JP2010136387A - Still image generator, still-image generating program and method for generating still image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate a still image composed of proper image quality from a frame image constituting an animation. <P>SOLUTION: A first contrast curve A1 for a still image is read from a ROM, while a second contrast curve A2 for an animation is read. The reversed curve of the read second contrast curve A2 is calculated, and the calculated reversed curve is used as a third contrast curve. The third contrast curve A3 is multiplied by the first contrast curve A1, and the obtained value is used as a fourth contrast curve. Accordingly, the fourth contrast curve A4 is obtained. The fourth contrast curve A4 is applied to the frame signal of the previously read and expanded animation, and the still image is generated by carrying out a contrast-conversion processing (step S7). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a still image generation device, a still image generation program, and a still image generation method that generate a still image from an arbitrary frame image constituting a moving image.

  2. Description of the Related Art Conventionally, a still image generating apparatus that generates a still image from a moving image that has been captured in advance and stored in a memory has been proposed. When the user designates a frame to be printed in the moving image data stored in the memory, the still image generating apparatus stores the position information of the designated frame to be printed. Then, the moving image data is read from the memory based on the stored frame position information, and still image data is generated from the moving image data of the frame specified by the frame position information in the moving image data. By sending the generated still image data to a printer via an interface, any frame image in the moving image data can be printed and output as a still image (see, for example, Patent Document 1). ).

JP 2004-179823 A

  However, when a moving image is shot and the moving image data is stored in the memory, various image processing is performed so that when the moving image is projected as a moving image on a home TV screen, the image quality is optimized on the home TV screen. Is done. In other words, although the image quality of a TV for home use cannot be generally defined by the model and its adjustment value, the factory default value is adjusted so that high saturation / high-saturation, that is, flashy image creation, is generally achieved with high key / high contrast. It has been shipped. Therefore, when played on such a home TV screen, various image quality parameters of the moving image are adjusted and stored in the memory so that the optimum image quality is obtained. For example, the contrast, saturation, sharpness of the moving image, etc. The image quality parameter has a lower value than that of a still image. In other words, it is assumed that it will be produced and reproduced on the home TV screen in advance.

  Therefore, when a frame of a moving image whose image quality has been adjusted in advance is printed and output as a still image as it is like the conventional still image generation device described above, or displayed on a personal computer screen, the image is "dark" This results in the impression that “there is a lack of vividness”, and still images with appropriate image quality cannot be obtained.

  The present invention has been made in view of such a conventional problem, and is a still image generation device, a still image generation program, and a still image generation capable of generating a still image having an appropriate image quality from frame images constituting a moving image. It aims to provide a method.

  In order to solve the above-mentioned problem, the still image generating apparatus according to the first aspect of the present invention is an acquisition unit that acquires a frame image from a moving image that is composed of a plurality of frame images and that has been subjected to image processing for moving images; And still image generation means for generating a still image subjected to image processing for still images by performing predetermined image processing on the frame image subjected to the image processing for moving image acquired by the means. Therefore, no matter what image quality parameters are applied to a moving image for which a still image is to be obtained from an arbitrary frame image, predetermined image processing is performed on the frame image acquired by the acquiring means. It is possible to generate a still image having an appropriate image quality that has been subjected to image processing for a still image.

  According to a second aspect of the present invention, there is provided a still image generating device that captures a moving image and performs image processing for the moving image, and a still image that captures the still image and performs image processing for the still image. Image capturing means; and a recording means for recording a moving image and a still image captured by each of the capturing means and subjected to each of the image processing, wherein the acquiring means is configured to record the frame from the moving image recorded in the recording means. The image is acquired, and the recording unit further records the still image generated by the still image generating unit. Therefore, in a digital camera or the like having a moving image capturing unit that captures a moving image and performs image processing for the moving image and a still image capturing unit that captures a still image and performs image processing for the still image, the image is captured by the moving image capturing unit. It is possible to generate a still image having image quality characteristics equivalent to that of the still image captured by the still image capturing means of the digital camera from the frame image constituting the moving image.

  In the still image generating device according to a third aspect of the present invention, each of the image processing is gamma processing, and the still image generating means applies the frame image of the moving image to which the moving image gamma processing is applied. By performing predetermined gamma processing, a still image subjected to gamma processing for a still image is generated. Therefore, no matter what gamma processing for moving images is applied to a moving image for which a still image is to be obtained from an arbitrary frame image, the predetermined gamma processing is applied to the frame image acquired by the acquisition means, It is possible to generate a still image having an appropriate image quality that has been subjected to the gamma processing.

  According to a fourth aspect of the present invention, there is provided a still image generating device for converting the frame image of the moving image subjected to the moving image gamma processing into a still image subjected to the still image gamma processing. Storage means for storing a gamma curve, wherein the still image generation means performs gamma processing based on the gamma curve stored in the storage means on the frame image of the moving image that has been subjected to gamma processing for the moving image. Thus, a still image subjected to gamma processing for a still image is generated. Therefore, based on the stored gamma curve, a still image having an appropriate gamma characteristic can be surely generated by simple processing.

  Further, in the still image generation device according to the fifth aspect, the still image generation means performs first image processing information for performing image processing for the still image and image processing for moving image. And a second image processing information for storing a still image subjected to image processing for a still image by performing image processing based on each image processing information stored in the storage device. Generate. Therefore, based on the stored first and second image processing information, it is possible to generate a still image having an appropriate image quality with a simple process.

  Further, in the still image generating device according to the invention of claim 6, the still image generating means includes the third image processing information having reverse characteristics based on the second image processing information. And calculating means for calculating the fourth image processing information based on the calculated third image processing information and the first image processing information. The image processing based on the second image processing information includes: The frame image of the applied moving image is subjected to image processing based on the fourth image processing information to generate a still image that has been subjected to image processing for a still image.

  That is, when the third image processing information having a reverse characteristic to the second contrast information applied to the moving image is applied to the frame image in the moving image (first application), the frame image once has the equilibrium characteristic. . Therefore, if the first image processing information is applied to the frame image having the balanced characteristics (second application), the frame image is changed to the optimum image quality for still images. Therefore, the fourth image processing information is calculated in advance by superimposing the first image processing information and the third image processing information having a reverse characteristic with respect to the second image processing information. If the information is applied, the first and second applications are performed at the same time, and the frame image changes to an optimum image quality for still images.

  Further, in the still image generation device according to claim 7, each of the image processes is a saturation adjustment process, and the still image generation unit is configured to process the moving image subjected to the saturation adjustment process for the moving image. A still image that has been subjected to saturation adjustment processing for a still image is generated by performing predetermined saturation adjustment processing on the frame image. Therefore, regardless of the moving picture saturation adjustment processing that is performed on a moving image for which a still image is to be obtained from an arbitrary frame image, the predetermined saturation adjustment processing is performed on the frame image acquired by the acquisition means. Thus, it is possible to generate a still image having an appropriate image quality that has been subjected to saturation adjustment processing for the still image.

  Further, in the still image generation device according to an eighth aspect of the invention, each of the image processes is a filter process, and the still image generation unit applies the frame image of the moving image to which the moving image filter process has been performed. A still image subjected to still image filter processing is generated by performing predetermined filter processing. Therefore, no matter what kind of moving image filter processing is applied to a moving image for which a still image is to be obtained from an arbitrary frame image, a predetermined filtering process is performed on the frame image acquired by the acquisition unit, thereby It is possible to generate a still image having an appropriate image quality that has been subjected to the filtering process.

  Further, in the still image generation device according to the ninth aspect of the present invention, each of the image processes is an exposure adjustment process, and the still image generation unit includes the frame of the moving image that has been subjected to the exposure adjustment process for the moving image. By performing a predetermined exposure adjustment process on the image, a still image subjected to the exposure adjustment process for the still image is generated. Therefore, even if exposure adjustment processing for any moving image is performed on a moving image to obtain a still image from an arbitrary frame image, by performing predetermined exposure adjustment processing on the frame image acquired by the acquisition unit, It is possible to generate a still image having an appropriate image quality that has been subjected to exposure adjustment processing for the still image.

  Further, in the still image generation device according to the invention of claim 10, the acquisition unit selects a frame image from the moving image and acquires the frame, and the frame acquired by the first acquisition unit A second acquisition unit that acquires a plurality of frame images that are temporally close to the image, wherein the still image generation unit includes a still image corresponding to the frame image acquired by the first acquisition unit, A single still image including the still image corresponding to the frame image acquired by the second acquisition unit is generated. Therefore, if a desired frame image is selected from a moving image, a plurality of frame images that are temporally close to the frame image are automatically selected, and a still image including a plurality of still images having optimum image quality is generated. The

  According to an eleventh aspect of the present invention, there is provided a still image generation program for acquiring a frame image from a moving image that is composed of a plurality of frame images and subjected to image processing for moving images. And still image generating means for generating a still image subjected to image processing for still images by performing predetermined image processing on the frame image subjected to the image processing for moving image acquired by the acquiring means. Make it work. Therefore, when the computer executes processing according to this program, the same effects as those of the first aspect of the invention can be obtained.

  A still image generation method according to the invention of claim 12 is obtained by an acquisition step of acquiring a frame image from a moving image that is composed of a plurality of frame images and subjected to image processing for moving images, and acquired by this acquisition step. A still image generating step of generating a still image subjected to still image processing by performing predetermined image processing on the frame image subjected to the moving image processing. Therefore, by performing the processing according to the described steps, the same effects as those of the first aspect of the invention can be achieved.

  As described above, according to the present invention, a frame image acquired by the acquisition unit is predetermined even if image processing for a moving image is performed with any image quality parameter on a moving image for which a still image is to be obtained from an arbitrary frame image. By performing this image processing, it is possible to generate a still image having an appropriate image quality subjected to still image processing.

1 is a block diagram of a digital camera according to an embodiment of the present invention. It is a figure which shows the contrast characteristic used in the same embodiment. It is a figure which shows the saturation characteristic used in the same embodiment. (A) is a figure which shows the sharpness filter characteristic for still images, (b) is a figure which shows the sharpness filter characteristic for moving images. It is a flowchart which shows the process sequence in the embodiment. It is a figure which shows the exposure characteristic used in the modification of embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a circuit configuration of a digital camera 1 according to an embodiment of the present invention. This digital camera 1 has a still image shooting function and a moving image shooting function, and has a CCD 2 and a DSP / CPU 3, and the CCD 2 is provided with a primary color filter of a Bayer arrangement in a photosensitive portion. It is. The DSP / CPU 3 is a one-chip microcomputer that has various digital signal processing functions including image data compression / decompression and audio data processing and controls each part of the digital camera 1.

  A TG (Timing Generator) 4 that drives the CCD 2 is connected to the DSP / CPU 3, and a unit circuit 5 that receives an analog imaging signal corresponding to the optical image of the subject output from the CCD 2 is connected to the TG 4. Has been. The unit circuit 5 includes a correlated double sampling circuit (CDS circuit) that reduces drive noise of the CCD 2 included in the imaging signal output from the CCD 2, and an automatic gain control circuit (AGC circuit) that adjusts the gain of the signal after noise reduction. ), Including an A / D converter that converts the gain-adjusted signal into a digital signal, converts an analog imaging signal input from the CCD 2 into a digital image signal, that is, Bayer data, and sends it to the DSP / CPU 3.

  A display device 6 and a key input unit 7 are connected to the DSP / CPU 3, and a buffer memory (DRAM) 11, a ROM 12, a storage memory 13, and an input / output interface 14 are connected via an address / data bus 10. Yes. The buffer memory 11 is a buffer for temporarily storing the Bayer data and the like, and is also used as a working memory for the DSP / CPU 3.

  That is, the DSP / CPU 3 performs processing such as pedestal clamping on the Bayer data sent from the unit circuit 5 and then converts the data into RGB data, and further converts the RGB data into a luminance (Y) signal and a color difference (UV). Convert to signal. The YUV data converted by the DSP / CPU 3 stores data for one frame in the buffer memory 11. One frame of YUV data stored in the buffer memory 11 is sent to the display device 6, where it is converted into a video signal and then displayed as a through image.

  Further, when a shutter key operation by the user is detected in the still image shooting mode, the still image shooting process is performed by switching the CCD 2 and the unit circuit 5 to a still image shooting driving method and drive timing different from those for through image shooting. The YUV data for one frame stored in the buffer memory 11 by this still image shooting processing is encoded after being compressed by the DSP / CPU 3 using the JPEG method or the like and converted into a file in the buffer memory 11. The still image data is recorded in the storage memory 13 via the address / data bus 10.

  In addition, when a recording start instruction is detected by a user operating a shutter key in the moving image shooting mode, the moving image shooting is performed by switching the CCD 2 and the unit circuit 5 to a driving method and driving timing for moving image shooting different from those at the time of through image shooting. The processing starts, and the YUV data stored in the buffer memory 11 by the moving image photographing process is sequentially sent to the DSP / CPU 3 and is encoded after data compression by a predetermined MPEG codec. The buffer memory 11 and the address / data bus 10 are sequentially written in the storage memory 13 as frame data (video data). Such a series of operations is repeatedly executed for each frame, and YUV data (compressed data) in the buffer memory 11 is rewritten sequentially. That is, stream recording is performed. Further, the DSP / CPU 3 expands the still image or moving image data read from the storage memory 13 when reproducing the still image or moving image, and the image data work area of the buffer memory 11 as still image data or moving image frame data. Expand to.

  The display device 6 includes a color LCD and its driving circuit, and displays the subject image captured by the CCD 2 as a through image when in the shooting standby state, and is read out from the storage memory 13 and expanded when the recorded image is played back. The recorded image is displayed. The key input unit 7 includes a plurality of operation keys such as a shutter key and a power key, and outputs a key input signal corresponding to the key operation by the user to the DSP / CPU 3. The shutter key also functions as a recording start / end button when shooting a moving image.

  The ROM 12 is a program diagram showing combinations of aperture values (F) and shutter speeds corresponding to appropriate exposure values (EV) at the time of shooting such as still image shooting, moving image shooting, and through image shooting. Are also stored. The charge accumulation time set by the DSP / CPU 3 based on the shutter speed set by the program diagram is supplied as a shutter pulse to the CCD 2 via the TG 4, and the charge accumulation time, that is, the exposure time is obtained by operating the CCD 2 in accordance with this. Is controlled. That is, the CCD 2 functions as an electronic shutter.

  Further, the ROM 12 stores a program shown in a flowchart to be described later and various programs necessary for functioning as a digital camera, and a first contrast curve (gamma curve) A1 for a still image shown in FIG. A second contrast curve (gamma curve) A2 for moving images, a first saturation curve B1 for still images shown in FIG. 3, a second saturation curve B2 for movies, and the stillness shown in FIG. A sharpness filter C1 for images and a sharpness filter C2 for moving images are stored.

  Note that the digital camera 1 includes the input / output interface 14, and thus can be connected to an external device such as a printer, a personal computer, or a TV receiver via the input / output interface 14.

  In the present embodiment having the above configuration, when the user operates the shutter key in the state where the still image shooting mode is set, the CCD 2 and the unit circuit 5 are set to the drive method and drive timing for still image shooting. The still image shooting process is executed by switching, and the YUV data for one frame stored in the buffer memory 11 by the still image shooting process is converted by the DSP / CPU 3 into the first contrast curve A1 and the first saturation curve. B1, image processing is performed by applying a stillness sharpness filter C1. Thereafter, the data is compressed after being compressed by the JPEG method, coded into a file in the buffer memory 11, and then recorded as still image data (still image file) in the storage memory 13 via the address / data bus 10.

  In addition, when a recording start operation is performed by a shutter key operation by a user in a state where the moving image shooting mode is set, moving image shooting processing is performed by switching the CCD 2 and the unit circuit 5 to a driving method and driving timing for moving image shooting. The YUV data stored in the buffer memory 11 by the moving image shooting process is sequentially sent to the DSP / CPU 3, and the second contrast curve A2, the second saturation curve B2, and the sharpness filter C2 for moving images are applied. Image processing. Thereafter, the data is compressed after being compressed by the MPEG codec, and finally encoded, and recorded as a moving image file in the storage memory 13 via the address / data bus 10.

  When the moving image file is stored in the storage memory 13 as described above, when the still image creation mode is set by a predetermined operation of the key input unit 7 by the user, the DSP / CPU 3 is based on the program. The processing shown in the flowchart of FIG. 5 is executed. That is, the user selects and plays back any moving image file stored in the storage memory 13 by operating the key input unit 7, selects an arbitrary frame image, and instructs to generate a still image from the moving image frame. (Step S1). Then, the DSP / CPU 3 reads out the moving image frame signal of the frame instructed to be selected from the moving image file, decompresses it in the buffer memory 11, and converts it into YUV data (step S2).

  Subsequently, the first contrast curve A1 for the still image is read from the ROM 12 (step S3), and the second contrast curve A2 for the moving image is read (step S4). Then, the inverse curve of the second contrast curve A2 read in step S4 is calculated, and this is used as the third contrast curve (step S5). Therefore, as a result of the process in step S5, as shown in FIG. 2, a third contrast curve A3, which is an inverse curve of the second contrast curve A2, is obtained.

  Further, the third contrast curve A3 is multiplied by the first contrast curve A1 to obtain a fourth contrast curve (step S6). As a result of the processing in step S6, a fourth contrast curve A4 is obtained as shown in FIG. The moving image frame signal read out and expanded in step S2, that is, YUV data for one frame, is subjected to a contrast conversion process by applying the fourth contrast curve A4 (step S7).

  In other words, as described above, when the third contrast curve A3 having a reverse characteristic with respect to the applied second contrast curve A2 is applied to the expanded moving image frame signal (frame image) at the time of moving image shooting (first image). Application), as shown in FIG. 2, the gamma characteristic (gamma curve) of the moving picture frame signal once becomes a balanced gamma E1. Therefore, if the first contrast curve A1 is applied to the moving image frame signal having the balanced gamma E1 (second application), the gamma characteristic (gamma curve) of the moving image frame signal is the optimum contrast for still images. That is, it changes to a certain first contrast curve A1. Therefore, the fourth contrast curve A4 is calculated in advance by superimposing the third contrast curve A3 having the opposite characteristic to the second contrast curve A2 and the first contrast curve A1 (step S6). If the fourth contrast curve A4 is applied (step S7), the first and second applications are performed simultaneously, and the gamma characteristic (gamma curve) of the frame image is the optimum contrast for still images. 1 to a contrast curve A1.

Moreover, when each contrast curve is shown by a transfer function,
First contrast curve A1 = H (S)
Second contrast curve A2 = G (S)
Assuming that
F (S) = (1 / G (S)) × H (S)
A gamma such as F (S) can be applied to a moving image signal all at once. This curve is the fourth contrast curve A4.

  In the present embodiment, the fourth contrast curve A4 is calculated by performing the processing of step S3 to step S6. However, the fourth contrast curve A4 is stored in the ROM 12 and is simply stored. The fourth contrast curve A4 may be read from the ROM 12 in one step and applied to the moving image frame signal in step S7. In this way, it is only necessary to read out the fourth contrast curve A4 from the ROM 12 without performing the processing of steps S3 to S6, and the processing can be simplified. Further, the third contrast curve A3 may be stored in the ROM 12. In this case, it is not necessary to perform the processing of step S4 and step S5, so that the processing can be simplified also in this case.

  Subsequently, the first saturation curve B1 for still image is read from the ROM 12 (step S8), and the second saturation curve B2 for moving image is read (step S9). Then, an inverse curve of the second saturation curve B2 read out in step S9 is calculated and used as a third saturation curve (step S10). Further, the third saturation curve is multiplied by the first saturation curve B1 to obtain a fourth saturation curve (step S11). As a result of the processing in step S11, a fourth saturation curve B4 is obtained as shown in FIG. Then, a process of applying saturation conversion to the one frame of YUV data to which the fourth contrast curve A4 is applied in step S7 by applying the fourth saturation curve B4 is performed (step S12).

  That is, as described above, when a third saturation curve having a reverse characteristic to the applied second saturation curve B2 is applied to the expanded moving image frame signal (frame image) at the time of moving image shooting (first image). As shown in FIG. 3, the saturation characteristic (saturation curve) of the moving image frame signal once becomes the equilibrium saturation E2. Therefore, if the first saturation curve B1 is applied to the moving image frame signal having the equilibrium saturation E2 (second application), the saturation characteristic (saturation curve) of the moving image frame signal is for a still image. That is, the first saturation curve B1 which is the optimum saturation is changed. Therefore, the fourth saturation curve B4 is calculated in advance by superimposing the third saturation curve B3 having the opposite characteristic to the second saturation curve B2 and the first saturation curve B1 (step S4). S11) If this fourth saturation curve B4 is applied (step S12), the first and second applications are performed simultaneously, and the frame image has the first saturation that is the optimum saturation for still images. Changes to the saturation curve B1.

  In the present embodiment, the fourth saturation curve B4 is calculated by performing the processing from step S8 to step S11. However, the fourth saturation curve B4 is stored in the ROM 12 in advance. Alternatively, the fourth saturation curve B4 may be read from the ROM 12 in a single step, and applied to the moving image frame signal in step S12. In this way, it is only necessary to read out the fourth saturation curve B4 from the ROM 12 without performing the processing of steps S8 to S11, and the processing can be simplified. Further, the third saturation curve may be stored in the ROM 12. In this way, it is not necessary to perform the processing of step S9 and step S10, so that in this case as well, the processing can be simplified.

  Subsequently, the first sharpness filter curve C1 for still images is read from the ROM 12 (step S13), and the second sharpness filter curve C2 for moving images is read (step S14). Then, the inverse curve of the second sharpness filter curve C2 read out in step S14 is calculated, and this is used as the third sharpness filter curve (step S15). Further, the third sharpness filter curve is multiplied by the first sharpness filter curve C1 to obtain a fourth sharpness filter curve (step S16). Then, the fourth sharpness filter curve is applied to one frame of YUV data to which the fourth contrast curve A4 is applied in step S7 and the fourth saturation curve B4 is applied in step S12. Then, sharpness filter processing is performed (step S17).

  That is, as described above, when a third sharpness filter curve having a reverse characteristic with respect to the applied second sharpness filter curve C2 is applied to the expanded moving image frame signal (frame image) at the time of moving image shooting (first image). And the sharpness filter characteristic (sharpness filter curve) of the moving image frame signal is once balanced. Therefore, if the first sharpness filter curve C1 is applied to the balanced moving image frame signal (second application), the sharpness filter characteristic (sharpness filter curve) of the moving image frame signal is the optimum sharpness for still images. That is, the first sharpness filter curve C1 is changed. Therefore, the fourth sharpness filter curve is calculated in advance by superimposing the third sharpness filter curve having the reverse characteristic to the second sharpness filter curve C2 and the first sharpness filter curve C1 (step S16). If this fourth sharpness filter curve is applied (step S17), the first and second applications are performed simultaneously, and the sharpness filter characteristic (sharpness filter curve) of the frame image is optimal for still images. It changes to the first sharpness filter curve C1 which is the sharpness.

  That is, the transfer function of the filter applied to the still image is H (S), and the transfer function of the filter applied to the moving image is G (S). At this time, if a transfer function F (S) such that F (S) = (1 / G (S)) × H (S) is applied to the frame of the moving image, the optimum sharpness of the still image is obtained. is there.

  In the present embodiment, the fourth sharpness filter curve is calculated by performing the processing of step S13 to step S16. However, the fourth sharpness filter curve is stored in the ROM 12 and is simply stored. The fourth sharpness filter curve may be read from the ROM 12 in one step and applied to the moving image frame signal in step S17. In this way, it is only necessary to read out the fourth sharpness filter curve from the ROM 12 without performing the processing of steps S13 to S16, and the processing can be simplified. Further, the third sharpness filter curve may be stored in the ROM 12. In this way, it is not necessary to perform the processing of step S14 and step S15, so that in this case as well, the processing can be simplified.

  Subsequently, processing necessary for conversion into a still image signal and layout processing on the layout are performed (step S18). Here, in the present embodiment, a total of nine still images including the immediately preceding 4 frames and the immediately following 4 frames together with the moving image frame selected by the user in step S1 are laid out into one still image file. It is something to save. Therefore, in this step S18, the still image converted into the optimum contrast or the like by the processing in steps S2 to S17 described above is laid out in a predetermined area.

  Next, it is determined whether or not the processing for the last frame in the nine frames has been completed (step S19). If the process for the last frame among these nine frames is not completed, the determination in step S19 is NO. Therefore, in this case, after the next processing target frame is selected (step S20), the processing from step S2 is repeated.

  When the processing for the last frame in nine frames is completed, the determination in step S19 is YES, and the combined still image data obtained by combining and laying out nine still image data (YUV data) is JPEG converted. Then, it is stored in the storage memory 13 (step S21). Therefore, when the still image file stored in the storage memory 13 is supplied to the printer or the personal computer via the input / output interface 14, the impression that the image is “dark”, “hazy”, or “not enough vividness”. Still images can be printed or displayed.

  (Modification of this embodiment)

  FIG. 6 shows a modification of the present embodiment, and the ROM 12 has a first contrast for the still image similar to the first contrast curve A1 for the still image shown in FIG. In addition to the curve (gamma curve) F1 and the second contrast curve A2 for moving picture shown in FIG. 2, a second contrast curve (gamma curve) F2 used in the still image creation mode is stored. The second contrast curve F2 is obtained by adding appropriate exposure for moving images to the second contrast curve A2 for moving images shown in FIG. In other words, as described above, the image quality of a home TV is adjusted and shipped so that high-key / high-contrast and high-saturation, that is, flashy picture creation is made. Therefore, the contrast curve for moving images has a lower value than that of a still image so as to obtain an optimum image quality when reproduced on such a home TV screen. Further, not only the contrast curve, but also the exposure determination value determined as “appropriate exposure” may be different from that of the still image. In other words, when shooting a moving image, the exposure may be underexposed than when shooting a still image and take a lower value than that of a still image. Therefore, the second contrast curve F2 for creating a still image in this modified example is a characteristic in which the gain of the exposure correction amount for moving images (underexposure) is added to the second contrast curve A2 (FIG. 2). It is said that.

  Therefore, in the state in which the moving image shooting mode is set, when a recording start operation is performed by a user's shutter key operation, the moving image shooting process is performed by switching the CCD 2 and the unit circuit 5 to a moving image shooting driving method and drive timing. The YUV data stored in the buffer memory 11 by the moving image shooting process is sequentially sent to the DSP / CPU 3 and is subjected to image processing by applying the second contrast curve A2. Thereafter, the data is compressed after being compressed by the MPEG codec, and finally encoded, and recorded as a moving image file in the storage memory 13 via the address / data bus 10.

  In addition, when generating a still image from an arbitrary frame image in the moving image file stored in the storage memory 13, the same processing as that in steps S3 to S7 in the flowchart of FIG. 5 described above may be performed. That is, the first contrast curve F1 for the still image is read from the ROM 12 (step S3), and the second contrast curve F2 for creating the still image is read (step S4). Then, an inverse curve of the second contrast curve F2 read out in step S4 is calculated and used as a third contrast curve (step S5). Therefore, by the process in step S5, as shown in FIG. 6, a third contrast curve F3, which is an inverse curve of the second contrast curve F2, is obtained.

  Further, the third contrast curve F3 is multiplied by the first contrast curve F1 to obtain a fourth contrast curve (step S6). As a result of the processing in step S6, a fourth contrast curve F4 is obtained as shown in FIG. Then, the moving image frame signal read and expanded in step S2, that is, YUV data for one frame, is subjected to a contrast conversion process by applying the fourth contrast curve F4 (step S7).

  In this modification as well, the fourth contrast curve F4 is stored in the ROM 12, the fourth contrast curve F4 is read from the ROM 12 in a single step, and this is applied to the moving image frame signal in step S7. You may do it. Further, the third contrast curve F3 may be stored in the ROM 12.

  Also, in this modification, the case where still image generation processing is performed using a contrast curve that takes exposure correction for moving images into account has been shown. However, only exposure correction is separately added without adding exposure correction to the contrast curve. Alternatively, a conversion process may be executed to generate a still image.

  In the embodiment and the modification, the image quality parameter of the still image generated from the frame image is completely matched with the image quality parameter of the captured still image by using a characteristic opposite to the image quality characteristic for moving images. However, a parameter different from the reverse characteristic may be applied for the purpose of “slightly seasoning the moving image because of insufficient sharpness”.

  In the embodiment, a still image file is created by automatically combining a plurality of still images corresponding to a plurality of frame images. However, only a single still image is generated. May be.

  Furthermore, in the embodiment, the moving image is processed with a fixed characteristic curve. However, in a camera that shoots a moving image while changing the gamma curve instead of being fixed, how is it associated with each frame? It is also conceivable to record related information indicating whether a gamma curve is applied and determine an inverse gamma curve to be applied with reference to the related information when generating a still image. Also, since recording related information for each frame increases the processing load required for recording, a gamma curve or the like most frequently applied to the moving image may be recorded for each moving image file.

  In addition, in the above-described embodiment, the processing shown in the flowchart of FIG. 5 is executed in the state of YUV data, or contrast conversion processing is performed in the state (stage) of YUV data during still image shooting and moving image shooting. The saturation conversion process, the sharpness filter process, the exposure conversion process, and the like are executed, but the same process may be executed according to the state (stage) of the Bayer data or the RGB data.

1 Digital camera 2 CCD
3 DSP / CPU
4 TG
5 Unit Circuit 6 Display Device 7 Key Input Unit 10 Data Bus 11 Buffer Memory 12 ROM
13 Storage memory 14 Input / output interface

Claims (12)

An acquisition unit configured to acquire a frame image from a moving image that includes a plurality of frame images and that has been subjected to image processing for the moving image;
Still image generation means for generating a still image subjected to image processing for still images by performing predetermined image processing on the frame image subjected to the image processing for moving image acquired by the acquisition means. Still image generating apparatus characterized by that. Movie shooting means for shooting a movie and performing image processing for the movie,
Still image photographing means for photographing a still image and performing image processing for the still image;
A recording unit that records a moving image and a still image that have been imaged by each of the imaging units and subjected to the image processing;
The acquisition unit acquires the frame image from the moving image recorded in the recording unit,
The still image generating apparatus according to claim 1, wherein the recording unit further records the still image generated by the still image generating unit. Each image processing is gamma processing,
The still image generating means generates a still image subjected to gamma processing for still images by performing predetermined gamma processing on the frame image of the moving images subjected to gamma processing for the moving images. The still image generating device according to claim 1 or 2. Storage means for storing a gamma curve for converting the frame image of the moving image subjected to the gamma processing for the moving image into a still image subjected to the gamma processing for the still image;
The still image generating unit performs gamma processing for still images by performing gamma processing based on the gamma curve stored in the storage unit on the frame image of the moving image that has been subjected to gamma processing for moving images. 4. The still image generating apparatus according to claim 1, wherein the still image is generated. The still image generation means includes storage means for storing first image processing information for performing image processing for the still image and second image processing information for performing image processing for the moving image. ,
The still image according to claim 1, 2 or 3, wherein a still image subjected to image processing for a still image is generated by performing image processing based on each image processing information stored in the storage means. Image generation device. The still image generation means calculates third image processing information having reverse characteristics based on the second image processing information, and based on the calculated third image processing information and the first image processing information. A calculation means for calculating the fourth image processing information;
Still images obtained by performing image processing for still images by performing image processing based on the fourth image processing information on the frame images of the moving image subjected to image processing based on the second image processing information The still image generation device according to claim 5, wherein: Each of the image processes is a saturation adjustment process,
The still image generation means performs a predetermined saturation adjustment process on the frame image of the moving image that has been subjected to the saturation adjustment process for the moving image, thereby performing a still image subjected to the saturation adjustment process for the still image The still image generating device according to claim 1, wherein the still image generating device generates a still image. Each of the image processes is a filter process,
The still image generation means generates a still image subjected to still image filter processing by performing predetermined filter processing on the frame image of the moving image subjected to the moving image filter processing. The still image generating device according to claim 1. Each of the image processes is an exposure adjustment process,
The still image generation means generates a still image subjected to exposure adjustment processing for a still image by performing predetermined exposure adjustment processing on the frame image of the moving image subjected to exposure adjustment processing for the moving image. The still image generating apparatus according to claim 1, wherein The acquisition means includes first acquisition means for selecting and acquiring a frame image from the moving image;
A second acquisition means for acquiring a plurality of frame images that are temporally close to the frame image acquired by the first acquisition means;
The still image generation unit includes a single still image including a still image corresponding to the frame image acquired by the first acquisition unit and a still image corresponding to the frame image acquired by the second acquisition unit. 10. The still image generating apparatus according to claim 1, wherein the image is generated. A computer included in the still image generation device,
An acquisition unit configured to acquire a frame image from a moving image that includes a plurality of frame images and that has been subjected to image processing for the moving image;
By performing predetermined image processing on the frame image subjected to the image processing for moving image acquired by the acquiring unit, the functioning as a still image generating unit that generates a still image subjected to image processing for still image is performed. Still image generation program characterized by that. An acquisition step of acquiring a frame image from a moving image that is composed of a plurality of frame images and subjected to image processing for the moving image;
A still image generation step of generating a still image subjected to the image processing for the still image by performing predetermined image processing on the frame image subjected to the image processing for the moving image acquired by the acquisition step. Still image generation method characterized by the above.

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