower side are respectively cut to generate frame data having a size of “405 × 720” shown in FIG. (Step S19). Thereafter, the frame data after the cut generated as described above is compressed in the MPEG compression / decompression block 9 and stream-recorded on the recording medium 20 (step S20).

  Thereafter, the processing of steps S15 to S20 described above is repeated until there is a shooting end instruction by the user's recording instruction key operation (NO in step S21). If there is a shooting end instruction, predetermined management data is created at that time. Then, it is stream-recorded first and added to the frame data to complete the moving image file (step S22), thereby ending the moving image recording.

  On the other hand, in the still image shooting process in accordance with the shutter key operation, first, exposure for a predetermined time determined by AE control is started (step S23), and the drive mode of the CCD 3 corresponds to the set recording image size. The mode (normal mode or 4-pixel addition mode) is set (step S23). That is, if the recorded image size is “1,080 × 1,440” to “540 × 960”, the normal mode is set, and if “540 × 720” to “540 × 720”, the 4-pixel addition mode is set. . Subsequently, when exposure for a predetermined time is completed (YES in step S25), the imaging data in the set drive mode is read out, and the readout imaging data (Bayer data) is YUV converted (step S26).

  Then, the vertical and horizontal cut widths shown in the setting data 100 (FIG. 2) corresponding to the recording image size set at that time are all “0”, and the end of the image data after YUV conversion. If it is not necessary to cut the image (NO in step S27), it is compressed as still image data in the JPEG compression / decompression block 8, and the compressed data is recorded in the recording medium 20 (step S29). To end still image shooting.

  Also, if the edge image needs to be cut for the image data after YUV conversion (YES in step S27), the width shown in the setting data 100 (FIG. 2) corresponding to the recorded image size. Only the size of the image data after YUV conversion is adjusted by cutting up, down, up, down, left and right (step S28). For example, if the recorded image size is “810 × 1,440”, the end images having a width of 135 pixels on the upper side and the lower side are cut. If the recorded image size is “480 × 640”, the end images with a width of 30 pixels on the upper side and the lower side are respectively cut, and the end images with a width of 40 pixels on the left side and the right side are respectively cut.

  Thereafter, the size-adjusted image data is compressed as still image data in the JPEG compression / decompression block 8, and the compressed data is recorded on the recording medium 20 (step S29), thereby terminating still image shooting.

  As described above, in the present embodiment, during still image shooting or moving image shooting, the drive mode of the CCD 3 is set to the 4-pixel addition mode, and an excess portion having a predetermined width is cut from the top, bottom, top, bottom, left and right of the captured image. By doing so, it is possible to obtain an image having a smaller number of pixels than the effective number of pixels of the CCD 3 or an image having a different aspect ratio. That is, after reducing the size of the image data to a size suitable for the recorded image size in advance by pixel addition, the necessary aspect ratio and recording are obtained by cutting off the excess part from the top, bottom, top, bottom, left, and right of the captured image as necessary. Ensure image size.

  Therefore, even when the upper and lower or upper and lower and right and left surplus portions of the captured image are cut such that the recorded image size is “480 × 640” or “405 × 720”, the total pixel information obtained at the time of imaging is used. The amount of information that is discarded can be minimized. At the same time, image degradation such as generation of false colors does not occur when cutting excess portions and thinning pixels (simple thinning) on image data read from the CCD 3. As a result, not only can the image of the required aspect ratio be acquired, but even when the required image size is small, it is possible to obtain a high-quality image that effectively uses the pixel information obtained at the time of imaging. .

  In the present embodiment, when displaying a through image in a still image or moving image shooting standby state, the drive mode of the CCD 3 is set to the 4-pixel addition mode, and the captured image is vertically or vertically or horizontally and horizontally. Since an image having a required image size and aspect ratio is obtained by cutting an excess portion having a predetermined width, a high-quality image can be obtained for a through image.

  In the present embodiment, the pixel addition number when the image data is read out from the CCD 3 by adding pixels is 4 pixels, and before moving images are captured, the excess portion is cut from the top, bottom, top, bottom, left and right of the captured image. The pixel addition is such that the number of pixels (540 × 720 = 388,800 pixels) is equal to or larger than the maximum number of pixels (480 × 640 = 307,200 pixels) that can be processed by the MPEG compression / decompression block 9. Is a number. In other words, the MPEG compression / decompression block 9 has a data processing capability according to the number of pixels of the moving image to be generated. Therefore, a series of data processing such as generation, compression, and recording of frame data at the time of moving image shooting can be performed very efficiently.

  In the present embodiment, a case has been described in which the digital camera has a recording instruction key used for recording start / end instruction during moving image shooting, in addition to the shutter key used for shooting instruction during still image shooting. However, the present invention is not limited to this, and the digital camera has a still image shooting mode and a moving image shooting mode individually as recording modes. It may be configured to be able to perform both instructions. Even in this case, when a through image is displayed in either the still image shooting mode or the moving image shooting recording mode, the drive mode of the CCD 3 is set to the 4-pixel addition mode and the captured image is set as in the present embodiment. If a display image having a required size corresponding to the resolution of the LCD 12 is generated by cutting an excess portion having a predetermined width from the top, bottom, top, bottom, left, and right, a high-quality image can be obtained as a through image.

  In this embodiment, the aspect ratio of the image can be set to a horizontal aspect ratio (9:16) in addition to the normal aspect ratio (3: 4). The aspect ratio (for example, “9:18”) may be set. Further, the aspect ratio does not need to be horizontally long, and for example, a vertically long aspect ratio (4: 3, etc.) may be set. In this case, the size of the image data is preliminarily set to the recorded image size by pixel addition. After the image is reduced to a suitable size, excess portions on the left and right sides of the image may be cut. In addition to the normal aspect ratio, a plurality of types of aspect ratios may be selectively set, or only an aspect ratio different from the normal aspect ratio may be selectively set. Further, the aspect ratio may be only a predetermined aspect ratio.

  In the present embodiment, the effective number of pixels of the CCD 3 is about 150,000 pixels, the maximum recording image size that can be recorded during still image shooting is “1,080 × 1,440”, and pixel addition The mode is the 4-pixel addition mode in which pixel signals are read out by adding 2 pixels (4 pixel addition) in the vertical direction and the horizontal direction from the CCD 3, but the number of effective pixels of the CCD 3 and the pixel addition are described. The number of pixels to be added in the mode may be other than this. Further, the number of pixels to be added in the pixel addition mode may be other than 4 pixels (vertical 2 × horizontal 2), for example, 2 pixels only in the vertical or horizontal direction, or 4 pixels (vertical 2 × horizontal 2) or more, Further, a plurality of pixel addition modes having different numbers of added pixels may be provided (however, the CCD 3 needs to have a structure capable of supporting a plurality of types of pixel addition modes).

  In particular, when the number of effective pixels of the CCD 3 is higher than that of the present embodiment, such as 10 million pixels, a pixel addition mode in which the number of added pixels is 4 pixels (2 × 2 horizontal) or more, For example, a 25-pixel addition mode in which the number of added pixels is 25 pixels (vertical 5 × horizontal 5) may be provided. In that case, for a specific image signal readout method in the 25-pixel addition mode, the signal charges of 25 pixels of the same color that are adjacent in the horizontal direction and the vertical direction are added, and this is added to the signal charge for one pixel of that color. Any method can be adopted as long as it can be read as:

  As a method for reading an image signal in the 25-pixel addition mode, for example, signal charges of pixels arranged in every 5 pixels in the horizontal and vertical directions in the effective pixel area of the CCD 3 are used. There is a method of reading out signal charges obtained by adding signal charges for pixels. FIG. 8 is a conceptual diagram corresponding to FIG. 4 showing the outline, and each color (R, R in the figure) forming the Bayer arrangement within the effective pixel region of the CCD 3 (in the drawing, the portion including the upper left of the effective pixel region). Gr, Gb, B) pixels and the positional relationship between the pixels from which the charge signal (added charge signal) is read out in the 25-pixel addition mode, that is, the pixels constituting the Bayer data (the pixels indicated by thick frames in the figure) FIG. In the figure, the pixel indicated by “Gr” is the G color pixel in the row where the R color pixel is arranged, and similarly the pixel indicated by “Gb” is the G color in the row where the R color pixel is arranged. Pixels.

  The above readout method will be described more specifically. With regard to Gr pixels, pixel areas such as (1, 1) to (9, 9) are targeted for addition, and all Gr pixels arranged in that area are added. The signal charge is added, and the signal charge after the addition is read as the signal charge of the Gr pixel such as the center (5, 5) of the region. Similarly, for the R pixel, the pixel regions (6, 1) to (14, 9), etc. are added, the signal charges of all the R pixels arranged in that region are added, and the signal after the addition The charge is read out as the signal charge of the R pixel such as the center (10, 5) of the region. For the B pixel, the pixel areas (1, 6) to (9, 14), etc. are added, the signal charges of all the B pixels arranged in that area are added, and the signal after addition is added. The charge is read out as a signal charge of the B pixel such as the center (10, 5) of the region. For Gb pixels, the pixel areas (6, 6) to (14, 14), etc. are added, and the signal charges of all the Gb pixels arranged in that area are added, and the signal after addition is added. The charge is read out as a signal charge of the Gb pixel such as the center (10, 10) of the region.

  That is, by shifting the pixel area to be added for each color of R, Gr, Gb, and B for each color so that the distance between the centers of the areas is 5 pixels, the horizontal and vertical directions in the effective pixel area are obtained. It consists of signal charges of pixels arranged at equal intervals in the direction, and the number of pixels in the vertical and horizontal directions is 1/5 each, but only a small number of pixels (2 in the case shown in FIG. This is a method of reading out an imaging signal reflecting pixel information of almost all pixels except pixels in the rows and fourth rows and pixels in the second and fourth columns).

  The image signal readout method in the 25-pixel addition mode is not limited to the above-described method. For example, by matching pixel regions to be added for each color of R, Gr, Gb, and B as much as possible, As in the case of 4-pixel addition shown in FIG. 4, a method of reading an imaging signal composed of signal charges (signal charges after addition) of R, Gr, Gb, and B pixels in contact with each other may be used.

  As the CCD 3, for example, the effective pixel number is about 10 million pixels, and the maximum recording image size that can be recorded at the time of still image shooting is 3: 4, “2,700 × 3,600”, In the case of providing two types of pixel addition modes, the above-described 4-pixel addition mode and 25-pixel addition mode, the following can be performed.

  That is, the setting information 200 as shown in FIG. 9 is stored in the program memory 19 or the like in place of the setting information 100 shown in FIG. The illustrated example is an example in which the user can set four levels of “high, medium 1, medium 2, and low” as the resolution level for a still image. In the recording mode, for example, the CPU 13 performs processing having substantially the same contents as those shown in FIGS. 5 and 6, and at this time, in step S4 (FIG. 5), the 25-pixel addition mode is set as the driving mode of the CCD 3. . Further, immediately after step S14 (FIG. 5), the driving mode of the CCD 3 is set to a mode corresponding to the recorded image size according to the setting information 200, and then the moving image shooting process (FIG. 6) after step S15 is performed. Also in step S24, the driving mode of the CCD 3 is set to a mode corresponding to the recorded image size according to the setting information 200.

  Also in such a modification, during still image shooting or moving image shooting, the drive mode of the CCD 3 is set to the pixel addition mode (4 pixel addition mode or 25 pixel addition mode), and the captured image is vertically or vertically or horizontally and horizontally. The necessary recording image size can be ensured by changing the cut width of the surplus portion to be cut. Therefore, similar to the embodiment described above, not only can the image of the required aspect ratio be acquired, but even when the required image size is small, the pixel information obtained at the time of imaging is effectively used. A high quality image can be obtained. Also, a high quality image can be obtained for the through image.

  In addition, since the driving mode of the CCD 3 at the time of moving image shooting is the 25 pixel addition mode, the effective number of pixels of the CCD 3 is about 10 million pixels, and the maximum recording image size that can be recorded by still image shooting is “2,700 × 3”. , 600 ”, the number of pixels before the surplus portion is cut from the top, bottom, top, bottom, left, and right of the captured image is equal to or greater than the maximum number of pixels that can be processed by the MPEG compression / decompression block 9. By using the number of added pixels, a series of data processing such as generation, compression, and recording of frame data during moving image shooting can be performed very efficiently.

  In the above description, the case where the present invention is applied to a digital camera having a still image shooting function and a moving image shooting function has been described. However, the present invention is not limited thereto, and the present invention is not limited to this. The present invention can also be applied to other imaging devices such as an attached PDA. Further, the present invention can also be applied to those having only a still image shooting function or only a moving image shooting function (whether or not a through image display function is provided).

1 is a block diagram of a digital camera according to the present invention. It is a conceptual diagram which shows the setting information used at the time of operation | movement in a recording mode. It is a schematic diagram of CCD which shows the principle of the reading method of the image signal by pixel addition mode. It is the conceptual diagram which showed the Bayer data which consists of an imaging signal read by pixel addition mode. It is a flowchart which shows the processing content of CPU in a recording mode. It is a flowchart following FIG. It is the figure which showed the relationship between the effective pixel area | region (a) of CCD, the imaging data (b) read by pixel addition mode, and the number of pixels of the vertical / horizontal direction in frame data (c). It is the conceptual diagram which showed an example of the Bayer data which consist of an imaging signal read by 25 pixel addition mode. It is a conceptual diagram of the setting information corresponding to FIG. 2 which shows a modification.

Explanation of symbols

1 Camera body 3 CCD
6 DSP section 7 Timing generator 8 JPEG compression / decompression block 9 MPEG compression / decompression block 11 Display controller 12 LCD
13 CPU
14 Internal Memory 19 Program Memory 20 Recording Media 100 Setting Information 200 Setting Information

Claims (13)

In an imaging apparatus including an imaging element that captures a subject image,
Reading means for reading out the image data of the subject image from the image sensor by adding pixels;
Image generating means for generating an image with a predetermined aspect ratio by deleting an excess portion having a predetermined width along a predetermined side of the image from an image based on the image data read by the reading means; An imaging apparatus characterized by that.   The image generation unit generates an image having a predetermined aspect ratio by deleting, from the image based on the image data read by the reading unit, an excess portion having a predetermined width at the top and bottom and / or left and right of the image. The imaging apparatus according to claim 1.   The imaging apparatus according to claim 1, wherein the image generation unit generates an image having a predetermined aspect ratio different from an aspect ratio of an effective pixel region in the imaging element.   4. The image pickup apparatus according to claim 1, wherein the image generation unit generates an image having a plurality of types of aspect ratios different from an aspect ratio of an effective pixel region in the image pickup device.   The image generation means generates an image having the same aspect ratio as that of the effective pixel area in the image sensor, in addition to an image having a predetermined aspect ratio different from the aspect ratio of the effective pixel area in the image sensor. Item 5. The imaging apparatus according to Item 3 or 4.   6. The image generating unit generates a plurality of types of images having different aspect ratios from images based on image data having the same number of added pixels read by the reading unit. The imaging device described.   Readout control means for controlling the pixel addition number at the time of reading image data from the image sensor by the reading means to a pixel addition number corresponding to the size of the image generated by the image generation means is provided. The imaging device according to claim 1. The reading means includes, as a reading mode for reading image data of the subject image from the image sensor, a pixel addition mode for reading the image data by adding pixels, and a normal mode for reading the image data without performing pixel addition. Have
The readout control unit controls the readout mode in the readout unit to the pixel addition mode or the normal mode according to the size of the image generated by the image generation unit, and the number of pixel additions in the image data read out by the readout unit The image pickup apparatus according to claim 7, wherein a pixel addition number corresponding to a size of an image generated by the image generation unit is controlled. Compression means for compressing image data generated by the image generation means;
Recording means for recording the compressed image data compressed by the compression means,
The imaging apparatus according to claim 1, wherein the compression unit has a data processing capability according to the number of pixels of the image generated by the image generation unit.   The image generation means generates an image having a predetermined aspect ratio constituting a moving image from an image based on image data read out from the image sensor at a predetermined period by the reading means. 9. The imaging device according to any one of 9. The recording unit records a still image generated by the image generation unit during still image shooting and a moving image generated by the image generation unit during moving image shooting,
The read control unit includes a pixel addition number in the image data read by the reading unit during the still image shooting, and a pixel addition number including a number smaller than the pixel addition number in the image data read by the reading unit during the moving image shooting. The imaging apparatus according to claim 10, wherein the imaging apparatus is controlled as follows. In an imaging method of an imaging device provided with an imaging device that images a subject image,
A step of adding pixel data to read out the image data of the subject image from the image sensor; and
Generating an image having a predetermined aspect ratio by deleting a surplus portion having a predetermined width along a predetermined side of the image from an image based on the read image data. In a computer included in an image pickup apparatus having an image pickup device for picking up a subject image,
A process for adding and reading out image data of the subject image from the image sensor;
A program for executing processing for generating an image having a predetermined aspect ratio by deleting an excess portion having a predetermined width along a predetermined side of the image from an image based on the read image data.

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