JP5957813B2 - Imaging apparatus, program, and recording medium - Google Patents

Description

  The present invention relates to an imaging device, a program, and a recording medium.

  The color reproduction range (color gamut) that can be displayed on display devices such as liquid crystal displays and flat-screen TVs has been on the rise in recent years, and specific colors defined by sRGB, Rec709, and adobeRGB, which are conventional standard standards It has become possible to display a wider color gamut, not just the spatial color gamut.

  The digital camera has a wider color gamut than the specific color space. Therefore, many digital cameras use a first format such as a JPEG format that records image data in a color gamut of a predetermined color space, and a RAW that records image data in a color gamut wider than the first format. The photographer can selectively select two types of file formats such as data and the second format before photographing (Patent Documents 1 and 2).

  By the way, in the wide color gamut display device described above, when displaying an image having a color gamut of a wide color space, an image exceeding the color gamut of the conventional color space is converted into an image of a color gamut expanded straightly and displayed. Therefore, the image area is often displayed with a distinctly different vivid color. Therefore, in order to correspond to the color gamut of the wide color gamut display device, it is desired to save all of the imaging data in a second format file format such as RAW data.

JP 11-261933 A Japanese Patent Application Laid-Open No. 2001-223979

  However, if all the imaging data is saved in a file format of the second format such as RAW, many images that are not necessary to be saved as RAW data are included, and handling and management of the subsequent data becomes very complicated. Problems arise. There is also a problem that the data capacity increases.

  The present invention has been made in view of this point, and provides an imaging apparatus, a program, and a recording medium that can store an image in a file format of an optimal format based on the color gamut of the captured image. Objective.

According to one aspect of the imaging apparatus illustrating the present invention, the color gamut of image data in a color space having a color gamut wider than the color gamut of the sRGB color space is all or only part of the color gamut of the sRGB color space. JPEG image data is generated by encoding the image data according to the sRGB color space when the determination unit determines that the image data is all within the color gamut of the sRGB color space. When the determination unit determines that only a part of the color gamut of the sRGB color space exists, the image data is subjected to a process different from the encoding according to the sRGB color space to perform a first process. And an image processing unit that performs processing for generating image data and processing for converting the image data into second image data in the sRGB color space .

In addition, when the determination unit determines that all exist in the color gamut of the sRGB color space, the generated JPEG image data is stored in a storage medium, and the determination unit is partially in the color gamut of the sRGB color space. A storage unit that stores the generated first image data and the second image data in a storage medium when it is determined that only the image data exists.

Further, the first image data may be RAW data.

  Further, the present invention may be an invention of a computer-readable program and a recording medium recording the computer-readable program.

  Since the present invention includes color gamut determination means for determining whether the color gamut of the specific color space converted by the color gamut conversion means is wider than the color gamut of the predetermined color space, the wide color gamut area is included in the captured image. Whether it exists or not can be determined for each shooting. As a result, the image data can be stored in the file format of the optimum format based on the color gamut of the captured image data.

It is a block diagram which shows the principal part of the digital camera which is one Embodiment of the imaging device of this invention. It is a rear view of a digital camera. It is a flowchart which shows the operation | movement procedure of a digital camera. It is a reference diagram showing an example of an image captured at the time of shooting. FIG. 4 is an xy chromaticity diagram illustrating, in a plane, an sRGB color gamut and a color gamut of image data converted into an XYZ color space. It is explanatory drawing which blinked and displayed black in the wide color gamut area | region among the images for a display displayed on LCD. It is a rear view of the camera body which shows other embodiment which provided LED which lights when a wide color gamut area | region exists.

  As shown in FIG. 1, a digital camera 10 to which the present invention is applied includes an imaging unit 11, a development processing unit 12, a color space conversion unit 13, an image processing unit 14, a compression / decompression processing unit 15, an SDRAM 16, a media controller 17, and a display. A control unit 18, a CPU 19, a card memory 20, and an LCD 21 are provided. Reference numeral 22 denotes a bus.

  The imaging unit 11 includes a photographic lens 23, a single-plate color imaging sensor 24, an AFE 25, and the like. The imaging unit 11 performs various processes on the imaging signal obtained from the color imaging sensor 24 and generates RAW (Bayer) data. And stored in the SDRAM 16.

  The development processing unit 12 performs development processing (Bayer → RGB conversion) of the RAW data stored in the SDRAM 16 and outputs the RGB data subjected to the development processing to the color space conversion unit 13.

  The color space conversion unit 13 converts the RGB data obtained by the development processing unit 12 into the sYCC color space at the time of recording and stores it in the SDRAM 16, and reads out the data of the sYCC color space from the SDRAM 16 at the time of reproduction. Convert to spatial data (sRGB data). Note that instead of the sRGB color space, it may be converted into a well-known adobeRGB color space or the like.

  The display control unit 18 reduces the sRGB data so as to match the resolution of the LCD 21, creates a display image, and displays the created display image on the LCD 21 as a storage image for a predetermined time.

  The image processing unit 14 performs processing such as size conversion and image adjustment on the sYCC data obtained by the color space conversion unit 13 and stores it in the SDRAM 16.

  The compression / decompression processing unit 15 reads sYCC data that has undergone image processing at the time of recording from the SDRAM 16, compresses the read sYCC data into a JPEG format that performs color gamut compression in the sRGB color space, and at the time of playback, the JPEG format The compressed image data is read from the card memory 20 and the sRGB data obtained by decompressing it is stored in the SDRAM 16.

  The media controller 17 controls reading and writing of RAW data and JPEG data to the card memory 20.

  The CPU 19 is connected to an operation unit 30 including a release button, a shooting mode selection operation unit, a power switch, and the like, and controls each unit in response to an instruction from the operation unit 30. The shooting mode selection operation unit selects either the normal shooting mode or the wide color gamut shooting mode. In the normal shooting mode, the captured image data is stored in the card memory 20 as a JPEG compressed file obtained by color gamut compression into sRGB.

  In the wide color gamut shooting mode, it is determined whether or not there is a wide color gamut area in the shooting target area of the stored image. If there is, the RAW data (second format image data) is stored in the card memory 20. If it does not exist, it is saved as a JPEG format (first format) file that has been gamut-compressed to sRGB.

  A nonvolatile memory 31 and a buffer memory 32 are connected to the CPU 19. The nonvolatile memory 31 stores a control program that is referred to when the CPU 19 performs various controls. The CPU 19 controls each part (circuit) using the buffer memory 32 as a temporary storage work area in accordance with a control program stored in the nonvolatile memory 31, and activates the function of each part (circuit) of the digital camera 10. .

  The CPU 19 determines whether or not there is a wide color gamut area in the imaging target area of the imaging data, and the color gamut conversion unit 26, the color gamut inside / outside determination unit 27, the wide color gamut display control unit 28, A color gamut recording control unit 29 is provided. These are generated by executing a control program stored in the nonvolatile memory 31.

  The color gamut conversion unit 26 calculates the color gamut of the shooting target area of the image data obtained at the time of shooting. This is because the RGB data subjected to the development processing by the development processing unit 12 is converted into an XYZ color space defined by the CIE (International Illumination Commission) by a 3 × 3 matrix circuit obtained from the spectral characteristics of the color image sensor 24 (specific illumination). It can be calculated by converting to a color gamut. The XYZ color space is a CIE-XYZ color space and is a device-independent color space. The color gamut of a specific device-independent color space may be converted to a color gamut of the CIE-L * a * b * space in addition to the color gamut of the XYZ color space.

  The color gamut inside / outside determination unit 27 compares the color gamut of the specific color space with the color gamut of the predetermined color space, and determines whether or not the color gamut of the shooting target region is wider than the color gamut of the predetermined color space. Determine. The comparison is performed for all pixels in the imaging target area. In the determination, if even one pixel does not fall within the color gamut of the predetermined color space, it is determined that a wide color gamut region exists.

  Note that the color gamut inside / outside determination unit 27 may perform smoothing processing on XYZ data and determine only pixels that are skipped in the horizontal or vertical direction in the smoothed XYZ data. In this case, since it is not necessary to compare all the pixels, the processing speed is improved. The color gamut of a predetermined color space may be a color gamut of a standard color space such as sRGB or adobeRGB, or a color gamut of a color space defined by the user.

  The wide color gamut display control unit 28, when the color gamut inside / outside determination unit 27 determines that the wide color gamut region exists in the photographing target region, the wide color gamut region in the display image displayed on the LCD 21 is black for a certain period of time. Controls blinking display.

  The wide color gamut recording control unit 29 controls to record RAW data in the card memory 20 when the color gamut inside / outside determination unit 27 determines that a wide color gamut region exists in the shooting target region. If it is determined that the wide color gamut area does not exist, image processing is performed on the RGB data in the sYCC color space, and then the JPEG format file is stored in the card memory 20 by sRGB color gamut compression. It controls the image processing unit 14, the compression / decompression processing unit 15, the media controller 17, and the like.

  As shown in FIG. 2, the operation unit is provided with a mode selection operation unit adjacent to the LCD 21. The mode selection operation unit includes a mode menu button 33 and a cross key 34. The LCD 21 displays a menu screen, a shooting mode selection screen, and the like in addition to displaying a stored image and a reproduced image. Reference numeral 35 denotes a release button, 36 denotes a power switch, and 37 denotes a viewfinder eyepiece window.

  Next, the operation of the above configuration will be described with reference to FIG. After the power switch 36 of the digital camera 10 is turned on (S-1), the wide-gamut shooting mode is selected by operating the shooting mode selection operation units 33 and 34 (S-2). Then, after looking through the finder eyepiece window 37 and performing framing, the shutter release is performed by operating the release button 35 (S-3).

  In response to the shutter release, the CPU 19 captures RAW data from the imaging unit 11 and stores it in the SDRAM 16 (S-4). Thereafter, the CPU 19 sends the RAW data read from the SDRAM 16 to the development processing unit 12. The development processing unit 12 converts the RAW data into RGB data, and stores the converted RGB data in the SDRAM 16 (S-5).

  Thereafter, the CPU 19 sends the saved RGB data to the color space conversion unit 13 to convert it into the sYCC color space, and then converts it into the sRGB color space (S-6), and the converted sRGB color space data (sRGB data). The data is sent to the display control unit 18. The display control unit 18 reduces the sRGB data so as to match the resolution of the LCD 21 (S-7), and displays the reduced display image on the LCD 21 as a storage image for a certain time (S-8). ).

  On the other hand, the CPU 19 reads the developed RGB data from the SDRAM 16 and determines whether a wide color gamut area exists in the shooting target area of the RGB data (S-9). For determination, the color gamut conversion unit 26 of the CPU 19 converts the RGB image data into image data in the XYZ color space by a 3 × 3 matrix circuit obtained from the spectral characteristics of the color image sensor 24. Thereafter, the color gamut inside / outside determination unit 27 of the CPU 19 compares the color gamut of the image data in the XYZ color space with the color gamut of the predetermined color space, and the color space of the image data in the XYZ color space is determined in advance. It is determined whether it is wider than the color gamut.

  For example, it is assumed that the RGB data is an image obtained by copying azaleas as shown in FIG. The RGB data is converted into the XYZ color space, and the color gamut of the converted XYZ color space is compared with the color gamut of a predetermined color space, for example, the color gamut of the sRGB color space, as shown in FIG. FIG. 5 illustrates the three primary colors of sRGB on the xy chromaticity diagram representing the color in a plane. The triangle 40 converts the color gamut of the sRGB color space, and the black-filled portion 41 converts to the XYZ color space. The color gamut of the obtained image data is shown respectively. In the color gamut of the XYZ color space, a region 41a that cannot be expressed in the sRGB color space exists from blue to green. Thereby, it can be seen that the image data converted into the color gamut of the XYZ color space has a wide color gamut region wider than the color gamut of the predetermined color space.

  When the CPU 19 determines that a wide color gamut area exists in the image data converted into the color gamut of the XYZ color space by the color gamut inside / outside determination unit 27, the CPU 19 operates the wide color gamut display control unit 28. As shown in FIG. 6, the wide color gamut display control unit 28 blinks and displays the wide color gamut region in black 42 in the shooting target region of the display image displayed on the LCD 21 (S-10). As a result, the photographer can recognize that there is a wide color gamut region by visually recognizing the LCD 21, and can also recognize at a glance which region in the image the region is.

  Thereafter, the CPU 19 operates the wide color gamut recording control unit 29. The wide color gamut recording control unit 29 reads RAW data from the SDRAM 16 and includes the read RAW data and various parameters such as color reproduction characteristic information and shooting information of the imaging unit 11 that has captured the RAW data, for example, TIFF / EP. RAW image data in a file format conforming to the standard (second format file) is generated, and the generated RAW image data is stored in the card memory 20 by controlling the media controller 17 (S-11). The color reproduction characteristic information is supplementary information for obtaining a development color conversion matrix to be applied in the development process, and is generated in advance when the digital camera 10 is manufactured and stored in the nonvolatile memory 31.

  When the wide color gamut area does not exist, the CPU 19 controls the image processing unit 14 and the compression / decompression processing unit 15 to perform image processing on the data converted into the sYCC color space (S-12). The image-processed sYCC color space data is encoded according to the sRGB color space to create JPEG image data (first format file) (S-13), and the created JPEG image data is used as a file as a card. Save in the memory 20 (S-14). At this time, since the data to be stored is image data having no wide color gamut region, excessive color gamut compression is not performed, and therefore, a more natural image can be stored.

  In the above embodiment, when there is a wide color gamut area, the black color 42 indicating that the wide color gamut area exists is displayed blinking on the display image, but it may not be blinked. Alternatively, as shown in FIG. 7, an LED 45 for wide color gamut determination is provided on the back of the camera body, and the LED 45 is turned on for a certain time in response to determining that the wide color gamut region exists. May be. A lamp may be used instead of the LED 45. Further, a speaker may be provided on the camera body to notify for a certain period of time with sound.

  In each of the above embodiments, when there is a wide color gamut region, the raw data before demosaicing is saved, but in addition to this raw data, image data that has been color gamut compressed in the sRGB or adobeRGB color space is added together. May be saved. At this time, they may be stored in association with each other.

  In each of the above-described embodiments, when there is no wide color gamut area, it is saved as a JPEG format compressed file, but other compressed format files may be used. Further, it may be saved in a file format that is not compressed.

  In each of the above embodiments, when a wide color gamut area exists, the raw data before demosaicing is saved as a file as it is, but the developed RGB data may be saved as raw data. In this case, it is desirable to store an ICC (International Color Consortium) profile unique to the camera in a non-volatile memory in advance, read the ICC profile, and save the image data with the embedded profile.

  In each of the above embodiments, the digital camera is described. However, the present invention is not limited to the digital camera, and can be used for an imaging apparatus such as a video camera, a mobile phone with a camera, and a smartphone.

  Further, the present invention is not limited to the imaging apparatus, and may be applied to a computer with a camera, for example. In this case, the present invention is achieved by supplying a computer with a storage medium storing software program codes for implementing the present invention, and reading and executing the program codes stored in the storage medium. In this case, the program code itself read from the storage medium realizes the present invention, and the storage medium storing the program code constitutes the present invention.

  Moreover, it does not need to have a camera. In this case, instead of the image acquisition unit, the input unit for inputting RAW image data from the outside, and the type of the image pickup apparatus, for example, a digital camera, is read from the shooting information included in the RAW image data and the spectral sensitivity characteristics of the image pickup sensor are obtained. A specifying unit for specifying. Note that the information on the spectral sensitivity characteristics of the image sensor for each camera type is recorded in advance in the software, and the information is stored in a storage unit such as a hard disk by installing it. The spectral sensitivity characteristic of the image sensor may be specified by referring to the information.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. -RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM, etc. can be used. Furthermore, the program code may be downloaded via a network.

11 Imaging unit 21 LCD
26 Color gamut conversion unit 27 Color gamut inside / outside determination unit 28 Wide color gamut display control unit 29 Wide color gamut recording control unit 45 LED

Claims (7)

a determination unit that determines whether the color gamut of the image data in a color space having a color gamut wider than the color gamut of the sRGB color space is all or only part of the color gamut of the sRGB color space;
When the determination unit determines that the image data is all within the color gamut of the sRGB color space, the image data is encoded in accordance with the sRGB color space to generate JPEG image data. when it is determined that only a portion is present in the color gamut of the color space, the encoding tailored to the sRGB color space to the image data and generating a first image data by performing different processing, the image data An image processing unit that performs a process of converting the image data into second image data in the sRGB color space . The imaging device according to claim 1,
When the determination unit determines that all are in the color gamut of the sRGB color space, the generated JPEG image data is stored in a storage medium, and the determination unit is only partially in the color gamut of the sRGB color space. An imaging apparatus including a storage unit that stores the generated first image data and the second image data in a storage medium when it is determined that they exist. In the imaging device according to claim 1 or 2,
The imaging apparatus, wherein the first image data is RAW data. a determination step of determining whether the color gamut of the image data in a color space having a color gamut wider than the color gamut of the sRGB color space is all or only part of the color gamut of the sRGB color space;
In the determination step, when it is determined that the image data is all within the color gamut of the sRGB color space, the image data is encoded according to the sRGB color space to generate JPEG image data. In the determination step, the sRGB color space is generated. when it is determined that only a portion is present in the color gamut of the color space, the encoding tailored to the sRGB color space to the image data and generating a first image data by performing different processing, the image data A program for causing a computer to execute an image processing step of performing a process of converting the image data into the second image data in the sRGB color space . The program according to claim 4, wherein
When it is determined in the determination step that the image data is all within the color gamut of the sRGB color space, the generated JPEG image data is stored in a storage medium, and in the determination step, only a part of the color gamut of the sRGB color space is stored. A program for further executing a storing step of storing the generated first image data and the second image data in a storage medium when it is determined that they exist. In the program according to claim 4 or 5,
The program in which the first image data is RAW data.   A computer-readable recording medium on which a program for executing the program according to claim 4 is recorded.