JP2004240992A - Output image adjustment of image file - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image output device capable of correctly outputting color space information in image data creation. <P>SOLUTION: A CPU 31 of a color printer 20 executes gamma correction and matrix calculation M to image data of an RGB color space obtained by calculation of a matrix S. The CPU 31 executes a gamma conversion process to image data by using a set gamma correction value. The matrix calculation M is a calculation process for converting the RGB color space into an XYZ-based color space. When the matrix calculation M is executed, the CPU 31 refers to a Print Matching tag in order to reflect a color space in creating the image data, and the matrix calculation is executed by using a matrix (M) corresponding to the written color space. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a processing technique involving conversion of image data on a color space.

  In recent years, there has been an increasing demand for digital still cameras (DSC), digital video cameras (DVC), scanners, and the like that can use captured images or captured images as easily handled image files. Generally, in a DSC or the like, photographed image data is stored as a JPEG format file which is one of image compression file formats. In this JPEG file, image data is represented using a YCbCr color space in order to increase the compression ratio. Therefore, DSCs or the like convert captured image data expressed in the RGB color space into the YCbCr color space. At this time, the RGB color space handled by the DSC or the like uses the color space of a CRT monitor (for example, sRGB: IEC61966 2-1) which is used as a standard in personal computers.

  In a personal computer, the RGB color space is used as a standard color space for image data. Therefore, a personal computer that receives such a JPEG file decompresses the JPEG file and converts the color space of the image data into a YCbCr color space. To the RGB color space. The image data converted into the RGB color space is displayed on a monitor or converted into the CMYK color space, and then printed out on a print medium via a printer.

JP-A-11-331622

  In image processing in a conventional personal computer, generally, output from a CRT monitor is assumed, and the color space of image data converted from the YCbCr color space to the RGB color space is a color space characteristic that can be expressed by the CRT monitor. At the same time, clipping was performed in the sRGB color space commonly used in personal computers.

  Therefore, when the JPEG file generated by the image data generating device such as DSC is decompressed by a personal computer and converted from the YCbCr color space to the RGB color space, the color gamut of the RGB color space of the image data is changed to the sRGB color space. Even when the color gamut is wider than the color gamut, the color values outside the color gamut of the sRGB color space have been rounded. In such a case, color values outside the color gamut of the sRGB color space are not reflected in the output image. As a result, even if the color reproduction range of the output device is wider than the sRGB color space, the color reproduction capability of the output device cannot be utilized, and the color reproduction capability available on the DSC can be effectively used. There was a problem that you can not.

  On the other hand, the sRGB color space that matches the color reproduction characteristics of the monitor is widely used as a standard RGB color space, and the display by the monitor is also used in the color space conversion process from the YCbCr color space to the RGB color space. Currently, a color conversion matrix based on the assumption is used. Therefore, even if a new RGB color space having a color gamut wider than the color gamut of the sRGB color space is newly defined, a new RGB color space is used as a color space for executing image processing from the input device to the output device. Unless is adopted, there is a problem that the color space characteristics cannot be easily changed because of lack of versatility.

  To solve these problems, some image file users use image file correction software or the like to adjust the image of the image file so as to obtain an appropriate output result reflecting the color space of the DSC or the like. However, such image adjustment is complicated.

  SUMMARY An advantage of some aspects of the invention is to provide an image output apparatus that can accurately output color space information at the time of generating image data. It is another object of the present invention to provide an image output device that can effectively use the color gamut of a device that generates image data or a device that outputs image data.

  In order to solve the above-described problem, a first aspect of the present invention relates to a method of combining image data with usage information associated with the image data, which indicates whether to use information outside a region of a predetermined color space. Provided is an image processing apparatus that performs image processing using the same. An image processing apparatus according to a first aspect of the present invention includes: an image data capturing unit configured to capture the image data; a usage information obtaining unit configured to obtain the usage information associated with the image data; Determining means for determining whether to use the information outside the area of the predetermined color space based on the information, and, when it is determined that the information outside the area is used, the information outside the area is defined as the definition area. And image processing means for executing image processing of the image data including color conversion processing to a wide color space having a wide defined area that can be included in the image data.

  According to the image processing apparatus of the first aspect of the present invention, when information outside a region of a predetermined color space is used, a wide-area color having a wide definition region capable of including the outside-of-region information in the definition region Since the image processing of the image data including the color conversion processing to the space is executed, the image data can be accurately reproduced by using the colorimetric values included in the image data when the image data is generated.

  In the image processing apparatus according to the first aspect of the present invention, when it is determined that the out-of-area information is not used, the image processing unit may determine a predetermined color having a defined area equivalent to the predetermined color space. Image processing of the image data may be performed via a space. With this configuration, even when it is determined that the out-of-area information is not used, image processing can be performed using the predetermined information.

  In the image processing device according to the first aspect of the present invention, the image data is defined by a first color space, and the image data capturing unit converts the color space of the captured image data into the first color space. Converting the color space of the image data defined by the second color space into a third color space using the out-of-region color values. You may.

  With such a configuration, when the color space of the image data represented by the second color space is converted to the third color space, the color space can be converted using the out-of-region color values. The image data can be accurately reproduced by using the colorimetric values included in the image data when the image data was generated.

  In the image processing device according to the first aspect of the present invention, the first color space is a YCbCr color space, the second color space is a first RGB color space, and the third color space is a third color space. The space may be a second RGB color space having a defined area wider than the first RGB color space. Further, the second RGB color space may be an sRGB color space. Further, the third color space may be a CIELAB color space instead of the second RGB color space.

  When such a configuration is provided, an image can be output using image data having the second RGB color space wider than the first RGB color space, so that image data having the first RGB color space is used. It is possible to output an image having a higher saturation than the above. Further, when the color space of the output data is the CIELAB color space, color matching is facilitated, which is convenient when performing image processing in another device.

In the image processing device according to the first aspect of the present invention,
The image data includes a first positive colorimetric value that is a colorimetric value within the defined area of the predetermined color space and a second positive colorimetric value that is a colorimetric value outside the defined area of the predetermined color space. Including at least one of a color specification value and a negative color specification value, and being represented by the first color space;
The image data capturing unit changes the color space of the image data from the first color space to a second color space using the first and second positive color values and the negative color values. It may be converted. With this configuration, it is possible to execute image processing that reflects the first and second positive colorimetric values and the negative colorimetric values of the image data. Can be improved.

  In the image processing device according to the first aspect of the present invention, the image processing unit uses a first gamma correction value when the image data has the first and second positive colorimetric values, When the image data has a negative color specification value, the image processing apparatus may further include a gamma correction unit that performs gamma correction on the image data by using a second gamma correction value different from the first gamma correction value. good. With this configuration, appropriate gamma correction can be performed in each of the case where the image data has a positive color value and the case where the image data has a negative color value.

  In the image processing device according to the first aspect of the present invention, the second gamma correction value may be a value smaller than the first gamma correction value. In such a case, the negative color value can be used more effectively, and the color reproduction area of the image data can be further expanded.

  In the image processing device according to the first aspect of the present invention, the image processing means is expressed by the second color space and the first positive color value, the second positive color value Value and the image data including the negative colorimetric value are wider than the second color space, and at least one of the second positive colorimetric value and the negative colorimetric value is included in the definition area. It may be converted to a third color space including the third color space. In such a case, at least one of the second positive color value and the negative color value that could not be expressed in the second color space is included in the definition area of the third color space. At least one of the second positive color value and the negative color value can be reproduced and output. Therefore, the saturation of the image data can be improved, and the color gamut of the device that generates the image data or the device that outputs the image data can be effectively used.

  In the image processing device according to the first aspect of the present invention, the first color space is an RGB color space represented by an R component, a G component, and a B component, and the second gamma correction value is May be different, the second gamma correction value for the R component, the second gamma correction value for the G component, and the second gamma correction value for the B component. With this configuration, it is possible to execute gamma correction according to the expression area of each of the R component, the G component, and the B component on image data having a negative colorimetric value, and to increase the saturation. High image output can be obtained.

  In the image processing apparatus according to the first aspect of the present invention, the conversion of the color space of the image data from the first color space to the second color space by the image file importing unit is performed by using the first color The first matrix operation is performed on the image data represented by the space, and the conversion of the color space of the image data from the second color space to the third color space by the image processing means is performed by the image processing unit. It may be executed by a second matrix operation process on the image data expressed in the second color space.

  According to a second aspect of the present invention, a first positive colorimetric value which is represented by a first color space and is a colorimetric value within a color gamut of a predetermined color space; And an image processing apparatus that performs image processing using image data including at least one of a second positive color value and a negative color value that are color values outside the color gamut. An image processing apparatus according to a second aspect of the present invention comprises: an image data acquisition unit configured to acquire the image data; and the first and second positive colorimetric values and the negative colorimetric value. A color space of the image data from the first color space, which is wider than the predetermined color space, and includes at least one of the second color value and the negative color value in its color gamut; Color space conversion means for converting into a color space.

  According to the image processing apparatus according to the second aspect of the present invention, the image data color space is converted to the second colorimetric value and the second colorimetric value using the first and second positive colorimetric values and the negative colorimetric values. Since at least one of the negative colorimetric values is converted to the second color space including the colorimetric gamut, the image data is accurately reproduced by using the colorimetric values included in the image data when the image data was generated. be able to.

  The image processing apparatus according to the second aspect of the present invention can be realized in various other modes in the same manner as the image processing apparatus according to the first aspect.

  The image processing apparatus according to the first or second aspect of the present invention may further include a printing unit that prints the image data on which the image processing has been executed on a print medium. In such a case, image data subjected to image processing can be output. Further, the image data and the usage information may be stored in the same image file. In such a case, the image data and the usage information can be handled in image file units, so that the association between the image data and the usage information can be facilitated.

  According to a third aspect of the present invention, image data is output using image data and use information indicating whether or not to use an out-of-region color value that is a color value outside a defined region of a predetermined color space. Provide a program to be output by the device. A program according to a third aspect of the present invention determines whether or not to use the out-of-area color value based on the function of capturing the image data and the use information associated with the captured image data. Function, and when it is determined that the out-of-area color values are used, the image processing of the image data is performed through a color space having a wide defined area that can include the out-of-area color values in the defined area. A computer executes the function to be executed and the function to output the image data subjected to the image processing.

  According to the program of the third aspect of the present invention, the same operation and effect as those of the image processing apparatus according to the first aspect of the present invention can be obtained. Further, the program according to the third aspect of the present invention can be realized in various aspects in the same manner as the image processing device according to the first aspect of the present invention.

  According to a fourth aspect of the present invention, there is provided an apparatus for generating image data for outputting image data in association with image processing control information for specifying image processing conditions for the image data. An image data generating apparatus according to a fourth aspect of the present invention includes: an image data obtaining unit configured to obtain the image data; Image processing control information generating means for generating the image processing control information including use information indicating whether or not to use the image data; and outputting the obtained image data and the generated image processing control information in association with each other. Image data output means.

  According to the image data generation device according to the fourth aspect of the present invention, the image processing control information including usage information indicating whether to use information outside the area of the predetermined color space, the acquired image data and Can be output in association with each other, so that image processing can be performed on image data using information outside the area.

  According to a fifth aspect of the present invention, there is provided an image data generation apparatus for outputting image data in association with image processing control information for specifying image processing conditions for the image data. The image data generating apparatus according to a fifth aspect of the present invention includes a first positive colorimetric value that is a colorimetric value within a color gamut of a predetermined color space, and a table outside the color gamut of the predetermined color space. An image data generating unit that generates the image data including at least one of a second positive color value and a negative color value that are color values, and performing image processing on the image data. Usage information indicating whether or not to use at least one of the second positive colorimetric value and the negative colorimetric value, and the image data being the first and second positive colorimetric values Image processing including a first gamma correction value to be used when image data has a negative color specification value and a second gamma correction value different from the first gamma correction value to be used when the image data has a negative color specification value Image processing control information generating means for generating control information To.

  According to the image data generation device of the fifth aspect of the present invention, at least one of the second positive color value and the negative color value that are color values outside the color gamut of the predetermined color space. Can be output in association with image processing control information including use information indicating whether or not to use the acquired image data, so that at least the second positive colorimetric value and the negative colorimetric value Image processing can be performed on image data using either one of them.

  In the image data generating device according to a fifth aspect of the present invention, the image processing control information includes a second table that is wider than the predetermined color space when performing color space conversion of the image data. A color space conversion characteristic for converting at least one of the color value and the negative color value into a color space including the color gamut may be included. In such a case, it is possible to specify the color space conversion characteristics at the time of color conversion of the image data, and it is possible to improve the effect of using the second positive color value and the negative color value.

  According to a sixth aspect of the present invention, image data is output using image data represented by a first color space and use information indicating whether information outside a region of a predetermined color space is to be used. Provide a way to A method according to a sixth aspect of the present invention includes obtaining the image data, converting a color space of the obtained image data from the first color space to a second color space, and based on the usage information. It is determined whether or not to use the out-of-region information. If it is determined that the out-of-region information is to be used, the color of the image data represented by the second color space is determined using the out-of-region information. Converting the color space into a third color space and outputting the converted image data.

  According to the method according to the sixth aspect of the present invention, it is possible to obtain the same operational effects as those of the image processing apparatus according to the first aspect of the present invention. Further, the method according to the sixth aspect of the present invention can be realized in various aspects in the same manner as the image processing apparatus according to the first aspect of the present invention.

  A seventh aspect of the present invention provides a method for outputting image data. A method according to a seventh aspect of the present invention includes obtaining the image data represented by a first color space, and converting the color space of the obtained image data from the first color space to a second color space. And holds the information on the second color space obtained by the conversion and the information outside the area that defines the second color space, and reflects the held information to obtain the second color space. The color space of the image data represented by the color space is converted to a third color space, and the converted image data is output.

  According to the method according to the seventh aspect of the present invention, it is possible to obtain the same operational effects as those of the image processing apparatus according to the first aspect of the present invention. Further, the method according to the seventh aspect of the present invention can be realized in various aspects in the same manner as the image processing apparatus according to the first aspect of the present invention.

  An eighth aspect of the present invention provides an image processing method for image data. An image processing method according to an eighth aspect of the present invention obtains the image data based on a first color space, and changes the color space of the obtained image data from the first color space to a second color space. After the conversion, the information in the area and the area outside the area that define the second color space for the converted image data is held, and the information is expressed by the second color space by reflecting the held information. The present invention is characterized in that a color space of existing image data is converted into a third color space having a defined area wider than the second color space.

  According to the method according to the eighth aspect of the present invention, it is possible to obtain the same operational effects as those of the image processing apparatus according to the second aspect of the present invention. Further, the method according to the eighth aspect of the present invention can be realized in various aspects in the same manner as the image processing apparatus according to the second aspect of the present invention.

  A ninth aspect of the present invention provides an image processing apparatus that performs image processing on image data. The image processing means according to a ninth aspect of the present invention comprises: an image data capturing means for capturing the image data; and an instruction as to whether information outside a predetermined color space area included in the image data is to be used. Instruction means for performing, and when the use of the out-of-area information is instructed, the image data of the image data including a color conversion process to a wide-area color space having a wide defined area capable of including the out-of-area information in the defined area. Image processing means for executing image processing.

  In the image processing apparatus according to the ninth aspect of the present invention, when the use of the out-of-area information is not instructed, the image processing unit may use a predetermined color having a defined area equivalent to the predetermined color space. Image processing of the image data may be performed via a space.

  In addition, the image processing apparatus according to the present invention includes an image data capturing unit that captures the image data, and information outside of a predetermined color space area included in the image data. The image processing apparatus may be an image processing apparatus that performs image processing on image data including image processing means that performs image processing on. In such a case, since the image processing is performed using information outside the area of the predetermined color space, the saturation of an image obtained as a result of the image processing can be improved.

  The image processing in the image processing means may further include a color conversion process to a wide-area color space having a wide defined area capable of including the out-of-area information in the defined area. In such a case, since a wide area color space that can include information outside the area in the predetermined color space in the defined area is used, information outside the area in the predetermined color space is reproduced, and The saturation of an image obtained as a processing result can be improved. Further, the information outside the area of the predetermined color space may be a negative image data value, and the gamma correction value for the negative image data value may be different from the gamma correction value for the positive image data value. good. In such a case, gamma correction suitable for the tone characteristics of the positive image data value and the tone characteristics of the negative image data value can be executed.

Hereinafter, an image output apparatus according to the present invention will be described based on some embodiments with reference to the drawings in the following order.
A. B. Configuration of image data output system including image output device Configuration of image output device Image processing in image output device Other embodiments

A. Configuration of image data output system to which image output device can be applied:
A configuration of an image data output system to which the image processing device according to the first embodiment can be applied will be described with reference to FIGS. FIG. 1 is an explanatory diagram showing an example of an image data output system to which the image output device according to the first embodiment can be applied. FIG. 2 is a block diagram showing a schematic configuration of a digital still camera capable of generating an image file (image data) output by the image output device according to the first embodiment.

  The image data output system 10 includes a digital still camera 12 as an input device for generating an image file, and a color camera as an output device for executing image processing based on the image file generated by the digital still camera 12 and outputting an image. A printer 20 is provided. As the output device, in addition to the printer 20, a monitor 14 such as a CRT display and an LCD display, a projector, and the like can be used. In the following description, the color printer 20 is used as the output device.

  The digital still camera 12 is a camera that obtains an image by forming light information on a digital device (CCD or photomultiplier), and as shown in FIG. 2, an optical circuit 121 for collecting light information. An image acquisition circuit 122 for controlling a digital device to acquire an image, an image processing circuit 123 for processing an acquired digital image, and a control circuit 124 for controlling each circuit are provided. The digital still camera 12 stores the obtained image as digital data in a memory card MC as a storage device. As a storage format of image data in the digital still camera 12, a JPEG format is generally used, but other storage formats such as a TIFF format, a GIF format, a BMP format, and a RAW format may be used. The digital still camera 12 also has a selection / decision button 126 for selecting and setting various functions.

  Image data generated by the digital still camera 12 is defined in an RGB color space. As the RGB color space used at this time, the sRGB color space is the most general, but in addition, the NTSC-RGB color space having a wider color gamut than the sRGB color space may be selected. When data stored in the RGB color space is stored in a memory card, it is converted to a YCbCr color space having a color space characteristic suitable for the JPEG format, which is a format for compressing and storing data. When the image data is stored in the JPEG format, the image data expressed in the RGB color space is subjected to an operation using an inverse matrix of a matrix S described later to change the color space of the image data into the RGB color space. For example, conversion is performed from the sRGB color space to the YCbCr color space. When converting from the sRGB color space to the YCbCr color space, it is assumed that color values outside the region of the sRGB color space, that is, negative value data as the color values are also converted while being effective.

  The digital still camera 12 used in the image data output system 10 stores image processing control information GI as an image file in the memory card MC in addition to the image data. The image file generated by the digital still camera 12 usually has a file structure according to the digital still camera image file format standard (Exif) in order to maintain compatibility of the image file. Exif file specifications are defined by the Japan Electronics and Information Technology Industries Association (JEITA).

  The schematic structure inside the image file in the case of having a file format according to the Exif file format will be described with reference to FIG. FIG. 3 is an explanatory diagram showing a schematic internal structure of the image file GF stored in the Exif file format. Note that terms such as file structure, data structure, and storage area in this embodiment mean an image of a file or data in a state where the file or data is stored in the storage device.

  The image file GF as an Exif file includes a JPEG image data storage area 101 for storing JPEG image data, and an auxiliary information storage area 102 for storing various auxiliary information related to the stored JPEG image data. The auxiliary information storage area 112 stores shooting time information relating to shooting conditions of a JPEG image such as a shooting color space, shooting date and time, exposure, shutter speed, and the like, and thumbnail image data of a JPEG image stored in the JPEG image data storage area 101. It is stored in TIFF format. The attached information is automatically stored in the attached information storage area 102 when the image data is written to the memory card MC. Further, the attached information storage area 102 includes a Makernote data storage area 103 which is an undefined area released to the DSC maker, and the DSC maker causes the Makernote data storage area 103 to store arbitrary information. be able to. Note that, as is well known to those skilled in the art, tags are used in Exif format files to specify each data.

  The Makernote data storage area 103 also has a configuration capable of identifying data stored by a tag. In the present embodiment, an image for controlling image processing in the color printer 20 is provided in the area with a tag of PrintMatching. Processing control information GI is stored.

  The image processing control information GI is information for designating an image output condition so that an optimal image output result can be obtained in consideration of a color reproduction characteristic and an image output characteristic of an output device such as the color printer 20. The information stored as the image processing control information GI includes, for example, parameters related to a gamma correction value, a parameter related to a target color space, the use of a negative value, contrast, color balance adjustment, sharpness, and color correction. I have. Among them, the gamma correction value, the color space, the parameter regarding the use of the negative value, and mainly the information for faithfully reproducing the color characteristics of the subject, and the remaining parameters mainly realize the desired color reproduction. Information. In addition, a negative value means a color specification value (color value) exceeding a defined area of a predetermined RGB color space, in this embodiment, an sRGB color space, and means a positive value and a negative value exceeding 256. A more detailed description of the negative value will be described later.

  The image file GF generated by the digital still camera 12 is sent to the color printer 20 via, for example, the cable CV, the computer PC, or the cable CV. Alternatively, the image file is transmitted to the color printer 20 through a computer PC to which a memory card MC mounted on the digital still camera 12 is connected, or by directly connecting the memory card MC to the printer 20. You. The following description is based on the case where the memory card MC is directly connected to the color printer 20.

B. Configuration of image output device:
The schematic configuration of the image output device according to the first embodiment, that is, the color printer 20, will be described with reference to FIG. FIG. 4 is a block diagram illustrating a schematic configuration of the color printer 20 according to the first embodiment.

  The color printer 20 is a printer capable of outputting a color image and, for example, ejects four color inks of cyan (C), magenta (M), yellow (Y), and black (K) onto a print medium. The printer is an inkjet printer that forms an image by forming a dot pattern on the substrate, or an electrophotographic printer that forms an image by transferring and fixing a color toner on a print medium. As the color ink, in addition to the above four colors, light cyan (light cyan, LC), light magenta (light magenta, LM), and dark yellow (dark yellow, DY) may be used.

  As shown, the color printer 20 drives a print head 211 mounted on a carriage 21 to eject ink and form dots, and reciprocates the carriage 21 in the axial direction of a platen 23 by a carriage motor 22. The control circuit 30 includes a mechanism for causing the print paper P to be conveyed by the paper feed motor 24, and a control circuit 30. The mechanism for reciprocating the carriage 21 in the axial direction of the platen 23 is an endless drive between a carriage shaft 22 and a slide shaft 25 that slidably holds the carriage 21 erected in parallel with the shaft of the platen 23. It is composed of a pulley 27 on which a belt 26 is stretched, a position detection sensor 28 for detecting the origin position of the carriage 21, and the like. The mechanism for transporting the printing paper P includes a platen 23, a paper feed motor 24 for rotating the platen 23, a paper feed auxiliary roller (not shown), and a gear train for transmitting the rotation of the paper feed motor 24 to the platen 23 and the paper feed auxiliary roller. (Not shown).

  The control circuit 30 appropriately controls the movements of the paper feed motor 24, the carriage motor 22, and the print head 211 while exchanging signals with the operation panel 29 of the printer. The printing paper P supplied to the color printer 20 is set so as to be sandwiched between the platen 23 and the paper feed auxiliary roller, and is fed by a predetermined amount according to the rotation angle of the platen 23.

  An ink cartridge 212 and an ink cartridge 213 are mounted on the carriage 21. The ink cartridge 212 contains black (K) ink, and the ink cartridge 213 contains other inks, namely, cyan (C), magenta (M), yellow (Y), and light cyan (LC). ), Light magenta (LM), and dark yellow (DY).

  Next, the internal configuration of the control circuit 30 of the color printer 20 will be described with reference to FIG. FIG. 5 is an explanatory diagram showing the internal configuration of the control circuit 30 of the color printer 20. As shown in the figure, inside the control circuit 30, a peripheral device I / O for exchanging data with the CPU 31, the PROM 32, the RAM 33, the PCMCIA slot 34 for acquiring data from the memory card MC, the paper feed motor 24, the carriage motor 22, and the like. A unit (PIO) 35, a timer 36, a driving buffer 37, and the like are provided. The drive buffer 37 is used as a buffer that supplies a dot on / off signal to the ink ejection heads 214 to 220. These are connected to each other via a bus 38 so that data can be exchanged with each other. The control circuit 30 also includes an oscillator 39 that outputs a drive waveform at a predetermined frequency, and a distribution output device 40 that distributes the output from the oscillator 39 to the ink ejection heads 214 to 220 at a predetermined timing.

  The control circuit 30 reads the image file GF from the memory card MC, analyzes the image processing control GI, and executes image processing based on the analyzed image processing control information GI. The control circuit 30 outputs dot data to the drive buffer 37 at a predetermined timing while synchronizing with the movements of the paper feed motor 24 and the carriage motor 22. The detailed flow of image processing executed by the control circuit 30 will be described below.

C. Image processing in the color printer 20:
Image processing in the color printer 20 according to the first embodiment will be described with reference to FIGS. FIG. 6 is a flowchart illustrating a processing routine of a printing process in the color printer 20 according to the first embodiment. FIG. 7 is a flowchart showing the flow of image processing in the color printer 20.

  When the memory card MC is inserted into the slot 34, the control circuit 30 (CPU 31) of the printer 20 reads the image file GF from the memory card MC, and temporarily stores the read image file GF in the RAM 33 (Step S100). The CPU 31 searches the attached information storage area 102 of the read image file GF for a PrintMatching tag indicating the image processing control GI at the time of image processing of the image data (step S110). When the PrintMatching tag has been searched for and found (Step S120: Yes), the CPU 31 acquires and analyzes the image processing control information GI including the use of the negative value (Step S130). The CPU 31 executes image processing described later in detail based on the analyzed image processing control information GI (step S140), and prints out the processed image data (step S150).

  If the CPU 31 has not been able to search or find the PrintMatching tag (step S120: No), the CPU 31 acquires from the ROM 32 the color space information previously held as a default value by the color printer 20, for example, information on the sRGB color space. Normal image processing without using a negative value is executed (step S160). CPU 31 prints out the processed image data (step S150), and terminates the processing routine.

  The image processing executed in the color printer 20 will be described in detail with reference to FIG. The control circuit 30 (CPU 31) of the color printer 20 extracts the image data GD from the read image file GF (Step S200). As described above, the digital still camera 12 stores the image data as a JPEG format file. In the JPEG file, the color space (sRGB color space) of the generated image data is changed to YCbCr in order to increase the compression ratio. The image data is stored after being converted to a color space.

  However, since personal computers and printers can usually handle only image data expressed in the RGB color space, the color space of image data expressed in the YCbCr color space is converted to the RGB color space. There is a need to.

  The CPU 31 executes a 3 × 3 matrix operation S to convert YCbCr image data into RGB image data (step S210). The matrix operation S is an operation expression defined by the JPEG File Interchange Format (JFIF) standard for converting the color space of image data from the YCbCr color space to the RGB color space. It is.

  When the matrix operation S is performed, the image data in the RGB color space obtained after the conversion is converted into a first positive color value (color specification) representing a defined area in a predetermined RGB color space, for example, an sRGB color space. Value), and may have a second positive color value (color specification value) exceeding the area of (value) or a negative color value (color specification value) having a negative value in the RGB color space. Therefore, in the present embodiment, whether or not to use the second positive color value and the negative color value is specified in the image processing control information GI. Here, the sRGB color space is a color space defined as a standard color space of a monitor, and is a color space generally used in an operating system (OS) on the assumption that image data is output on a monitor. It is. Also, an 8-bit data capacity is assigned to each of the RGB components corresponding to the definition area of the sRGB color space. Therefore, conventionally, a color value exceeding the defined area of the sRGB color space has been clipped, that is, rounded (cut off) in the defined area of the sRGB color space.

  In general, it is said that the digital still camera 12 uses the sRGB color space. However, the digital still camera 12 may not strictly follow the definition of the sRGB color space. Therefore, by executing the matrix operation S, when the color space of the image data GD is converted to the RGB color space used in the digital still camera 12, there is a color value exceeding the defined area of the sRGB color space. Could be.

  In the present embodiment, image processing is executed without cutting off color values exceeding the defined area of the sRGB color space. When the use of a negative value is specified in the image processing control information GI, the CPU 31 converts the image data in the RGB color space obtained after the conversion into a second positive color value or a negative color value (color specification value). ), The second positive color value and the negative color value are treated as valid values without being clipped, that is, rounded down in the definition area of the sRGB color space, and the first positive color value Save as is with the value. Therefore, when the image data GD has the second positive color value or the negative color value, the RGB color space having the wider definition region than the sRGB color space (used in the digital still camera 12). The image data GD is represented in an RGB color space). At this time, since the image data GD has a color value in an area beyond the defined area of the sRGB color space, the data capacity becomes larger than 8 bits.

  An image that effectively handles negative values will be described with reference to FIG. FIG. 8 is an explanatory diagram for expressing the color space area in two dimensions in order to explain the meaning of effectively handling image data outside the defined area (EA) of the sRGB color space. In the negative value validation processing in the present embodiment, the image data also has data values outside the defined area (EA) of the RGB color space shown in FIG. 8 in addition to data values within the defined area of the RGB color space. I do. In the example of FIG. 8, the undefined region when the image data is generated in the NTSC RGB color space is illustrated, but the color space in which the image data is generated is not limited to this. Note that the definition area of the RGB color space is represented by coordinates (R, G, B) when each of the R component, the G component, and the B component is taken as a coordinate axis. Has the second positive color value and the negative color value, it means that any component of (R, G, B) takes the second positive color value and the negative color value. .

  In the sRGB color space, image data is represented by 256 gradations (8 bits) for each of the R component, the G component, and the B component. It is represented by an integer value of 255. The second positive color value area is represented by an integer value of 256 or more, and the negative color value area is represented by a negative integer value of -1 or less.

  The fact that the converted image data in the RGB space has not only the first color value but also the second positive color value and the negative color value in comparison with the sRGB color space means that the digital still camera 12 For example, as described above with reference to FIG. 8, when the image data is generated, it means that an RGB color space wider than the sRGB color space is used. As described above, the sRGB color space has a color space characteristic optimized for the color characteristic of the CRT display, and is generally a color space that can be photographed by the digital still camera 12 or can be printed by a printer. It is known that a complex color space cannot be sufficiently expressed.

  Therefore, such a second positive color value and a negative color value cannot be represented in color in the sRGB color space, but are larger in the RGB color space than the sRGB color space, or the second positive color value and the negative color value. In some cases, a color can be represented by re-converting to an RGB color space that includes at least one of the negative color values in its definition area. Therefore, in the color printer 20 according to the present embodiment, all information including the second positive color value and the negative color value included in the image data converted from the YCbCr color space to the RGB color space is regarded as valid. Treat and retain. Note that when image data is generated by the digital still camera 12, if data values outside the defined area of the sRGB color space have been rounded, the second positive It goes without saying that color values and negative color values cannot be obtained.

  The CPU 31 executes the gamma correction and the matrix operation M on the image data in the RGB color space thus obtained (step S220). The process executed here is a process executed according to the color space information in the image processing control information GI. When performing the gamma correction, the CPU 31 refers to the gamma correction value in the above-described parameters, and executes the gamma conversion process on the video data using the set gamma correction value (the unique value of the DSC). I do.

In executing the gamma correction, if the use of a negative value is specified by the image processing control information GI, the CPU 31 determines in a region where the image data takes the first and second color values as shown in FIG. The first gamma correction value γ1 (set gamma correction value) is used, and the second gamma correction value γ2 smaller than the first gamma correction value is used in an area where the image data takes a negative color value. . The second gamma correction value γ2 is further divided into γ2r for the R component, γ2g for the G component, and γ2b for the B component. FIG. 9 shows a first gamma characteristic line L1 corresponding to a first gamma correction value γ1 used for gamma correction and second gamma characteristic lines L2r, L2g corresponding to second gamma correction values γ2r, γ2g, γ2b. , L2b. Note that, for ease of description, the R component will be typically described as an example, except for the second gamma characteristic line L2. The first gamma characteristic line L1 is expressed as Rt '= (Rt) ^γ1 for the R component, and the second gamma characteristic line L2 is expressed as Rt' = − (− Rt) ^γ2r .

  In general, since the YCbCr color space and the RGB color space are related by the above equation using the matrix operation S, the color system of the YCbCr color space (0 to Y to 255, -128 to Cb to 127,- When the image data represented by 128 to Cr to 127) is expressed by the color system of the RGB color space, the area T of the positive color value of the R, G, and B components always has the area of 0 to 255. However, since the negative color value area T / 2 is originally an area where no expression is planned, it tends to be narrower than the positive color value area T. Therefore, when the first gamma correction value γ1 similar to the positive color value is used as the gamma correction value for the negative color value, as shown in FIG. 9, the negative color value region R′1 after the gamma correction becomes Only a region (range) smaller than the negative color value region R1 before the gamma correction can be held, and the negative color value region to be used cannot be effectively used. Under such conditions, in order to secure a wide color space provided by the negative color values of the R, G, and B components on the XYZ color space, a gamma correction value γ for the negative color value is used for the positive color value. Using a small second gamma correction value γ2 (for example, 1.5) different from the first gamma correction value γ1 (for example, 2.2) of Rt ′, Gt after gamma conversion (after correction) ', Bt' range can be extended.

  In other words, even at the time of shooting, by using a different smaller value as the gamma correction value for the positive color value as the gamma correction value for the negative color value, and by using the respective gamma correction values at the time of outputting image data, The image data can be expressed in a wider range, the saturation of the output image data is improved, and the vivid colors of the actual subject can be reproduced.

  When the gamma correction value γ> 1.0, the inclination at the origin is 0, and the first gamma characteristic line L1 and the second gamma characteristic line L2r are smoothly and continuously connected at the joint (origin). It is. As a result, image data (image output result) having a smooth gradation value change is obtained without occurrence of a gradation jump caused by a joint between the first gamma characteristic line L1 and the second gamma characteristic line L2r. be able to.

  Since the R component, the G component, and the B component can take different negative color value regions, the second gamma correction value γ may be changed according to the size of the negative color value region of each of the RGB components. . As can be read from FIG. 10 described later, for example, when the color value area expanded in the order of R component> B component> G component becomes large, as shown in FIG. 9, the second gamma correction for the R component The order of the value γ2r <the second gamma correction value γ2b for the B component γ2b <the second gamma correction value γ2g for the G component The second gamma correction value γ2 may be increased. In such a case, by performing the appropriate gamma correction in the range of the color value area that can be extended, the negative color value area can be effectively used. As a result, the image data can be expressed in a wider range, and the saturation of the output result of the image data can be improved.

  The matrix operation M is an operation for converting an RGB color space into an XYZ color space. When the matrix operation M is executed, the CPU 31 refers to the ColorSpace tag and executes the matrix operation using the matrix (M) corresponding to the written color space in order to reflect the color space at the time of generating the image data. I do. At this time, a color space such as an sRGB color space or an NTSC color space may be used. Here, the reason that the color space information described in the ColorSpace tag is reflected via the XYZ color space is that the XYZ color space is an absolute color space, and the device-independent colors that do not depend on devices such as a DSC and a printer. Because it is space. By always taking the same value at the XYZ color space level when converting the color space, device-independent color matching can be performed. The matrix operation M is an operation expression shown below.

  The color space regions of the visible region (VA), sRGB (SR), NTSC (NS), and wRGB (WR) on the RGB color space are as shown in FIG. As can be understood from FIG. 10, the sRGB color space has the narrowest color space region, and the NTSC color space region and the wRGB color space region have a wider color space region than the sRGB color space region.

  The color space of the image data GD obtained after the execution of the matrix operation M is the XYZ color space. Conventionally, the color space used for image processing in a printer or a computer is fixed to sRGB, and the color space of the digital still camera 12 cannot be effectively used. On the other hand, in the present embodiment, the color space at the time of generating the image data described in the image processing control information GI of the image file GF is set as the target color space, and the matrix operation M is performed in accordance with the set color space. A printer (printer driver) that changes the matrix (M) used for (1) is used. Therefore, even when the digital still camera 12 is one of the color characteristics of the RGB color space and generates the image data in the NTSC color space having a larger space than the sRGB color space, the color space in which the image data is generated is also used. , And correct color reproduction can be realized.

The CPU 31 executes a process of converting the color space of the image data GD from the XYZ color space to the wRGB color space, that is, the matrix operation N ⁻¹ and the inverse gamma correction in order to perform the image adjustment based on the arbitrary information (step). S230). Note that the wRGB color space is a color space wider than the sRGB color space as shown in FIG. 10, and the second positive color value and the negative color value that are not included in the definition area and are not represented in the sRGB color space are also: It can be treated as a representable color value included in the definition area of the wRGB color space. When performing the inverse gamma correction, the CPU 31 refers to the gamma correction value of the color printer 20 in the above-described parameters, and uses the inverse of the set gamma correction value to perform inverse gamma correction on the video data. Execute the conversion process. When executing the matrix operation N ⁻¹ , the CPU 31 executes the matrix operation using the matrix (N ⁻¹ ) corresponding to the conversion from the ROM 31 to the wRGB color space. The matrix operation N- ¹ is an operation expression shown below.

The color space of the image data GD obtained after execution of the matrix operation N- ¹ is a wRGB color space. As described above, the wRGB color space is a color space wider than the sRGB color space, and originally corresponds to the RGB color space that can be expressed by the digital still camera 12.

  CPU 31 executes automatic image adjustment for characterizing the image (step S240). The process executed here is a process executed according to information related to the image quality in the image processing control information GI. When performing automatic image adjustment, the CPU 31 refers to parameter values such as brightness and sharpness from the above-described parameters, and performs image adjustment on video data using the set parameter values. I do. When an automatic adjustment parameter is specified, another parameter value arbitrarily specified is reflected based on the parameter value specified by the automatic adjustment parameter.

  Even when these image quality adjustment parameters are not specified in the image processing control information GI of the image file GF, only the automatic adjustment parameters are automatically added on the digital still camera 12 side. Image adjustment is performed according to the automatic adjustment parameter value.

  The CPU 31 executes a wRGB color conversion process and a halftone process for printing (step S250). In the wRGB color conversion process, the CPU 31 refers to a lookup table (LUT) for conversion into a CMYK color space corresponding to the wRGB color space stored in the ROM 32, and changes the color space of the image data from the wRGB color space to the CMYK. Change to color space. That is, the image data composed of the R, G, and B gradation values is converted into data of gradation values of six colors, for example, C, M, Y, K, LC, and LM, to be used in the printer 20.

  In the halftone process, color-converted image data is received, and a tone number conversion process is performed. In the present embodiment, the image data after the color conversion is expressed as data having 256 gradation widths for each color. On the other hand, the color printer 20 according to the present embodiment can take only one of the states of “form dots” and “do not form dots”. That is, the printer 20 of the present embodiment can locally express only two gradations. Therefore, image data having 256 gradations is converted into image data expressed in two gradations that can be expressed by the color printer 20. As typical methods of the binarization (binarization) processing, there are a method called an error diffusion method and a method called an organized dither method.

  In the color printer 20, prior to the color conversion processing, if the resolution of the image data is lower than the printing resolution, linear interpolation is performed to generate new data between adjacent image data, and conversely, if the resolution is higher than the printing resolution. Performs a resolution conversion process of converting the resolution of image data into a print resolution by thinning out data at a fixed rate. In addition, the color printer 20 executes an interlace process of rearranging the image data converted into a format representing the presence or absence of dot formation into an order to be transferred to the color printer 20.

  In the present embodiment, all image processing is executed in the color printer 20 and a dot pattern is formed on a print medium in accordance with the generated image data. However, all or a part of the image processing is executed on the computer PC. You may do it. This case is realized by providing the image data processing application installed on the hard disk or the like of the computer PC with the image processing function described with reference to FIG. The image file GF generated by the digital still camera 12 is provided to the computer PC via the cable CV or via the memory card MC. On the computer PC, an application is started by a user's operation, and reading of the image file GF, analysis of the image processing control information GI, and conversion and adjustment of the image data GD are executed. Alternatively, by detecting the insertion of the memory card MC, or alternatively, by detecting the insertion of the cable CV, the application starts automatically, reads the image file GF, analyzes the image processing control information GI, Conversion and adjustment of the image data GD may be automatically performed.

  As described above, according to the image processing in the color printer 20 according to the first embodiment, the second positive color value and the negative color value generated when the color space of the image data is converted from the YCbCr color space to the RGB color space. Can be used effectively for image processing. In addition, the color printer 20 includes a CMYK color space conversion table corresponding to a wRGB color space wider than the sRGB color space. Therefore, the color values generated by the digital still camera 12 existing outside the defined area of the sRGB color space can be effectively handled, and the color values existing outside the defined area of the sRGB color space can be used to achieve higher saturation. Can be obtained. In other words, a printing result with higher saturation can be obtained by using a color value that cannot be expressed because it exists outside the defined area in the sRGB color space.

  The image processing in the color printer 20 can be executed by reflecting the color space information described by the ColorSpace tag in the image processing control information GI in the image file GF. Therefore, the image data can be processed in accordance with the color space characteristics specified by the digital still camera 12, and the difference between the photographing result of the digital still camera 12 and the output result of the color printer 20 due to the difference in color space can be reduced. Can be prevented. Further, the color reproduction capability of the digital still camera 12 can be correctly reproduced.

D. Other embodiments:
Image processing in the color printer 20 may be executed as shown in FIG. FIG. 11 is a flowchart illustrating image processing in the color printer 20 according to the second embodiment. In the present embodiment, when changing the color space characteristics from the sRGB color space to the wRGB color space, the matrix operation M and the matrix operation N ^-1 are set as one matrix operation (MN ^-1 ) (step S320), and the image processing speed is increased. It is trying to make it.

The image processing in the color printer 20 may be executed as shown in FIG. FIG. 12 is a flowchart illustrating image processing in the color printer 20 according to the third embodiment. In the present embodiment, automatic image adjustment is first performed on image data expressed in the YCbCr color space (step 410). Subsequently, a matrix S operation (step S420), a matrix M operation (step S430), and a matrix N ^-1 operation (step S440) are performed on the image data on which the automatic image adjustment has been completed, to convert the color space. Execute sequentially.

  In the first to third embodiments, the image processing is executed by the color printer 20, and when the use of a negative value is specified in the image processing control information GI, the negative value of the image data and the second Image processing using a positive value has been performed. On the other hand, in the fourth embodiment, the image processing is executed by the personal computer PC, and the operator who executes the image processing specifies whether or not the negative value is used. The image processing executed by the personal computer PC will be described with reference to FIG. FIG. 13 is a flowchart showing a flow of image processing in the personal computer PC according to the fourth embodiment.

  When the operator instructs to read the image file GF, the personal computer PC reads the image file GF from the memory card MC and temporarily stores the read image file GF in the RAM 33 (step S500). The personal computer PC determines whether or not an instruction to use a negative value has been input by the operator (step S510). When an instruction to use a negative value has been input (step S520: Yes), the personal computer PC executes image processing using the negative value and the second positive value included in the image data GD (step S520). S530), this processing routine ends.

  If the instruction to use the negative value has not been input (step S520: No), the personal computer PC clips the negative value and the second positive value included in the image data GD into the predetermined RGB color gamut. The value and the second positive value are discarded, image processing is performed on the image data GD (step S540), and the processing routine ends. As described above, if the operator can specify whether or not to use a negative value during image processing, the image processing using the negative value included in the image data GD can be performed on the image file GF having no PrintMatching tag. Since the image processing can be executed, an image with high saturation can be obtained as a result of the image processing.

  In the above embodiments of the image processing, the color printer 20 is used as the output device, but a display device such as a CRT, an LCD, a projector, or the like may be used as the output device. In such a case, an image processing program (display driver) for executing the image processing described with reference to FIG. 7 and the like is executed by the display device as the output device. Alternatively, when a CRT or the like functions as a display device of a computer, the computer executes an image processing program. However, the finally output image data has an RGB color space instead of a CMYK color space.

  In such a case, the display result on the display device such as the CRT is designated by the image file GF in the same manner as the print result via the color printer 20 can reflect the color space of the image data generated by the digital still camera 12. can do. Therefore, by providing the image processing control information GI of the image file GF with parameters suitable for a display device such as a CRT, and by providing parameters optimized for the display characteristics of each display device, digital still images can be obtained. The image data GD generated by the camera 12 can be displayed more accurately.

  In the first embodiment, the image processing control information GI is stored in the image file GF together with the image data GD, but may be stored in the memory card MC as a file separate from the image data GD.

  In each of the above embodiments, when the image processing control information GI is detected and an instruction to use a negative value is specified, or when an operator or the like instructs to use a negative value, the negative value included in the image data GD is included. The image processing is executed using the value and the second positive value. However, the image processing using the negative value and the second positive value may be executed from the beginning without receiving these designations and instructions. In such a case, if the image data GD includes a negative value or the like, an image processing result reflecting the negative value or the like can be obtained. If the image data GD does not include a negative value or the like, a normal An image processing result can be obtained.

  As described above, the image data output device according to the present invention has been described based on some examples. However, the above-described embodiments are for facilitating understanding of the present invention, and the present invention is not limited to the embodiments. It does not do. The present invention can be modified and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

  In the first embodiment, the process of effectively handling the second positive color value and the negative color value at the time of the matrix S operation and the process of reflecting the color space information designated at the time of the matrix M operation are simultaneously executed. However, these processes need not be performed simultaneously. For example, the color space at the time of the matrix M operation may be fixed to the wRGB space, and only the process of effectively handling the second positive color value and the negative color value at the time of the matrix S operation may be executed. In such a case, for example, it is possible to express a color outside the defined area of the sRGB color space that can be expressed as the digital still camera 12 but could not be expressed in the sRGB color space, and the saturation of the output image can be reduced. Can be improved.

  Also, it is possible to execute processing for reflecting the color space information at the time of shooting or designated at the time of matrix M calculation without performing the processing using the second positive color value and the negative color value at the time of matrix S calculation. good. In such a case, it is possible to correctly interpret the color space at the time of image data generation at the time of image processing, and to realize correct color reproduction. Therefore, it is possible to execute a device-independent color space conversion process that is not affected by a device-specific color space such as an input device and an output device. As a result, an output result similar to the output result of the image data obtained at the time of shooting can be obtained from the output device.

  Further, in the above embodiment, the use or non-use of the negative value is specified by the image processing control information GI. However, the gamma correction value for the positive value and the gamma correction value for the negative value are specified without specifying the use of the negative value. May be specified by the image processing control information GI. A process that becomes a problem when the image data GD has a negative value is a gamma correction process. Therefore, by using the gamma correction value to be used for the gamma correction process for positive data and negative data, it is possible to execute the image processing without having to specify whether to use a negative value in the image processing.

Further, the illustrated parameters are merely examples, and the invention according to the present application is not limited by these parameters. Further, the values of the matrices S, M, and N ^-1 in each mathematical expression are merely examples, and it goes without saying that the values can be appropriately changed depending on the target color space, the color space available in the color printer 20, and the like. .

  In each of the above embodiments, the digital still camera 12 has been described as the image file generating device. However, a scanner, a digital video camera, or the like may be used. When a scanner is used, the designation of basic information and arbitrary information of the image file GF may be executed on the computer PC, or a preset button in which setting information is pre-assigned on the scanner for setting information, A display screen for setting and a setting button may be provided so that the scanner can be executed alone.

  The color spaces used in the above embodiments are merely examples, and other color spaces may be used. In any case, the image data generated by the image data generation device such as the digital still camera 12 may be output by reflecting the color space of the image data generation device.

  In the first embodiment, an Exif format file has been described as an example of the image file GF, but the format of the image file according to the present invention is not limited to this. That is, any image file that contains at least image data to be output by the output device and information on the color space used in the image data generation device such as the digital still camera 12 may be used. With such a file, it is possible to reduce a difference between an output image of the image data generated by the image data generating device (an image display obtained via a monitor or the like) and an output image of the output device. .

  The color printer 20 according to the first embodiment is merely an example, and the configuration is not limited to the contents described in each embodiment. The color printer 20 only needs to analyze at least the image processing control information GI of the image file GF and output (print) an image in accordance with the described or specified color space information.

  In the image file GF including the image data and the image processing control information GI, association data for associating the image processing control information GI is generated, and the image data and the image processing control information GI are stored in independent files. However, a file that can associate the image data with the image processing control information GI by referring to the association data at the time of image processing is also included. In such a case, although the image data and the image processing control information GI are stored in separate files, at the time of the image processing using the image processing control information GI, the image data and the image processing control information GI cannot be integrated. And functions in the same manner as when stored in the same file. That is, the mode in which the image data and the image processing control information GI are used in association with each other at least at the time of the image processing is included in the image file GF in the present embodiment. Furthermore, moving image files stored on optical disk media such as CD-ROM, CD-R, DVD-ROM, and DVD-RAM are also included.

  In the above embodiment, the image file is generated using the digital still camera 20, but may be generated using a digital video camera. When generated by a digital video camera, for example, an image file storing still image data and output control information or a moving image file including moving image data in MPEG format and output control information is generated. You. When this moving image file is used, output control according to the output control information is performed on all or some frames of the moving image.

FIG. 1 is an explanatory diagram illustrating an example of an image data output system to which an image output device according to a first embodiment can be applied. FIG. 2 is a block diagram illustrating a schematic configuration of a digital still camera capable of generating an image file (image data) output by the image output device according to the first embodiment. FIG. 3 is an explanatory diagram showing a schematic internal structure of an image file GF stored in an Exif file format. FIG. 2 is a block diagram illustrating a schematic configuration of a color printer 20 according to the first embodiment. FIG. 2 is an explanatory diagram showing an internal configuration of a control circuit 30 of the color printer 20. 4 is a flowchart illustrating a processing routine of a printing process in the color printer 20 according to the first embodiment. 6 is a flowchart illustrating a flow of image processing in the color printer 20 according to the first embodiment. FIG. 3 is an explanatory diagram illustrating a two-dimensional representation of a color space area in order to explain the meaning of effectively handling image data outside a defined area (EA) of an RGB color space. The first gamma characteristic line L1 corresponding to the first gamma correction value γ1 and the second gamma characteristic lines L2r, L2g, L2b corresponding to the second gamma correction values γ2r, γ2g, γ2b used for gamma correction It is explanatory drawing shown exemplarily. FIG. 3 is an explanatory diagram showing a color space region of a visible region (VA), sRGB (SR), NTSC (NS), and wRGB (WR) on an RGB color space. 9 is a flowchart illustrating image processing in a color printer 20 according to a second embodiment. 9 is a flowchart illustrating image processing in a color printer 20 according to a third embodiment. 15 is a flowchart illustrating a flow of image processing in a personal computer PC according to a fourth embodiment.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 ... Image data output system 12 ... Digital still camera 121 ... Optical circuit 122 ... Image acquisition circuit 123 ... Image processing circuit 124 ... Control circuit 126 ... Selection / decision button 14 ... Display 20 ... Color printer 21 ... Carriage 211 ... Print head 212 ... Ink cartridge 213 ... Ink cartridge 214-220 ... Ink ejection head 22 ... Carriage motor 23 ... Platen 24 ... Paper feed motor 25 ... Sliding shaft 26 ... Drive belt 27 ... Pulley 28 ... Position detection sensor 29 ... Operation panel 30 ... Control circuit 31: arithmetic processing unit (CPU)
32: Programmable read only memory (PROM)
33 Random access memory (RAM)
34 PCMCIA slot 35 Peripheral device input / output unit (PIO)
36 ... Timer 37 ... Drive Buffer 38 ... Bus 39 ... Oscillator 40 ... Distribution Output Device GF ... Image File (Exif File)
101: JPEG image data storage area 102: Additional information storage area 103: Makernote storage area MC: Memory card

Claims (31)

An image processing apparatus that performs image processing using image data and usage information associated with the image data, indicating whether to use information outside a predetermined color space area,
Image data capturing means for capturing the image data,
Usage information obtaining means for obtaining the usage information associated with the image data,
Determining means for determining whether to use information outside the area of the predetermined color space based on the obtained use information,
If it is determined that the out-of-area information is used, image processing of the image data including a color conversion process to a wide-area color space having a wide definition area capable of including the out-of-area information in the definition area is performed. An image processing apparatus comprising: an image processing unit. The image processing apparatus according to claim 1,
If it is determined that the out-of-area information is not used, the image processing unit performs image processing of the image data via a predetermined color space having a defined area equivalent to the predetermined color space. An image processing apparatus characterized by the above-mentioned. In the image processing device according to claim 1 or 2,
The image data is defined by a first color space;
The image data capturing means converts a color space of the captured image data from the first color space to a second color space;
The image processing apparatus, wherein the image processing unit converts a color space of image data defined by the second color space into a third color space using the out-of-region color values. The image processing device according to claim 3,
The first color space is a YCbCr color space,
The second color space is a first RGB color space;
The image processing apparatus according to claim 1, wherein the third color space is a second RGB color space having a larger definition area than the first RGB color space. The image processing apparatus according to claim 4,
The image processing device, wherein the second RGB color space is an sRGB color space. The image processing apparatus according to claim 4,
The image processing apparatus according to claim 3, wherein the third color space is a CIELAB color space instead of the second RGB color space. The image processing apparatus according to claim 1, wherein the image data includes a first positive colorimetric value that is a colorimetric value within a definition area of the predetermined color space, and a first colorimetric value outside the definition area of the predetermined color space. A color value that includes at least one of a second positive color value and a negative color value, and is represented by a first color space;
The image data capturing unit changes the color space of the image data from the first color space to a second color space using the first and second positive color values and the negative color values. An image processing device for converting. The image processing apparatus according to claim 7,
The image processing means uses a first gamma correction value when the image data has the first and second positive colorimetric values, and uses a first gamma correction value when the image data has a negative colorimetric value. An image processing apparatus comprising: a gamma correction unit configured to perform gamma correction on the image data using a second gamma correction value different from the first gamma correction value. The image processing apparatus according to claim 8,
The image processing apparatus according to claim 1, wherein the second gamma correction value is smaller than the first gamma correction value. The image processing apparatus according to claim 7,
The image processing means converts the image data represented by the second color space and including the first positive color value, the second positive color value, and the negative color value. And converting the data into a third color space wider than the second color space and including at least one of the second positive color value and the negative color value in its defined area. Image processing device. The image processing apparatus according to claim 8,
The first color space is an RGB color space represented by an R component, a G component, and a B component,
The second gamma correction values each have a different second gamma correction value for the R component, a second gamma correction value for the G component, and a second gamma correction value for the B component. An image processing apparatus characterized by the above-mentioned. The image processing apparatus according to any one of claims 3 to 11,
The conversion of the color space of the image data from the first color space to the second color space by the image data capturing means is performed by a first matrix operation on the image data represented by the first color space. Executed by the process,
The conversion of the color space of the image data from the second color space to the third color space by the image processing means is performed by a second matrix operation process on the image data expressed in the second color space. An image processing apparatus characterized by being executed by: A first positive colorimetric value that is represented by the first color space and is a colorimetric value within the color gamut of the predetermined color space, and a colorimetric value outside the color gamut of the predetermined color space. An image processing apparatus that performs image processing using image data including at least one of a certain second positive color value and a negative color value,
Image data acquisition means for acquiring the image data,
Using the first and second positive colorimetric values and the negative colorimetric values, the color space of the image data from the first color space is wider than the predetermined color space, A color space conversion unit that converts at least one of the color specification value and the negative color specification value into a second color space including the color gamut. The image processing apparatus according to claim 13, further comprising:
The first gamma correction value is used when the image data has the first and second positive color values, and the first gamma correction is used when the image data has a negative color value. An image processing apparatus, comprising: gamma correction means for performing gamma correction on the image data using a second gamma correction value different from the value. The image processing apparatus according to any one of claims 1 to 14, further comprising:
An image processing apparatus comprising: a printing unit that prints the image data on which the image processing has been performed on a print medium. An image processing apparatus according to any one of claims 1 to 15,
The image processing apparatus, wherein the image data and the usage information are stored in the same image file. A program that causes an image output device to output image data using image data and use information indicating whether to use an out-of-region color value that is a color value outside a defined region of a predetermined color space,
A function of capturing the image data,
A function of acquiring the usage information associated with the captured image data,
Based on the obtained use information, a function to determine whether to use the out-of-area color value,
A function of executing image processing of the image data through a color space having a wide defined area that can include the out-of-area color value in the defined area when it is determined that the out-of-area color value is used; ,
A program for realizing, by a computer, a function of outputting the image data subjected to the image processing. The program according to claim 17, wherein
The image data includes a first positive colorimetric value that is a colorimetric value in the definition area of the predetermined color space, and a second positive colorimetric value and a negative colorimetric value that are the colorimetric values outside the area. A value including at least one of the values and represented by the first color space,
The function of taking in the image data includes, in addition to taking in the image data, using the first and second positive colorimetric values and the negative colorimetric values to change the color space of the image data into the first color space. That causes a computer to realize the function of converting the color space from the first color space into the second color space. The program according to claim 18, further comprising:
When the image data has the first positive color specification value, the first gamma correction value is used. When the image data has the negative color specification value, the first gamma correction value is A program for causing a computer to realize a function of performing gamma correction on the image data using a different second gamma correction value. An image data generation device that outputs image data in association with image processing control information that specifies image processing conditions for the image data,
Image data acquisition means for acquiring the image data,
When performing image processing on the image data, an image processing control information generating unit that generates the image processing control information including usage information indicating whether to use information outside a region of a predetermined color space. ,
An image data generating apparatus comprising: an image data output unit configured to output the acquired image data in association with the generated image processing control information. The image data generation device according to claim 20,
The image data generating device outputs the image data stored in the same image file together with the image processing control information. An image data generation device that outputs image data in association with image processing control information that specifies image processing conditions for the image data,
A first positive colorimetric value that is a colorimetric value within a color gamut of a predetermined color space; a second positive colorimetric value that is a colorimetric value outside the color gamut of the predetermined color space; Image data generating means for generating the image data including at least one of the color specification values,
When performing image processing on the image data, usage information indicating whether to use at least one of the second positive color value and the negative color value; and A first gamma correction value to be used when the image data has the first and second positive color values, and a first gamma correction value to be used when the image data has a negative color value. Image processing control information generating means for generating image processing control information including a different second gamma correction value;
An image data generating apparatus comprising: an image data output unit configured to output the generated image data in association with the generated image processing control information. The image data generation device according to claim 22, further comprising:
When performing color space conversion of the image data, the image processing control information includes at least one of the second color value and the negative color value that is wider than the predetermined color space. An image data generation device including a color space conversion characteristic for converting to a color space included in a color gamut. The image data generation device according to claim 22,
The image data generating device outputs the image data stored in the same image file together with the image processing control information. A method of outputting image data using image data represented by a first color space and use information indicating whether information outside a region of a predetermined color space is used,
Acquiring the image data, converting a color space of the acquired image data from the first color space to a second color space,
Determine whether to use the out-of-area information based on the use information,
When it is determined that the out-of-area information is used, the color space of the image data represented by the second color space is converted to a third color space using the out-of-area information,
An image data output method for outputting the converted image data. A method of outputting image data,
Acquiring the image data represented by a first color space, converting the color space of the acquired image data from the first color space to a second color space,
Holding information on the second color space obtained by the conversion, and information outside a region that defines the second color space,
Reflecting the held information, converting the color space of the image data represented by the second color space into a third color space,
An image data output method for outputting the converted image data. The method for outputting image data according to claim 26,
The information of the area that defines the second color space is represented by a first positive area value, and the information outside the area that defines the second color space exceeds the first positive area value. A method of outputting image data, characterized by being represented by a second positive area value and a negative area value. The method for outputting image data according to claim 27, further comprises:
A first gamma correction value is used when the image data has the first positive area value, and a first gamma correction value different from the first gamma correction value when the image data has a negative area value. 2. An image data output method for performing gamma correction on the image data using a gamma correction value of 2. An image processing method of image data,
Acquiring the image data based on a first color space, converting the color space of the acquired image data from the first color space to a second color space,
Holding information inside and outside a region that defines the second color space for the converted image data,
Reflecting the stored information, the image data converted from the color space of the image data represented by the second color space into a third color space having a defined area wider than the second color space. Image processing method. An image processing apparatus that performs image processing on image data,
Image data capturing means for capturing the image data,
Instructing means for instructing whether to use information outside the area of the predetermined color space included in the image data,
When the use of the out-of-area information is instructed, image processing of the image data including a color conversion process to a wide-area color space having a wide definition area capable of including the out-of-area information in the definition area is executed. An image processing apparatus comprising: an image processing unit. The image processing apparatus according to claim 30,
When the use of the out-of-area information is not instructed, the image processing means executes image processing of the image data via a predetermined color space having a defined area equivalent to the predetermined color space. An image processing apparatus characterized by the above-mentioned.

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