JP2008079199A - Print using undeveloped image data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of easily executing printing using undeveloped image data. <P>SOLUTION: A print control device is provided with a print data generating unit for executing development processing for undeveloped image data to generate print data to be supplied to a print executing unit. The development processing includes exposure correction processing to be executed depending on a set exposure correction quantity. Further, the print control device is provided with a display image data adjusting unit for adjusting the gradation characteristics of developed image data for display in which an object represented by the undeveloped image data is expressed, depending on an exposure correcting amount prior to the execution of the development processing, and causing a display unit to display an image represented by the adjusted image data for display. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for performing printing using undeveloped image data.

  A digital still camera (hereinafter also referred to as “camera”) normally performs development processing (digital image processing) on RAW image data to generate developed image data (for example, JPEG image data), and the developed image data Is recorded on the memory card. The RAW image data is obtained by analog-to-digital conversion of light detection values detected by an image sensor (e.g., CCD, CMOS) provided in the camera, and image data for one frame as an aggregate of each pixel data. It is data in which information is recorded as it is, and is undeveloped image data that has not been developed in the camera. In recent years, some cameras can record RAW image data on a memory card. It should be noted that the image file in which the RAW image data is recorded usually includes setting information at the time of shooting.

Japanese Patent Application Laid-Open No. 2001-223979 JP 2004-128809 A JP 2005-63128 A JP 2005-33255 A JP 2003-250053 A JP 2005-175978 A

  However, conventionally, printing using RAW image data has not been considered much, and it has not been possible to easily execute printing using RAW image data.

  The present invention has been made to solve the above-described problems in the prior art, and an object of the present invention is to provide a technique capable of easily executing printing using undeveloped image data.

In order to solve at least a part of the above-described problems, an apparatus of the present invention is a print control apparatus that uses a display unit and a print execution unit,
A print data generation unit that executes development processing on undeveloped image data and generates print data supplied to the print execution unit, wherein the development processing is executed in accordance with a set exposure correction amount. The print data generation unit including an exposure correction process;
Before the development processing is executed, the gradation characteristics of the developed display image data representing the subject represented in the undeveloped image data are adjusted according to the exposure correction amount. A display image data adjusting unit for causing the display unit to display an image represented by the display image data;
It is characterized by providing.

  In this apparatus, since it is possible to generate print data by executing development processing on undeveloped image data, it is possible to easily execute printing even when undeveloped image data is used. Further, in this apparatus, the user can grasp the subject expressed in the undeveloped image data before the development process is executed by confirming the image displayed on the display unit. In particular, in this apparatus, since the gradation characteristics of the display image data are adjusted according to the exposure correction amount, display is performed according to the exposure correction amount before the development processing including the exposure correction processing is executed. The brightness of the image displayed on the screen can be changed.

In the above apparatus,
The print data generation unit executes the development processing to generate developed print image data, generates the print data using the print image data,
The display image data adjusting unit adjusts the exposure image data according to the exposure correction amount so that the gradation characteristic of the display image data approaches the gradation property of the print image data according to the exposure correction amount. It is preferable to carry out the adjustment.

  In this way, the user can grasp the brightness of the printed image corresponding to the exposure correction amount before executing the development process by checking the image displayed on the display unit.

In the above apparatus,
The display image data adjustment unit acquires information for specifying a generation device that has generated the display image data, and changes the adjustment processing condition according to the exposure correction amount based on the information. Is preferred.

  The gradation characteristics of the display image data depend on the generation device. For this reason, according to the above, it is possible to appropriately perform the adjustment according to the exposure correction amount according to the gradation characteristics of the display image data that may be different for each generation device.

In the above apparatus,
The display image data adjustment unit may adjust the gradation characteristics of the display image data based on Y = A · X.
Here, X is the gradation value of the display image data when the maximum gradation value that the display image data can take is 1, and Y is the maximum gradation that the adjusted display image data can take. The gradation value of the adjusted display image data when the value is 1, and A is a value corresponding to the exposure correction amount.

Alternatively, in the above device,
The display image data adjustment unit may adjust the gradation characteristics of the display image data based on Y = B · X ^C.
Here, X is the gradation value of the display image data when the maximum gradation value that the display image data can take is 1, and Y is the maximum gradation that the adjusted display image data can take. The gradation values of the adjusted display image data when the value is set to 1, and B and C are values according to the exposure correction amount.

  In this way, adjustment can be performed easily and quickly.

Alternatively, in the above device,
The display image data adjustment unit uses a table prepared in advance based on the gradation characteristics of the printing image data and the gradation characteristics of the display image data according to the exposure correction amount, The gradation characteristics of the display image data may be adjusted.

  In this way, the brightness of the printed image and the brightness of the image displayed on the display unit can be recognized almost the same by the user.

  The present invention can be realized in various forms, for example, a print control device, a printer including the print control device, a print control method, a computer program for realizing the function or method of these devices, and the like The present invention can be realized in the form of a recording medium that records a computer program, a data signal that includes the computer program and is embodied in a carrier wave, and the like.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Printer configuration:
B. Printing process:
C. Exposure compensation processing:
D. Adjustment of display image data:
D-1. First adjustment method:
D-2. Second adjustment method:
D-3. Third adjustment method:
E. Adjustment of display image data according to exposure compensation amount:
E-1. First adjustment method:
E-2. Second adjustment method:
E-3. Third adjustment method:

A. Printer configuration:
FIG. 1 is an explanatory diagram illustrating a printer 200 according to the embodiment. The printer 200 has a direct printing function, that is, a function of performing printing using image data generated by a digital still camera and given through a memory card MC without using a personal computer. In particular, the printer 200 of this embodiment can perform printing using JPEG image data and can perform printing using RAW image data. The JPEG image data is image data (developed image data) that has been subjected to development processing (image generation processing) for viewing in the camera and then compressed into the JPEG format. The RAW image data is RAW format undeveloped image data that has not undergone development processing (image generation processing) in the camera. That is, RAW image data is raw image data obtained by analog-to-digital conversion of light intensity detected by an image sensor (for example, CCD, CMOS, etc.) provided in the camera, and development processing (image generation processing). This is image data before. In the present embodiment, when printing using RAW image data is executed, image data (developed image data) compressed in JPEG format after being subjected to development processing (image generation processing) in the printer 200 is obtained. Generated. In this embodiment, developed data that is JPEG compressed is generated in the printer 200. However, if the memory capacity is sufficiently large, developed image data that is not JPEG compressed may be generated. Good.

  In this embodiment, developed image data in JPEG format that has been subjected to development processing in the camera is also referred to as “JPEG image data”, and developed image data in JPEG format that has been subjected to development processing in the printer is referred to as “image data for printing”. Also called.

  The developed image data and the RAW image data are such that an image expressed by the developed image data can be immediately viewed on a monitor or the like, but an image expressed by the undeveloped image data cannot be immediately viewed. Is different. Development processing is necessary to make an image expressed by undeveloped image data viewable.

  As shown in FIG. 1, the printer 200 includes a CPU 210, an internal storage device 220 such as a ROM or a RAM, a display panel 260, an operation unit 270 such as a button, a print execution unit 280 that executes printing, and an interface unit. (I / F part) 290.

  The I / F unit 290 includes a card slot into which the memory card MC is inserted. The memory card MC stores an image file generated as the subject is photographed by the camera, and the I / F unit 290 reads the image file recorded on the memory card MC.

  FIG. 2 is an explanatory diagram schematically showing the structure of a RAW image file including RAW image data. This RAW image file is created in a data format similar to the Exif (Exchangeable Image File Format) format, and includes a header portion and a data portion as shown in the figure.

  In the header section, additional information such as the manufacturer name and model number of the camera that created the RAW image file, shooting conditions, and shooting date and time are described. Note that the shooting conditions include, for example, a shutter speed at the time of shooting, an aperture value, a white balance setting value, and the like.

  The data portion includes RAW image data and display image data generated at the time of shooting. Note that the same subject (captured image) is represented in the RAW image data and the display image data, and the RAW image data and the display image data are recorded at the same time as shooting. The display image data is, for example, reduced-size JPEG image data that is used when a captured image is simply displayed on a display panel provided in the camera, and has undergone development processing in the camera. The display image data has a relatively small resolution (for example, 640 × 480) that can be displayed on the display panel to express a sufficient resolution and image quality, and is also called screen nail image data.

  Note that the data structure of the RAW image file differs depending on the camera manufacturer and camera model, and the RAW image file may include JPEG image data together with the RAW image data. Also in this case, the same subject (captured image) is expressed in the RAW image data and the JPEG image data, and the RAW image data and the JPEG image data are recorded simultaneously with the shooting.

  Note that the RAW image file may include JPEG image data for display. Also, a RAW image file including RAW image data and a JPEG image file including JPEG image data may be recorded simultaneously with shooting. In this case, the same subject (captured image) is expressed in the two image data. For this reason, the two files are given the same file name and different extensions, for example, “ABCD0123.RAW” and “ABCD0123.JG” so that the two files are clearly related to each other. It is preferable. In this case, JPEG image data is used as display image data corresponding to the RAW image data.

  Although the RAW image file including the RAW image data has been described with reference to FIG. 2, the JPEG image file including the JPEG image data also includes a header portion and a data portion, like the RAW image file. However, in a JPEG image file, instead of RAW image data and display image data, JPEG image data and thumbnail image data having a relatively small resolution (for example, 160 × 120) are usually included in the data portion. include. This file structure is based on the DCE 2.0 standard of the JEITA standard.

  A computer program (printer driver) that functions as the print control unit 230 is stored in the internal storage device 220 (FIG. 1). Note that the function of the print control unit 230 is realized by the CPU 210 executing the computer program. The computer program may be stored in advance in the internal storage device 220 as firmware, or may be provided in a form recorded on a computer-readable recording medium such as a CD-ROM.

  The print control unit 230 includes a processing condition determination unit 240 and a print data generation unit 250, and executes various processes for printing.

  The processing condition determination unit 240 (FIG. 1) includes a first setting unit 242a and a second setting unit 242b, and displays a setting screen to determine processing conditions for printing.

  When printing using JPEG image data is executed, the first setting unit 242a displays a JPEG image print setting screen including a plurality of setting items, and the contents of each item set by the user on the setting screen To get. When the start of printing is instructed by the user, the processing condition determination unit 240 performs processing conditions for printing using JPEG image data based on the contents of each item acquired by the first setting unit 242a. To decide.

  In the present embodiment, the first setting unit 242a displays a reference image indicating a print target in the JPEG image print setting screen. Specifically, the first setting unit 242a generates reference image data representing the reference image by reducing the JPEG image data to be printed.

  When printing using RAW image data is executed, the second setting unit 242b displays a RAW image print setting screen including a plurality of setting items, and the contents of each item set by the user on the setting screen To get. When the start of printing is instructed by the user, the processing condition determination unit 240 performs processing conditions for printing using RAW image data based on the contents of each item acquired by the second setting unit 242b. To decide.

  In the present embodiment, the second setting unit 242b displays a reference image indicating a print target in the RAW image print setting screen. Specifically, the second setting unit 242b uses display image data corresponding to the RAW image data to be printed, that is, display image data included in the same RAW image file as the RAW image data to be printed. Then, reference image data representing the reference image is generated.

  In particular, in the present embodiment, the second setting unit 242b includes a display image data adjustment unit 244. The display image data adjustment unit 244 performs adjustment processing for adjusting the gradation characteristics (tone curve) of the display image data, and generates adjusted display image data (reference image data).

  The print data generation unit 250 includes a development processing unit 252 and a developed image processing unit 254, and generates print data from original image data (JPEG image data or RAW image data).

  The development processing unit 252 is used when printing using RAW image data is performed. The development processing unit 252 performs development processing on the RAW image data, and develops the developed image data in JPEG format (hereinafter referred to as “print image data”). Call). As will be described later, the development processing unit 252 includes optical black correction processing, white balance correction processing, exposure correction processing, pixel interpolation processing, color reproduction processing, RGB-YUV conversion processing, edge enhancement processing, noise removal processing, and tone correction. Processing, JPEG processing, etc. are performed.

  The developed image processing unit 254 generates print data using the developed image data, and supplies the print data to the print execution unit 280. Specifically, when printing using JPEG image data is executed, print data is generated using the JPEG image data. On the other hand, when printing using RAW image data is executed, print data is generated using developed image data (printing image data) in JPEG format generated by the development processing unit 252.

  The developed image processing unit 254 executes various image processes when generating print data. This image processing includes, for example, processing for correcting brightness, processing for detecting the face of a subject person and correcting the face color, processing for correcting so-called red eyes, and the like. Thereafter, the developed image processing unit 254 performs resolution conversion processing, color conversion processing, and halftone processing, as is well known, and generates dot data (print data) indicating a dot formation state. In the color conversion process, R (red), G (green), and B (blue) color components are converted into Y (yellow), M (magenta), C (cyan), and K (black) ink amounts. And a predetermined gradation correction is performed. Printing is performed based on the density information of the ink data.

B. Printing process:
FIG. 3 is a flowchart showing the procedure of the printing process. In step S102, the processing condition determination unit 240 displays a print setting selection screen on the display panel 260 in accordance with an instruction from the user. The user's instruction is performed by the user operating the operation unit 270.

  FIG. 4 is an explanatory diagram showing the print setting selection screen W. As shown in FIG. 4, the selection screen W includes a “JPEG image print setting” selection button B1 and a “RAW image print setting” selection button B2. The selection buttons B1 and B2 are selected by the user operating the operation unit 270.

  When printing using JPEG image data is desired, the user selects the “JPEG image print setting” selection button B1 on the selection screen W in FIG. At this time, the process proceeds to step S112.

  In step S112, the first setting unit 242a of the processing condition determination unit 240 displays a JPEG image print setting screen on the display panel 260.

  FIG. 5 is an explanatory diagram showing a JPEG image print setting screen Wa. As shown in FIG. 5, the setting screen Wa includes selection buttons Ba1 and Ba2 for selecting a print target, a reference image display field Fa for displaying a reference image indicating the selected print target, and execution of printing. And a “print” button BPa. As described above, in the reference image display field Fa, an image is displayed using the reference image data obtained by reducing the JPEG image data. The user operates the selection buttons Ba1 and Ba2 while confirming the reference image displayed in the reference image display field Fa, so that a plurality of JPEG image data included in the plurality of JPEG image files stored in the memory card MC is displayed. Desired JPEG image data can be selected as image data to be printed.

  The setting screen Wa includes various items for determining processing conditions for printing using JPEG image data. Specifically, the setting screen Wa includes an item “printing paper” for selecting the type of printing paper, an item “paper size” for selecting the size of the printing paper, and print quality (high-speed normal image quality mode). Alternatively, an item “print quality” for selecting a low-speed high-quality mode) and an item “red-eye correction” for selecting whether or not red-eye correction is performed are included. In addition, the setting screen Wa includes an item “brightness correction” for selecting whether or not brightness correction is performed and the content, and an item “color correction” for correcting the hue.

  In this embodiment, the content of the item “brightness correction” can be set to any one of “no correction”, “bright”, “dark”, and the like. In the present embodiment, the content of the item “color correction” can be set to any one of “no correction”, “strong redness”, “strong blueness”, and the like. In the setting screen Wa of FIG. 5, it is assumed that the content of the item “brightness correction” and the content of the item “color correction” are set by the user. You may make it set to.

  In the setting screen Wa, when the user operates the operation unit 270, JPEG image data to be printed is selected and the contents of each item are set. Then, the “print” button BPa is selected by the user.

  In step S114, the processing condition determination unit 240 determines processing conditions for printing using JPEG image data based on the contents of each item acquired by the first setting unit 242a.

  On the other hand, when printing using RAW image data is desired, the user selects the “RAW image print setting” selection button B2 on the selection screen W in FIG. At this time, the process proceeds to step S122.

  In step S122, the second setting unit 242b of the processing condition determining unit 240 displays a RAW image print setting screen on the display panel 260.

  FIG. 6 is an explanatory diagram showing a RAW image print setting screen Wb. As shown in FIG. 6, the setting screen Wb includes selection buttons Bb1 and Bb2, a reference image display field Fb, and a “print” button Bpb, as in the setting screen Wa of FIG. As described above, an image is displayed in the reference image display field Fb using the adjusted display image data (reference image data) obtained by performing the adjustment process on the display image data. . The user operates the selection buttons Bb1 and Bb2 while confirming the reference image displayed in the reference image display field Fb, whereby a plurality of pieces of RAW image data included in the plurality of RAW image files stored in the memory card MC are displayed. Desired RAW image data can be selected as image data to be printed.

  The setting screen Wb includes various items for determining processing conditions for printing using RAW image data, as in the setting screen Wa of FIG. However, in the setting screen Wb, instead of the items “brightness correction” and the item “hue correction” included in the setting screen Wa, an item “exposure correction” for selecting the presence / absence and degree of exposure correction, and white The item “white balance correction” for correcting the balance is included.

  In this embodiment, the content of the item “exposure correction” includes “± 0 EV (no correction)”, “+0.5 EV”, “+1.0 EV”, “+1.5 EV”, “+2.0 EV”, “ It can be set to any one of “−0.5 EV”, “−1.0 EV”, “−1.5 EV”, and “−2.0 EV”. The item “exposure correction” is an item for performing exposure correction processing similar to the exposure correction processing in the camera, unlike the item “brightness correction” included in the setting screen Wa of FIG. 5. This exposure correction process is difficult to apply to JPEG image data. With this exposure correction process, it is possible to correct a considerably dark image or a considerably bright image to an image with appropriate brightness. Very useful. In the present embodiment, the content of the item “white balance correction” is any one of the types of light sources such as “daylight”, “cloudy weather”, “shade”, “incandescent light”, “fluorescent light”, etc. Can be set. However, the initial value of the item “white balance correction” is set to a white balance setting value (for example, daylight) described in the header portion of the RAW image file. When the user desires to change the white balance, the light source is changed to another light source type. The content of the item “white balance correction” may be indicated by a color temperature (for example, “3000K”, “4500K”, “5500K”, “6500K”, “7500K”, etc.) instead of the type of the light source. Good.

  On the setting screen Wb, when the user operates the operation unit 270, the RAW image data to be printed is selected and the contents of each item are set. Then, the “print” button BPb is selected by the user.

  In step S124, the processing condition determination unit 240 determines processing conditions for printing using the RAW image data based on the contents of each item acquired by the second setting unit 242b.

  In step S126, the development processing unit 252 performs development processing on the RAW image data according to the processing conditions determined in step S124, and generates developed image data (print image data). Specifically, in step S126, as will be described later, optical black correction processing, white balance correction processing, exposure correction processing, pixel interpolation processing, color reproduction processing, RGB-YUV conversion processing, edge processing is performed on RAW image data. A series of processing such as enhancement processing, noise removal processing, gradation correction processing, and JPEG processing is performed. The white balance correction process is a process of multiplying R data and B data of R (red), G (green), and B (blue) data by coefficients Ar and Ab. The pixel interpolation process is a process for predicting and interpolating color information that is deficient due to the Bayer array of color filters arranged on the image sensor. The color reproduction process is a process for correctly reproducing the color of an image by 3 × 3 matrix calculation. The RGB-YUV conversion process is a color space conversion process for performing JPEG processing. The edge emphasis process is a process for correcting and clarifying a portion where an outline in an image is blurred due to the influence of an optical low-pass filter installed in the camera. The noise removal process is a process for removing a noise component present in an image and generating a clear image. The tone correction process is a process for correcting the tone reproduction characteristics so as to match the tone characteristics of a device (printer) that prints an image.

  When the item “exposure correction” in FIG. 6 is set to “+1.0 EV”, after white balance correction processing, exposure is performed by multiplying each R, G, B data by a coefficient corresponding to +1.0 EV. Correction processing is performed. Since “+1.0 EV” indicates a process of increasing the exposure by one step, a process of doubling each R, G, B data is executed. In the case of “−0.5 EV”, 1 / √2 (= 0.707) is multiplied as a coefficient. When the type of light source is specified in the item “white balance setting” in FIG. 6, the type of light source such as “daylight”, “cloudy weather”, “sunlight”, “incandescent light”, “fluorescent light”, etc. Accordingly, white balance correction processing is performed by multiplying each of the R, G, and B data by a preset coefficient.

  In step S132, the developed image processing unit 254 generates print data. Specifically, when printing using JPEG image data is executed, the developed image processing unit 254 performs processing on the JPEG image data according to the processing conditions determined in step S114, and prints. Generate data. On the other hand, when printing using RAW image data is executed, the developed image processing unit 254 performs the developed image data (printed) subjected to the development processing in step S126 according to the processing conditions determined in step S124. Process image data) to generate print data.

  In step S134, the print execution unit 280 acquires print data from the developed image processing unit 254, and prints an image on a print sheet.

  FIG. 7 is a flowchart showing an example of the procedure of the developing process executed in step S126 of FIG.

  In step S202, the development processing unit 252 executes an optical black correction process. This process is a process for correcting the characteristics of the image sensor of the camera, that is, the characteristic that the detected value does not become zero when the intensity of incident light is zero. In this process, the offset value is subtracted from the gradation value of each pixel included in the RAW image data.

  Note that the processing in step S202 is performed according to, for example, the manufacturer name and model name described in the header portion in the RAW image file. Specifically, the processing condition determination unit 240 analyzes the header part in the RAW image file and acquires the manufacturer name and model name. The processing condition determination unit 240 includes a table (not shown) in which a plurality of combinations of manufacturer name, model name, and processing condition are registered. The processing condition determination unit 240 selects a processing condition by referring to the table from the acquired manufacturer name and model name. Then, the development processing unit 252 executes the process of step S202 using the selected processing condition. In addition, when the processing condition is described in the header part, the processing condition may be used.

  In step S204, the development processing unit 252 executes white balance correction processing for correcting white balance (color temperature). In this process, the gradation value of each pixel is multiplied by a coefficient corresponding to the target white balance for each R, G, B data constituting the RAW image data subjected to the process of step S202. More specifically, in this process, coefficients R and B of the R (red), G (green), and B (blue) data are multiplied by coefficients Ar and Ab.

  The process of step S204 is executed according to the content of the item “white balance correction” on the RAW image print setting screen Wb (FIG. 6). As described above, the content of the item is the same as the white balance setting value described in the header portion of the RAW image file when the initial value has not been changed. When the content of the item “white balance correction” is selected by the user on the setting screen of FIG. 6, selection of “daylight”, “cloudy weather”, “sunlight”, “incandescent light”, “fluorescent light”, etc. In accordance with the type of the light source, the R, G, B data is multiplied by a preset coefficient.

  In step S206, the development processing unit 252 executes exposure correction processing for correcting exposure. In this process, the gradation value of each pixel included in the image data subjected to the process of step S204 is multiplied by a coefficient corresponding to the exposure correction amount.

  Note that the processing in step S206 is executed according to the content of the item “exposure correction” on the RAW image print setting screen Wb (FIG. 6). When the item “exposure correction” is set to other than “± 0 EV (no correction)”, for example, set to “+1.0 EV”, after the white balance correction processing, R, G, B data are processed. Then, a process of multiplying by a coefficient corresponding to +1.0 EV is performed. As described above, “+1.0 EV” indicates a process of increasing the exposure by one step, and thus a process of doubling R, G, B data is executed. In the case of “−0.5 EV”, 1 / √2 (= 0.707) is multiplied as a coefficient. However, when the content of the item “exposure correction” is set to “± 0 EV (no correction)”, the process of step S206 is omitted.

  In step S208, the development processing unit 252 executes pixel interpolation processing (that is, demosaic processing). This pixel interpolation process is a process for interpolating pixels that are missing due to the arrangement of a plurality of sensor elements inside the image sensor of the camera. In an image sensor using RGB primary color filters, each pixel is one of RGB due to the Bayer array of color filters arranged on the sensor. When a certain pixel is an R pixel, G and B image information at the same position is insufficient. When a certain pixel is a G pixel, R and B image information at the same position is insufficient. The pixel interpolation process is a process for obtaining this insufficient color information by predictive interpolation from the color information of surrounding pixels. In this process, the gradation value of the pixel to be interpolated (the missing color component) is determined for each of the R, G, B data constituting the image data subjected to the process of step S206.

  Note that the processing in step S208 may be executed using processing conditions selected in accordance with the manufacturer name and model name described in the header part of the RAW image file, for example, as in step S202. The processing conditions described in the header part may be used.

  In step S210, the development processing unit 252 executes a color reproduction process. Since the RGB spectral characteristics of the image sensor are different from the spectral characteristics of the human eye, correct color reproduction cannot be achieved even if the color outputs of the image sensor are combined. For this reason, it is this color reproduction process that corrects the color to match the characteristics of human visibility. This process is performed by a 3 × 3 matrix operation to correctly reproduce the color of the image.

  In step S212, the development processing unit 252 executes gradation correction processing (gamma correction processing) for correcting gradation characteristics. By performing this process, the linear gradation characteristic of the image data before the process is corrected to a gradation reproduction characteristic that matches the output tone characteristic of the printer 200.

  The development processing unit 252 executes edge enhancement processing and noise removal processing together with steps S202 to S212 shown in FIG. The edge emphasis process is a process for correcting and clarifying a portion where an outline in an image is blurred due to the influence of an optical low-pass filter installed in the camera. The noise removal process is a process for removing a noise component present in an image and generating a clear image. The development processing unit 252 finally generates developed image data (printing image data) in JPEG format. As described above, in this embodiment, developed image data that is JPEG-compressed is generated, but instead, developed image data that is not JPEG-compressed may be generated.

C. Exposure compensation processing:
By the way, when the item “exposure correction” included in the RAW image print setting screen Wb (FIG. 6) is set to a significant value (that is, other than “no correction”), exposure correction processing is performed on the RAW image data. Executed. The exposure correction process is executed by the development processing unit 252 in step S126 of FIG. 3 (more specifically, step S206 of FIG. 7). On the other hand, when the item “brightness correction” included in the JPEG image print screen Wa is set to a significant value (that is, other than “no correction”), the brightness correction process is executed on the JPEG image data. . The brightness correction process is executed by the developed image processing unit 254 in step S132 of FIG.

  The exposure correction process and the brightness correction process are common in that the brightness of an image to be printed (printed image) is changed. However, as will be described below, the exposure correction process and the brightness correction process are completely different processes.

  FIG. 8 is an explanatory diagram showing the contents of the exposure correction process and the contents of the brightness correction process. In FIG. 8, five graphs GAa, GAb, GAc, GBa, and GBb are shown, and the five graphs show the gradation characteristics of five image data. The horizontal axis of each graph indicates the brightness of the subject, and the vertical axis indicates the output brightness of each image data, that is, the brightness (gradation value) of the subject expressed by each image data. The three graphs GAa, GAb, GAc drawn on the left side of FIG. 8 show the contents of the exposure correction process, and the two graphs GBa, GBb drawn on the right side of FIG. 8 show the contents of the brightness correction process. Is shown.

  The graph GAa shows the tone characteristics of the RAW image data. As shown in the graph GAa, in the RAW image data, the brightness (tone value) of the image data changes linearly with respect to the brightness of the subject. This is because RAW image data is generated by analog-digital conversion of the output of the image sensor as it is inside the camera.

  The graph GAc shows the gradation characteristics of the developed image data (print image data) obtained after the development process including the exposure correction process. As shown in the graph GAc, in this image data, the output brightness (tone value) changes nonlinearly with respect to the brightness of the subject. This is because tone correction processing (step S212 in FIG. 7) is executed in the development processing in the printer 200. The broken line shown in the graph GAc indicates the gradation characteristics of the developed image data (printing image data) when the exposure correction process is omitted (when no exposure correction is performed).

  A graph GAb shows the gradation characteristics of the intermediate image data obtained in the process of performing development processing on the RAW image data. More specifically, the graph GAb shows the gradation characteristics of the intermediate image data obtained after the exposure correction process of “+1.0 EV” (step S206 in FIG. 7). As shown in the graph GAb, in this image data, the output brightness (tone value) still varies linearly with respect to the brightness of the subject. The broken line shown in the graph GAb indicates the gradation characteristics of the intermediate image data when the exposure correction process is omitted. As illustrated, the slope of the broken line shown in the graph GAb is twice the slope of the solid line shown in the graph GAb. The exposure correction process of “+1.0 EV” is a process of multiplying by 2 in this way.

  A graph GBa shows the gradation characteristics of JPEG image data. As shown in the graph GBa, in the JPEG image data, the output brightness (tone value) changes nonlinearly with respect to the brightness of the subject. This is because tone correction processing (gamma correction processing) similar to step S212 in FIG. 7 is executed in the JPEG image generation processing (development processing) in the camera.

  A graph GBb shows the gradation characteristics of the JPEG image data obtained after the brightness correction process. As shown in the graph GBb, in this image data, the output brightness (tone value) changes nonlinearly with respect to the brightness of the subject. The broken line shown in the graph GBb shows the same gradation characteristic as that of the graph GBa. The characteristic of the solid line is corrected with respect to the characteristic of the broken line so that the output brightness becomes brighter in the middle of the brightness of the subject.

As can be seen by comparing the two graphs GAc and GBb, the gradation characteristics of the developed image data (printing image data) obtained after the exposure correction and the gradation characteristics of the JPEG image data obtained after the brightness correction processing Is completely different. In the exposure correction process, as shown in the graph GAb, correction is performed by multiplying the gradation value of each pixel of the image data having linear gradation characteristics by a coefficient. In the brightness correction process, the graph GBb is corrected. This is because correction is usually performed to raise the gradation value of each pixel of JPEG image data having nonlinear gradation characteristics to a power. That is, in the brightness correction process, normally, the process of making the middle part of the brightness of the image brighter is performed, and the characteristic of the solid line of the graph GBb is a process of raising the power of Y = X ^{1 / a to} the characteristic of the graph GBa. Is required. For this reason, when the exposure correction process is executed, the same effect as when the exposure is corrected at the time of shooting is obtained. However, when the brightness correction process is executed, the same effect as when the exposure is corrected at the time of shooting is obtained. There is no effect.

  JPEG image data has non-linear gradation characteristics, and the gradation of each pixel is represented by 8 bits in JPEG image data. For this reason, when the brightness correction process is executed so that the image quality does not deteriorate, the brightness correction is limited to +0.5 to −0.5 EV. In other words, it is only possible to correct a failure photo that is slightly insufficient in brightness or a failure photo that is slightly excessive in brightness to a photo of normal brightness. When brightness correction exceeding this range is executed, a gradation jump called a tone jump occurs in a certain gradation range of 8-bit JPEG image data, and the gradation does not change smoothly. It changes unnaturally, and as a result, a beautiful image cannot be obtained. On the other hand, the RAW image data has linear gradation characteristics, and in the RAW image data, the gradation of each pixel is expressed by, for example, 12 bits. In particular, in this embodiment, the development processing unit 252 performs development processing by increasing the gradation of each pixel of the RAW image data from 12 bits to 16 bits. For this reason, in this embodiment, exposure correction of +2.0 to −2.0 EV can be performed with almost no deterioration in image quality.

  As described above, in this embodiment, the RAW image print setting screen Wb (FIG. 6) includes the item “exposure correction” that is not included in the JPEG image print setting screen Wa (FIG. 5). When printing is performed using RAW image data, development processing including exposure correction processing corresponding to the item “exposure correction” is executed, in other words, execution is not possible when printing is performed using JPEG image data. It is possible to easily generate print data from RAW image data by executing development processing including exposure correction processing (that is, exposure correction processing substantially equivalent to that performed in the camera at the photographing stage).

  Although the difference between the item “exposure correction” (FIG. 6) and the item “brightness correction” (FIG. 5) has been described in FIG. 8, the item “white balance correction” (FIG. 6) and the item “color tone correction” are described. The same applies to the difference from FIG. That is, when the type of light source is set in the item “white balance correction”, the gradation value of each pixel corresponds to the target white balance for each RGB data constituting the RAW image data having linear gradation characteristics. Multiply by a factor. On the other hand, when the item “color tone setting” is changed, different arithmetic processing (for example, power) is applied to the gradation value of each pixel for each RGB component of JPEG image data having nonlinear gradation characteristics.

  In this embodiment, the JPEG image print image Wa (FIG. 5) includes an item “brightness correction” and an item “color tone correction”, but these items can be omitted.

  In this embodiment, the item name corresponding to the exposure correction process is “exposure correction”, but other names (for example, “brightness correction” and “EV correction”) may be used instead. . Similarly, in the above-described embodiment, the item name corresponding to the white balance correction process is “white balance correction”, but another name (for example, “hue correction”) may be used instead.

  In particular, in this embodiment, the reference image is displayed in the reference image display field Fb in the RAW image print setting screen Wb (FIG. 6). In other words, the subject represented in the RAW image data to be printed can be quickly grasped before the time-consuming development processing is executed, in other words, without waiting for the completion of the development processing. That is, it is not necessary to wait for a series of development processes that require a very long time to be performed on the RAW image data to generate display image data. As a result, the user can select RAW image data to be printed very quickly.

D. Adjustment of display image data:
As described above, in this embodiment, the reference image displayed in the reference image display field Fa in the RAW image print setting screen Wb (FIG. 6) is created using the display image data included in the RAW image file. ing.

  The gradation reproducibility (brightness of each part of the image) of the reference image displayed on the display panel 260 and the gradation reproducibility (brightness of each part of the image) of the image (printed image) printed by the printer 200 are: It is preferable for the user's needs to select and print an image with appropriate brightness from a plurality of images, so that it looks almost the same by the user, in other words, is recognized by the user to be almost the same. .

However, in practice, it is difficult to make the impression of the brightness of the reference image and the brightness of the printed image the same. The first cause of this problem is that the characteristics of each device are different (the display image is displayed by a light-emitting display panel, and the printed material is a reflective display material printed by a printer). However, the difference in the characteristics of each device can be eliminated by color matching processing. The second cause of the above problem is the gradation characteristics of the display image data included in the RAW image file and the developed image data (print image data) obtained through the gradation correction processing in step S212. The tone characteristics are different. The difference in gradation characteristics is that the display image data is image data obtained by performing a development process (specifically, a gradation correction process) recommended by the camera manufacturer. This is because the developed image data (printing image data) obtained from the RAW image data is image data obtained by performing a development process (specifically, gradation correction process) recommended by the printer manufacturer. . As described above, since the gradation characteristics are different, the brightness characteristics of the display image and the printed matter can be recognized differently by the user even if the appearance of the display image and the printed matter is made equal by using the color matching technique.

  If an image displayed on the display panel 260 is created using developed image data (printing image data) generated by the printer 200, the brightness of the reference image and the brightness of the printed image are set. It is possible to make the user recognize almost the same. However, it takes time to generate image data for printing, in other words, development processing of RAW image data. For this reason, in order to satisfy the user's desire to view images quickly, in the present embodiment, when printing using RAW image data is executed, the display image data is displayed before the development processing is executed. Is used to display a reference image on the display panel 260. However, in this case, as described above, there may arise a problem that the brightness of the reference image and the brightness of the printed image can be recognized differently by the user. In view of this, the present embodiment aims to solve this problem and respond to the user's needs to select an image with appropriate brightness from a plurality of images and print the desired image. There is also a need to print an image with an appropriate exposure correction for an image, but to determine which value should be set for the appropriate exposure correction while looking at the display panel instead of the print result. The purpose is to respond to.

  FIG. 9 is an explanatory diagram showing the gradation characteristic P of the printing image data and the gradation characteristic D of the display image data. Here, a case where RAW image data of a certain camera manufacturer is printed by the printer 200 of this embodiment will be described. The gradation characteristic P (dotted line in FIG. 9) of the image data for printing means the characteristic of the development processing (specifically gradation correction processing) by the development processing unit 252. The gradation characteristic D (solid line in FIG. 9) of the display image data means the characteristic of development processing (specifically gradation correction processing) in the camera. As in FIG. 8, the horizontal axis in FIG. 9 represents the brightness of the subject, in other words, RAW image data (more specifically, in the case where the exposure correction process in step S206 in FIG. 7 is not executed, the step in FIG. This means the brightness (gradation value) of the subject expressed by the image data before the gradation correction processing in S212. The vertical axis indicates the output brightness of each image data, that is, the brightness (gradation value) of the subject expressed by the print image data or the display image data.

  In FIG. 9, the brightness of the subject (the brightness of the RAW image data) indicates the tone value when the maximum tone value that can be taken by the RAW image data (for example, 4095 in 4096 tones) is 1.0. The output brightness (the brightness of each image data) indicates a tone value when the maximum tone value that each image data can take (for example, 255 in 256 tones) is 1.0.

  The gradation characteristic D of the display image data is a gradation correction characteristic created in the camera by each camera maker, and is different from the gradation characteristic P of the printing image data as shown in FIG. From FIG. 9, the output brightness of the image data for printing is large in the range where the brightness of the subject is about 0.05 or less and about 0.7 or more, and the brightness of the subject is about 0.05 to It can be seen that the output brightness of the display image data is smaller in the range of about 0.7.

  When the two tone characteristics P and D are different in this way, as described above, the brightness of the printed image and the brightness of the reference image are recognized differently by the user. Therefore, in the present embodiment, the brightness of the printed image when actually printed is more intuitively devised so that the brightness of the printed image and the brightness of the reference image are recognized almost the same by the user. Provides recognizable convenience.

  Specifically, in the present embodiment, the display image data adjustment unit 244 adjusts the display image data so that the gradation characteristic D of the display image data approaches the gradation characteristic P of the print image data. . The adjustment process is executed when the reference image is displayed in the reference image display field Fb of the RAW image print setting screen Wb (FIG. 6) in step S122 of FIG.

  However, the gradation characteristic D of the display image data depends on the type of the camera that generated the display image data, specifically, the developing process (more specifically, the gradation correction process) of the camera. For this reason, in this embodiment, the processing conditions of the adjustment process are changed according to the type of camera. Specifically, the display image data adjustment unit 244 analyzes the header part in the RAW image file including the display image data, and acquires the manufacturer name and the model name. The display image data adjustment unit 244 includes a table (not shown) in which a plurality of combinations of manufacturer names, model names, and processing conditions are registered. The display image data adjustment unit 244 selects a processing condition from the acquired manufacturer name and model name with reference to the table. Then, the display image data adjustment unit 244 executes the adjustment process using the selected processing condition. In this way, it is possible to appropriately perform the adjustment process according to the gradation characteristics of the display image data that can be different for each type of camera.

  Various methods may be used as the adjustment processing method. Hereinafter, three types of adjustment methods will be described assuming that a RAW image file including display image data is generated by a specific type of camera.

D-1. First adjustment method:
In the first adjustment method, the display image data adjustment unit 244 performs adjustment processing on the display image data based on the following equation (1) to generate adjusted display image data.

  Y = a · X (1)

  Here, X represents the brightness of the display image data, that is, the gradation value before adjustment processing, and is the gradation value when the maximum gradation value that the display image data can take is 1.0. Y indicates the brightness of the adjusted display image data, that is, the gradation value after the adjustment process, and is the gradation value when the maximum gradation value that can be taken by the adjusted display image data is 1.0. a is a positive value and is changed according to the type of camera. In this embodiment, a = 0.95 is set.

  FIG. 10 is an explanatory diagram showing the relationship between the brightness of the display image data and the brightness of the adjusted display image data when the first adjustment method is used. The straight line C1 shown in FIG. 10 is represented by the above formula (1). In FIG. 10, for reference, a straight line with Y = X is indicated by a one-dot chain line. As can be seen from the straight line C1, in the first adjustment method, the brightness of the display image data is reduced in the entire gradation range after the adjustment process. For example, a pixel having a brightness of 0.5 included in the display image data has a brightness of 0.475 (= 0.95 × 0.5) in the adjusted display image data.

  In FIG. 10, the maximum value of the brightness of the display image data shown on the horizontal axis is about 0.9 because the brightness (output brightness) of the display image data shown on the vertical axis in FIG. ) Corresponds to the maximum value of about 0.9.

  FIG. 11 is an explanatory diagram showing the gradation characteristic D1 of the adjusted display image data when the first adjustment method is used. In FIG. 11, the two gradation characteristics P and D shown in FIG. 9 are also shown.

  As can be seen from the gradation characteristic D1 of the image data for adjustment shown in FIG. 11, the gradation characteristic D of the image data for display has a brightness of the subject in the range of about 0.05 to about 0.6 after the adjustment process. It can be said that the gradation characteristic P of the print image data is approaching.

  If the first adjustment method is adopted, the brightness of the reference image and the brightness of the printed image can be recognized almost the same by the user in a halftone that is frequently used. Further, in the first adjustment method, the above-described formula (1) is used, so that the adjustment process can be executed easily and quickly.

D-2. Second adjustment method:
In the second adjustment method, the display image data adjustment unit 244 performs adjustment processing on the display image data based on the following equation (2) to generate adjusted display image data.

Y = b · X ^c (2)

  Here, b and c are positive values, and are changed according to the type of camera. In this embodiment, b = 1.05 and c = 1.2 are set.

FIG. 12 is an explanatory diagram showing the relationship between the brightness of the display image data and the brightness of the adjusted display image data when the second adjustment method is used. A curve C2 shown in FIG. 12 is expressed by the above equation (2). As can be seen from the curve C2, in the second adjustment method, the brightness of the display image data is reduced in the relatively low gradation range and increased in the relatively high gradation range after the adjustment processing. For example, a pixel having a brightness of 0.5 included in the display image data has a brightness of about 0.457 (= 1.05 × (0.5) ^1.2 ) in the adjusted display image data. A pixel having a brightness of 0.9 included in the data has a brightness of about 0.925 (= 1.05 × (0.9) ^1.2 ) in the adjusted display image data.

  FIG. 13 is an explanatory diagram showing the gradation characteristics D2 of the adjusted display image data when the second adjustment method is used. In FIG. 13, the two gradation characteristics P and D shown in FIG. 9 are also shown.

  As can be seen from the gradation characteristic D2 of the image data for adjustment shown in FIG. 13, the gradation characteristic D of the display image data is the image for printing in a wide range where the brightness of the subject is about 0.1 or more after the adjustment processing. It can be said that the gradation characteristic P of the data is very close.

  If the second adjustment method is adopted, the brightness of the reference image and the brightness of the printed image can be recognized almost the same by the user from the halftone to the bright part. Further, in the second adjustment method, the above-described expression (2) is used, so that the adjustment process can be executed easily and quickly. By applying the adjustment process shown in FIG. 12 to the display image data having the gradation characteristic D shown in FIG. 9, the gradation characteristic D2 shown in FIG. 13 is obtained, so that the user can view the image viewed on the display panel. It can be felt that the brightness characteristics of the print and the brightness of the printed matter are almost equal.

D-3. Third adjustment method:
In the third adjustment method, the display image data adjustment unit 244 performs adjustment processing on the display image data by using an LUT (Look Up Table) (not shown) to generate adjusted display image data. .

  FIG. 14 is an explanatory diagram showing the relationship between the brightness of the display image data and the brightness of the adjusted display image data when the third adjustment method is used. The relationship of the curve C3 shown in FIG. 14 is registered in the LUT.

  As can be seen from the curve C3, in the third adjustment method, the brightness of the display image data is increased in the gradation range of about 0.2 or less and about 0.85 or more after the adjustment process, and is about 0.2. It is reduced in a gradation range of about 0.85. The relationship shown in FIG. 14 is set based on the relationship between the two gradation characteristics P and D shown in FIG. That is, in FIG. 9, the output brightness of the display image data is smaller than the output brightness of the print image data when the output brightness of the display image data is in the range of about 0.2 or less and about 0.85 or more. When the output brightness of the image data is in the range of about 0.2 to about 0.85, the output brightness of the display image data is greater than the output brightness of the print image data. The relationship shown in FIG. 14 is set so as to correct the relationship shown in FIG. 9, that is, the gradation characteristic D of the display image data matches the gradation characteristic P of the print image data. Yes.

  FIG. 15 is an explanatory diagram showing the gradation characteristic D3 of the adjusted display image data when the third adjustment method is used. FIG. 15 also shows the two gradation characteristics P and D shown in FIG.

  As can be seen from the gradation characteristic D3 of the image data for adjustment shown in FIG. 15, the gradation characteristic D of the image data for display is the gradation characteristic of the image data for printing in the entire range of the brightness of the subject after the adjustment processing. It is consistent with P.

  If the third adjustment method is adopted, the brightness of the reference image and the brightness of the printed image can be recognized almost the same by the user in all gradations. The user can feel that the characteristics of the brightness of the image viewed on the display panel and the brightness of the printed matter are almost equal.

  As described above, in this embodiment, the gradation characteristic D of the display image data is adjusted so that the gradation characteristic D of the display image data approaches the gradation characteristic P of the printing image data. For this reason, by checking the reference image, the user can quickly grasp the brightness of the printed image without waiting for the completion of the development process before the development process requiring a long time is executed. can do. As a result, it is possible to prevent unnecessary printing. In other words, since the user can instruct the start of printing after selecting an image with the optimum brightness, the user may print an excessively bright failed photo or an excessively dark failed photo. There is no need to perform useless printing.

  In the present embodiment, the above-described color matching process for making the brightness characteristic (gradation characteristic) of the display image and the brightness characteristic (gradation characteristic) of the printed material the same is performed in the display panel 260 of FIG. It is done in.

  In the present specification, adjusting display image data “so that the gradation characteristics of display image data approaches the gradation characteristics of print image data” means the brightness of a subject (the brightness of RAW image data). In at least a part of the range (for example, halftone), the difference between the brightness of the adjusted display image data and the brightness of the printing image data is greater than the difference between the brightness of the display image data and the brightness of the printing image data. This means that the display image data is adjusted to be smaller.

E. Adjustment of display image data according to exposure compensation amount:
By the way, when the content of the item “exposure correction” included in the RAW image print setting screen Wb (FIG. 6) is set to a significant value (that is, other than “no correction”) by the user, It is preferable that an image whose brightness is adjusted in accordance with the exposure correction amount is displayed. Even when the content of the item “exposure correction” on the setting screen Wb is set to a significant value by the user, the brightness of the reference image and the brightness of the printed image are recognized almost the same by the user. Is preferred. This makes it possible for the user to select an optimal exposure correction amount while viewing the image in the reference image display field Fb in FIG. 6, and the convenience for the user is greatly improved. Therefore, in this embodiment, even when the exposure correction amount is set to a significant value, the brightness of the reference image and the brightness of the printed image that has been subjected to the exposure correction processing are recognized by the user to be almost the same. It is devised as follows.

  When the exposure correction amount is set to a significant value, the development processing unit 252 executes exposure correction processing in step S206 (FIG. 7). As described above, in the exposure correction process, the gradation value of each pixel included in the RAW image data is multiplied by a coefficient corresponding to the exposure correction amount.

Table 1 below shows the relationship between the exposure correction amount and the coefficient multiplied by the RAW image data. As can be seen from Table 1, the exposure correction amount is “nEV” (n is +2.0, +1.5, +1.0, +0.5, ± 0, −0.5, −1.0, −1. When set to any one of 5, 2.0, the coefficient is set to 2 ⁿ . For example, when the exposure correction amount is set to “+2.0 EV”, the gradation value of each pixel included in the RAW image data is multiplied by 4 (= 2 + ^2.0 ).

  When the exposure correction process corresponding to the exposure correction amount is performed based on Table 1, developed image data (print image data) corresponding to the exposure correction amount is generated (see FIG. 7). The developed image data (printing image data) is generated by the series of processes shown in FIG. In the example of FIG. 8 described above, the graph GAa (FIG. 8) is changed to the characteristic of the solid line of the graph GAb by the exposure correction processing in step S206, and the solid line of the graph GAc by the gradation correction processing (gamma correction processing) in step S212. The characteristics are changed.

  FIG. 16 is an explanatory diagram showing the gradation characteristics P, Pha to Phd, and Pla to Pld of the printing image data according to the exposure correction amount. The gradation characteristic P in FIG. 16 is the same as the gradation characteristic P in FIG. 9 and is obtained when the exposure correction amount is set to “± 0 EV (no correction)”. The gradation characteristics Pha, Phb, Phc, and Phd are obtained when the exposure correction amounts are set to “+0.5 EV”, “+1.0 EV”, “+1.5 EV”, and “+2.0 EV”, respectively. . The gradation characteristics Pla, Plb, Plc, and Pld are set to exposure correction amounts of “−0.5 EV”, “−1.0 EV”, “−1.5 EV”, and “−2.0 EV”, respectively. Obtained if you do.

  In step S122 of FIG. 3, the display image data adjustment unit 244 converts the display image data according to the exposure correction amount set in the item “exposure correction” in the RAW image print setting screen Wb (FIG. 6). adjust. Specifically, the display image data has the gradation characteristics D of the display image data to the gradation characteristics P, Pha to Phd, and Pla to Pld of the printing image data corresponding to the exposure correction amount shown in FIG. It is adjusted according to the exposure correction amount so as to approach. Even when the display image data is adjusted according to the exposure correction amount, as described above, the processing conditions of the adjustment process are changed according to the type of the camera that generated the display image data. In this way, it is possible to appropriately perform the adjustment process according to the exposure correction amount in accordance with the gradation characteristics of the display image data that may be different for each type of camera.

  In the following, assuming that the RAW image file including the display image data is generated by the above-mentioned specific type of camera, the adjustment process according to the exposure correction amount using the above-described three types of adjustment methods. The case where is executed will be described.

E-1. First adjustment method:
In the first adjustment method, the display image data adjustment unit 244 performs adjustment processing according to the exposure correction amount on the display image data based on the following equation (3), and the adjusted display image data is converted into the adjusted display image data. Generate.

  Y = A · X (3)

  Here, A is a positive value set according to the exposure correction amount, and is changed according to the camera model.

  Table 2 below shows the relationship between the exposure correction amount and the value of A in the above equation (3). For example, when the exposure correction amount is set to “+2.0 EV”, “A = 2.2” is set. When the exposure correction amount is set to “± 0 EV (no correction)”, “A = 0.95” is set as described above with respect to the equation (1).

  FIG. 17 is an explanatory diagram illustrating the relationship between the brightness of the display image data and the brightness of the adjusted display image data according to the exposure correction amount when the first adjustment method is used. Each straight line C1, C1ha to C1hd, and C1la to C1ld shown in FIG. 17 is expressed by the above equation (3). A straight line C1 in FIG. 17 is the same as the straight line C1 in FIG. Note that the end of the code of each straight line (“ha” or the like) is attached according to the exposure correction amount, as in FIG. 16, and each straight line C1ha to C1hd and C1la to C1ld has the exposure correction amount “ +0.5 EV, “+1.0 EV”, “+1.5 EV”, “+2.0 EV”, “−0.5 EV”, “−1.0 EV”, “−1.5 EV”, “−2.0 EV” It corresponds to.

  FIG. 18 is an explanatory diagram showing the gradation characteristics D1, D1ha to D1hd, D1la to D1ld of the adjusted display image data according to the exposure correction amount when the first adjustment method is used. The gradation characteristic D1 in FIG. 18 is the same as the gradation characteristic D1 in FIG. Note that the end of the sign (“ha” etc.) of each gradation characteristic is given according to the exposure correction amount, as in FIG. 16, and each gradation characteristic D1ha to D1hd, D1la to D1ld is exposure correction. The quantities “+0.5 EV”, “+1.0 EV”, “+1.5 EV”, “+2.0 EV”, “−0.5 EV”, “−1.0 EV”, “−1.5 EV”, “−2. 0EV ". Further, FIG. 18 further shows the gradation characteristics D of the display image data shown in FIG. 9 and the three gradation characteristics P, Phd, and Pld of the printing image data shown in FIG. .

  As can be seen from the gradation characteristics D1, D1ha to D1hd and D1la to D1ld of the adjusted display image data shown in FIG. 18, if the first adjustment method is adopted, the gradation characteristics D of the display image data are adjusted. After the processing, the gradation characteristics P, Pha to Phd, and Pla to Pld of the printing image data according to the exposure correction amount can be brought close to. Further, in the first adjustment method, the above-described expression (3) is used, so that the adjustment process according to the exposure correction amount can be executed easily and quickly.

E-2. Second adjustment method:
In the second adjustment method, the display image data adjustment unit 244 performs adjustment processing on the display image data in accordance with the exposure correction amount based on the following expression (4), and the adjusted display image data is displayed. Generate.

Y = B · X ^C (4)

  Here, B and C are positive values set according to the exposure correction amount, and are changed according to the camera model.

  Table 3 below shows the relationship between the exposure correction amount and B and C in the above equation (4). For example, when the exposure correction amount is set to “+2.0 EV”, “B = 1.3” and “C = 0.6” are set. Further, when the exposure correction amount is set to “± 0 EV (no correction)”, “B = 1.05” and “C = 1.2” are set as described above with respect to the equation (2). The

  FIG. 19 is an explanatory diagram showing the relationship between the brightness of the display image data and the brightness of the adjusted display image data according to the exposure correction amount when the second adjustment method is used. Each curve C2, C2ha-C2hd, C2la-C2ld shown in FIG. 19 is expressed by the above-mentioned formula (4). A curve C2 in FIG. 19 is the same as the curve C2 in FIG. Note that the end of the sign of each curve (“ha” or the like) is given according to the exposure correction amount, as in FIG. 16, and each curve C2ha to C2hd and C2la to C2ld is the exposure correction amount “ +0.5 EV, “+1.0 EV”, “+1.5 EV”, “+2.0 EV”, “−0.5 EV”, “−1.0 EV”, “−1.5 EV”, “−2.0 EV” It corresponds to.

  FIG. 20 is an explanatory diagram showing the gradation characteristics D2, D2ha to D2hd, D2la to D2ld of the adjusted display image data in accordance with the exposure correction amount when the second adjustment method is used. The gradation characteristic D2 in FIG. 20 is the same as the gradation characteristic D2 in FIG. Note that the end of the sign of each gradation characteristic (“ha” or the like) is added according to the exposure correction amount, as in FIG. 20 further shows the gradation characteristics D of the display image data shown in FIG. 9, and the three gradation characteristics P, Phd, and Pld of the printing image data shown in FIG. .

  As can be seen from the gradation characteristics D1, D1ha to D1hd and D1la to D1ld of the adjusted display image data shown in FIG. 20, if the second adjustment method is adopted, the gradation characteristics D of the display image data are adjusted. After the processing, the gradation characteristics P, Pha to Phd, and Pla to Pld of the printing image data according to the exposure correction amount can be made considerably close. Further, in the second adjustment method, the above-described expression (4) is used, so that the adjustment process according to the exposure correction amount can be executed easily and quickly.

E-3. Third adjustment method:
In the third adjustment method, the display image data adjustment unit 244 uses an unillustrated LUT (Look Up Table) to perform adjustment processing on the display image data in accordance with the exposure correction amount, and has been adjusted. Display image data is generated.

  FIG. 21 is an explanatory diagram showing the relationship between the brightness of the display image data and the brightness of the adjusted display image data according to the exposure correction amount when the third adjustment method is used. The relationship between the curves C3, C3ha to C3hd, and C3la to C3ld shown in FIG. 21 is registered in the LUT. A curve C3 in FIG. 21 is the same as the curve C3 in FIG. Note that the end of the sign of each curve (“ha” or the like) is attached according to the exposure correction amount, as in FIG. 16, and each curve C3ha to C3hd, C3la to C3ld is the exposure correction amount “ +0.5 EV, “+1.0 EV”, “+1.5 EV”, “+2.0 EV”, “−0.5 EV”, “−1.0 EV”, “−1.5 EV”, “−2.0 EV” It corresponds to. 21 is related to the gradation characteristics D of the display image data shown in FIG. 9 and the print images corresponding to the exposure correction amounts shown in FIG. 16, as described in FIG. It is set based on the relationship between the data gradation characteristics P, Pha to Phd, and Pla to Pld.

  If the third adjustment method is used, although not shown, the gradation characteristics D of the display image data are adjusted to the gradation characteristics P, Pha of the printing image data corresponding to the exposure correction amount after the adjustment processing. Phd, Pla to Pld can be matched. In other words, if the third adjustment method is adopted, the brightness of the reference image and the brightness of the printed image can be recognized almost the same by the user for all exposure correction amounts.

  As described above, in this embodiment, the gradation characteristics of the display image data are adjusted according to the exposure correction amount. Therefore, the brightness of the reference image can be changed according to the exposure correction amount before the development process including the exposure correction process is executed. As a result, the user can select the user's favorite exposure correction amount while confirming the reference image on the display panel, and can set the exposure correction amount without actually executing the development processing including the exposure correction processing. It can be done easily. At this time, the brightness of the reference image is immediately changed every time the operation button is operated to set the exposure correction amount to “+1.0 EV”, “+1.5 EV”, “+0.5 EV”, or the like. The user can easily change the exposure correction amount setting without waiting time, and if printing is performed with the exposure correction amount selected on the setting screen Wb, a printed image having the desired brightness can be obtained. It can be obtained and the convenience for the user is greatly improved.

  In particular, in this embodiment, the display image data is adjusted in accordance with the exposure correction amount so that the gradation characteristic of the display image data approaches the gradation characteristic of the printing image data in accordance with the exposure correction amount. The For this reason, the user confirms the reference image before executing the development process that takes a long time, in other words, without waiting for the completion of the development process, the printed image corresponding to the exposure correction amount. The brightness of the can be quickly grasped. As a result, it is possible to prevent unnecessary printing.

  In this specification, the display image data is adjusted in accordance with the exposure correction amount “so that the gradation characteristic of the display image data approaches the gradation characteristic of the print image data in accordance with the exposure correction amount”. Then, in at least a partial range (for example, halftone) of the brightness of the subject (the brightness of the RAW image data), the brightness of the adjusted display image data and the brightness of the print image data corresponding to the exposure correction amount This means that the display image data is adjusted according to the exposure correction amount so that the difference is smaller than the difference between the brightness of the display image data and the lightness of the printing image data according to the exposure correction amount. To do.

  In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it can be implemented in a various aspect, For example, the following deformation | transformation is also possible.

(1) Although the print setting selection screen W (FIG. 4) is displayed in the above embodiment, the selection screen W can be omitted. In this case, for example, the JPEG image print setting screen Wa and the RAW image print setting screen Wb may be displayed by selecting the first button and the second button included in the operation unit 270, respectively.

(2) In the above embodiment, the two setting screens Wa and Wb (FIGS. 5 and 6) include the reference image display fields Fa and Fb, respectively, but the reference image display fields Fa and Fb can be omitted. . In this case, the display image data adjustment unit 244 is also omitted.

(3) In the above embodiment, the reference image display field Fb is provided in a part of the area in the RAW image print setting screen Wb (FIG. 6). Instead, the entire setting screen Wb is referred to. An image display field Fb may be provided. In this case, a selection button, a plurality of items, and the like may be superimposed and displayed on the reference image display field Fb.

(4) In the above embodiment, the RAW image data and the display image data are included in the RAW image file. Instead, the RAW image data and the display image data are included in different files. In addition, the RAW image data and the display image data may be associated with each other.

  In the above embodiment, the RAW image file includes the RAW image data and the display image data. However, even when the display image data is not included, the reference image can be displayed in the reference image display field Fb. is there. For example, when JPEG image data recorded together with RAW image data is included in the RAW image file, the reference image is displayed in the reference image display field Fb by performing reduction processing on the JPEG image data. Just do. If the JPEG image data is not included in the RAW image file, the reference image may be displayed in the reference image display field Fb by performing high-speed development processing on the RAW image data. In high-speed development processing, the number of pixels of RAW image data and / or the number of bits of each pixel is reduced.

(5) In the above embodiment, when the exposure is not corrected (that is, set to “± 0 EV (no correction)”) in step S122 of FIG. 3, the adjustment processing for the display image data is executed. However, instead of this, the adjustment process may be omitted if the exposure is not corrected. Also in this case, when the exposure is corrected, the brightness of the reference image displayed in the reference image display field Fb can be changed according to the exposure correction amount.

(6) In the above embodiment, the exposure correction range is set to +0.2 EV to −0.2 EV, but instead, it may be set to a wider range or a narrower range. In the above embodiment, the exposure correction amount can be set every 0.5 EV. Instead, it can be set every 1.0 EV, every 0.25 EV, every 0.1 EV, and the like. May be.

(7) In the above embodiment, three types of adjustment methods for adjusting the gradation characteristics of the display image data have been described, but other methods may be used instead. For example, a method in which the first adjustment method and the second adjustment method are combined may be used. In this case, for example, the first adjustment method and the second adjustment method may be properly used according to the brightness (gradation value) of the display image data.

(8) In the above embodiment, the type of camera that has generated the RAW image file including the RAW image data and the display image data is specified by checking the manufacturer name and model name described in the header portion of the RAW image file. However, instead of this, the user may specify the camera manufacturer name and model name.

(9) In the above embodiment, for convenience of explanation, the case where printing is performed using JPEG image data and RAW image data has been described, but in addition to this, developed images of other formats such as the BMP format are used. Printing may be performed using the data.

(10) In the above embodiment, the case where the present invention is applied to the printer 200 has been described. However, the present invention can be applied to a personal computer, an image viewer device, a camera, or the like instead. In general, the present invention is applicable to a print control apparatus that uses a display unit and a print execution unit.

(11) In the above embodiment, a part of the configuration realized by hardware may be replaced by software, and conversely, a part of the configuration realized by software may be replaced by hardware.

It is explanatory drawing which shows the printer 200 in an Example. It is explanatory drawing which shows typically the structure of the RAW image file containing RAW image data. It is a flowchart which shows the procedure of a printing process. 5 is an explanatory diagram showing a print setting selection screen W. FIG. It is explanatory drawing which shows the JPEG image print setting screen Wa. It is explanatory drawing which shows the RAW image print setting screen Wb. 4 is a flowchart illustrating an example of a procedure of development processing executed in step S126 of FIG. 3. It is explanatory drawing which shows the content of the exposure correction process, and the content of the brightness correction process. It is explanatory drawing which shows the gradation characteristic P of the image data for printing, and the gradation characteristic D of the image data for display. It is explanatory drawing which shows the relationship between the brightness of the display image data at the time of using the 1st adjustment method, and the brightness of adjusted image data for display. It is explanatory drawing which shows the gradation characteristic D1 of the adjusted image data for a display at the time of using the 1st adjustment method. It is explanatory drawing which shows the relationship between the brightness of the display image data at the time of using the 2nd adjustment method, and the brightness of adjusted image data for adjustment. It is explanatory drawing which shows the gradation characteristic D2 of the adjusted image data for a display at the time of using the 2nd adjustment method. It is explanatory drawing which shows the relationship between the brightness of the display image data at the time of using a 3rd adjustment method, and the brightness of the adjusted display image data. It is explanatory drawing which shows the gradation characteristic D3 of the adjusted image data for a display at the time of using a 3rd adjustment method. It is explanatory drawing which shows the gradation characteristics P, Pha-Phd, Pla-Pld of the image data for printing according to the exposure correction amount. It is explanatory drawing which shows the relationship between the brightness of the image data for a display in the case of using the 1st adjustment method, and the brightness of the image data for display adjusted according to the exposure correction amount. It is explanatory drawing which shows the gradation characteristics D1, D1ha-D1hd, D1la-D1ld of the adjusted display image data according to the exposure correction amount when the first adjustment method is used. It is explanatory drawing which shows the relationship between the brightness of the display image data at the time of using the 2nd adjustment method, and the brightness of the adjusted display image data according to the exposure correction amount. It is explanatory drawing which shows the gradation characteristics D2, D2ha-D2hd, D2la-D2ld of the image data for display adjusted according to the exposure correction amount at the time of using the 2nd adjustment method. It is explanatory drawing which shows the relationship between the brightness of the image data for a display in the case of using a 3rd adjustment method, and the brightness of the image data for display adjusted according to the exposure correction amount.

Explanation of symbols

200 ... Printer 210 ... CPU
DESCRIPTION OF SYMBOLS 220 ... Internal storage device 230 ... Print control part 240 ... Processing condition determination part 242a ... 1st setting part 242b ... 2nd setting part 244 ... Image data adjustment part for display 250 ... Print data generation part 252 ... Image processing part 254 Developed image processing unit 260 Display panel 270 Operation unit 280 Print execution unit 290 Interface (I / F) unit MC Memory card

Claims (10)

A print control device that uses a display unit and a print execution unit,
A print data generation unit that executes development processing on undeveloped image data and generates print data supplied to the print execution unit, wherein the development processing is executed in accordance with a set exposure correction amount. The print data generation unit including an exposure correction process;
Before the development processing is executed, the gradation characteristics of the developed display image data representing the subject represented in the undeveloped image data are adjusted according to the exposure correction amount. A display image data adjusting unit for causing the display unit to display an image represented by the display image data;
A printing control apparatus comprising: The print control apparatus according to claim 1,
The print data generation unit executes the development processing to generate developed print image data, generates the print data using the print image data,
The display image data adjusting unit adjusts the exposure image data according to the exposure correction amount so that the gradation characteristic of the display image data approaches the gradation property of the print image data according to the exposure correction amount. A print controller that performs the adjustment. The print control apparatus according to claim 1 or 2,
The display image data adjustment unit obtains information for specifying a generation device that has generated the display image data, and changes the adjustment processing condition according to the exposure correction amount based on the information. Print control device. The print control apparatus according to claim 1 or 2,
The display image data adjusting unit adjusts the gradation characteristics of the display image data based on Y = A · X.
Here, X is the gradation value of the display image data when the maximum gradation value that the display image data can take is 1, and Y is the maximum gradation that the adjusted display image data can take. The gradation value of the adjusted display image data when the value is 1, and A is a value corresponding to the exposure correction amount. The print control apparatus according to claim 1 or 2,
The display image data adjustment unit adjusts the gradation characteristics of the display image data based on Y = B · X ^C.
Here, X is the gradation value of the display image data when the maximum gradation value that the display image data can take is 1, and Y is the maximum gradation that the adjusted display image data can take. The gradation values of the adjusted display image data when the value is set to 1, and B and C are values according to the exposure correction amount. The print control apparatus according to claim 2,
The display image data adjustment unit uses a table prepared in advance based on the gradation characteristics of the printing image data and the gradation characteristics of the display image data according to the exposure correction amount, A print control apparatus for adjusting gradation characteristics of the display image data. A printer,
The display unit;
The print execution unit;
A printing control apparatus according to any one of claims 1 to 6;
A printer comprising: A print control method using a display unit and a print execution unit,
(A) A step of executing development processing on undeveloped image data and generating print data supplied to the print execution unit, wherein the development processing is executed according to a set exposure correction amount. Including the exposure correction processing,
(B) Before the development processing is executed, the gradation characteristics of the developed display image data representing the subject represented in the undeveloped image data are adjusted according to the exposure correction amount; Displaying the image represented by the adjusted image data for display on the display unit;
A printing control method comprising: A computer program for causing a print control apparatus using a display unit and a print execution unit to execute processing,
A function of executing development processing on undeveloped image data and generating print data supplied to the print execution unit, wherein the development processing is performed according to a set exposure correction amount Said function including processing; and
Before the development processing is executed, the gradation characteristics of the developed display image data representing the subject represented in the undeveloped image data are adjusted according to the exposure correction amount. A function of causing the display unit to display an image represented by the display image data;
Is realized by the print control apparatus.   A computer-readable recording medium on which the computer program according to claim 9 is recorded.

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