JP2019067097A - Image processing device, image processing method, and program - Google Patents

Abstract

To enable display of an image having a high dynamic range, when displaying images output from a plurality of devices in a superimposing manner, without greatly degrading the image quality even if pixel deviation is generated between the superimposed images.SOLUTION: An image processing device in an image forming system of displaying an output image from a first device and an output image from a second device in a superimposing manner on the basis of an inputted image data, thereby forming an image indicated by the inputted image data, includes: dividing means for dividing the inputted image data into a color difference component and a luminance component; first generating means for generating image data for the first device in order to cause the first device to output the output image only on the basis of the luminance component without using the color difference component; and second generating means for generating image data for the second device in order to cause the second device to output the output image only on the basis of the color difference component without using the luminance component.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technology for outputting a high dynamic range image using a plurality of devices.

  In recent years, opportunities for handling high dynamic range images (HDR images) have increased in subjects in the natural world photographed with digital cameras and the like. When viewing such HDR images, it is required to faithfully reproduce human subjective vision by display devices and output devices. At that time, devices such as a projector capable of displaying an image on a large screen, and a large format printer capable of high definition and large format output reproduce the color, gradation, texture, etc. of a real (subject) in a powerful size. As it is possible, the use of these devices is expected.

  On the other hand, the dynamic range and color gamut possessed by these devices are not sufficient to reproduce an HDR image. Therefore, a technology has been proposed that combines and displays an HDR image between a projector and a printer, and reproduces it in a wider color gamut. Patent Document 1 discloses a conversion LUT generated based on spectral distribution characteristics of a projector and spectral reflectance characteristics of a printer when converting an input image into RGB signals for a projector and CMY signals for a printer. The technology used is proposed. In the technology described in Patent Document 1, an image formed by a projector and an image formed by a printer are superimposed on the basis of an image signal converted using the LUT. Thereby, it is possible to reproduce the input image more faithfully while expanding the dynamic range and the color gamut.

Patent 2010-103863 gazette

  However, in the technology described in Patent Document 1, the luminance component is displayed on both the projector and the printer. Therefore, there is a possibility that the displayed image may appear to be blurred if only a shift of several pixels occurs between the superimposed images.

  Therefore, according to the present invention, when displaying images output from a plurality of devices in a superimposed manner, an image with a high dynamic range is displayed without significantly degrading the image quality even when pixel misalignment occurs between the images to be superimposed. It is an object of the present invention to provide an image processing apparatus capable of

  An image processing apparatus according to the present invention forms an image represented by input image data by superimposing and displaying an output image by a first device and an output image by a second device based on input image data. An image processing apparatus in a system, which causes an output image to be output to a first device based on only a luminance component without using division means for dividing input image data into a chrominance component and a luminance component and without using the chrominance component. First generating means for generating image data for the first device, and for the second device for causing the second device to output an output image based only on the color difference component without using the luminance component And second generation means for generating image data of

  According to the present invention, when superimposing and displaying images output from a plurality of devices, an image with a high dynamic range is displayed without significantly degrading the image quality even when pixel misalignment occurs between the superimposed images. be able to.

It is a block diagram showing composition of a system containing an image processing device of a 1st embodiment. It is a flow chart which shows processing of an image processing device of a 1st embodiment. It is a figure which shows a mode that an input image is processed by the image processing apparatus of 1st Embodiment. It is a block diagram which shows the structure of the image processing apparatus of 2nd Embodiment. It is a flow chart which shows processing of an image processing device in a 2nd embodiment. It is a flowchart which shows the process of an image distribution part. It is a figure which shows a mode that an input image is processed by the image processing apparatus of 2nd Embodiment. It is a figure which shows a mode that an input image is processed by the image processing apparatus of 2nd Embodiment. FIG. 1 is a diagram showing a color gamut range of a system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the structure shown in the following embodiment is only an example, and this invention is not necessarily limited to the illustrated structure.

Embodiment 1
<Image processing device>
FIG. 1 is a block diagram showing the configuration of an image forming system including the image processing apparatus 100 according to the first embodiment. As shown in FIG. 1, the image processing apparatus 100 according to the present embodiment includes an image input unit 101, an image division unit 102, a first image generation unit 103, and a second image generation unit 104. Further, as shown in FIG. 1, a printer 110 and a projector 120 are connected to the image processing apparatus 100.

  The image input unit 101 inputs image data (hereinafter sometimes referred to as an image signal). In the present embodiment, the image input unit 101 inputs image data obtained by photographing with a digital camera or the like, for example, image data (RGB image data) having pixel values of respective colors of RGB.

  The image dividing unit 102 performs processing of dividing the input RGB image data into a luminance component and a color difference component. As a method of dividing RGB image data, for example, input image data may be divided into BT. As a method 709, there is a method of converting RGB signals into YCrCb signals, Y as a luminance component, and CrCb as a color difference component. For example, there is a method of converting the input image data as Aces RGB, converting the RGB signal into a Lab signal, setting L as a luminance component and ab as a color difference component.

  The first image generation unit 103 generates image data that can be output by the printer 110 from the luminance component image data obtained by the image division unit 102. The printer 110 outputs (prints) the image data generated by the first image generation unit 103.

  The second image generation unit 104 generates image data that can be output by the projector 120 from the color difference component image data obtained by the image division unit 102. The projector 120 outputs (projects) the image data generated by the second image generation unit 104.

<Process of Embodiment Image Processing Device>
FIG. 2 is a flowchart showing processing of the image processing apparatus 100 according to the first embodiment. FIG. 3 is a view showing how an input image is processed by the image processing apparatus of the first embodiment.

  First, the image input unit 101 inputs image data (step S201). In the present embodiment, as described above, the image input unit 101 inputs RGB image data obtained by imaging with a digital camera or the like. An input image 301 illustrated in FIG. 3 is an example of an image (input image) indicated by RGB image data input by the image input unit 101.

  Next, the image dividing unit 102 divides the image data (referred to as input image data) input by the image input unit 101 into a luminance component and a color difference component (step S202). In the present embodiment, the image dividing unit 102 converts an RGB signal into a YCrCb signal, and divides Y into a luminance component, and divides CrCb into a color difference component. Then, the image dividing unit 102 generates luminance component image data including the luminance component Y as image data (image data for the printer 110) to be output to the printer 110. Further, the image dividing unit 102 generates color difference component image data composed of color difference components CrCb as image data (image data for the projector 120) to be output to the projector 120. The luminance component image 302 and the chrominance component image 303 shown in FIG. 3 are an example of an image represented by luminance component image data and chrominance component image data obtained by dividing input image data. The print image 304 is an example of an output image output from the printer 110 according to the luminance component image data. The projector projected image 305 is an example of an output image output from the projector 120 according to the color difference component image data. Note that RGB signals are converted to Lab signals, L is a luminance component, ab is a color difference component, and luminance component image data consisting of the luminance component L and color difference component image data consisting of the color difference component ab are generated. You may do it.

  Here, the division of the RGB signal will be described in detail. When dividing an RGB signal, the image dividing unit 102 according to the present embodiment converts the RGB. The RGB signal is converted into a YCrCb signal according to a conversion formula (the following formula 1) defined by 709, and Y is divided as a luminance component and CrCb as a color difference component.

  The sRGB RGB signal is converted to an XYZ signal according to the following equation 2, and the XYZ signal is further converted to a Lab signal according to the following equations 3 to 8, and L is divided as a luminance component and ab as a color difference component You may do so.

  Next, the first image generation unit 103 converts the luminance component image data generated by the image division unit 102 into image data (image signal) suitable for the printer 110. Further, the second image generation unit 104 converts the color difference component image data generated by the image division unit 102 into image data (image signal) suitable for the projector 120 (step S203).

  The luminance component image data is image data consisting of the luminance component Y as described above, and more specifically, the color difference components Cr and Cb of the YCrCb signal obtained by Equation 1 are set to 0 which is an intermediate value Image data obtained by Therefore, dividing input image data to generate luminance component image data converts the input image data (RGB signal) into a YCrCb signal according to equation 1, and sets the color difference components Cr and Cb of the YCrCb signal to 0. It is equivalent to Further, generating an image signal suitable for the printer 110 from luminance component image data is equivalent to obtaining an RGB signal by converting a YCrCb signal in which 0 is set to the color difference components Cr and Cb according to the following equation 9: . The color difference component image data is the color difference component image data consisting of the color difference component CrCb as described above, and more specifically, the luminance component Y of the YCrCb signal obtained by the equation 1 has an intermediate value 128 It is image data obtained by setting. Therefore, dividing input image data to generate color difference component image data is equivalent to converting the input image data (RGB signal) according to equation 1, and setting 0 to color difference components Cr and Cb of the YCrCb signal. It is. Further, generating an image signal suitable for the projector 120 from the color difference component image data is equivalent to obtaining an RGB signal by converting the YCrCb signal in which 128 is set to the luminance component Y according to the following equation 9. The luminance component is not limited to 128, and may be another value as long as it is a uniform value. Equation 9 shows that the YCrCb signal is BT. It is a conversion equation used when converting to 709 RGB signals.

  When the printer 110 and the projector 120 input the RGB signal of sRGB, the Lab signal is converted into an XYZ signal according to Equations 10 to 14 below, and the XYZ signals are further converted to RGB signals according to Equation 15 below: It should be converted. At that time, in the case of converting the luminance component image data into the RGB signal, it is sufficient to set the color difference components a and b to 0 which is an intermediate value, respectively. Further, in the case of converting color difference component image data into an RGB signal, conversion may be performed by setting 50 as an intermediate value to the luminance component L. The luminance component is not limited to 50, and may be another value as long as it has a uniform value.

  Finally, the printer 110 performs output (printing) in accordance with the image signal generated by the first image generation unit 103. Further, the projector 120 performs output (projection) according to the image signal generated by the second image generation unit 104 (step S204). At this time, the output image of the printer 110 (print image 304 shown in FIG. 3) is attached to a wall or the like, and the output image of the projector 120 (projector projection image 305 shown in FIG. 3) is projected onto the image. Overlay the image. The reproduced image 306 shown in FIG. 3 is an example of an image obtained by superimposing both images.

  As described above, in the present embodiment, input image data is divided into a luminance component and a color difference component, image data composed of the luminance component is input to the printer, and image data composed of the color difference component is input to the projector. Then, the projected image of the projector is superimposed on the print image output from the printer, and the reproduced image is displayed. When luminance images are superimposed and displayed, particularly when high-frequency luminance images are superimposed and displayed, even if the images of each other are shifted by several pixels, the shift is noticeable. However, in the present embodiment, since the input image data is divided into the luminance component and the color difference component, the luminance images are not superimposed on each other, and temporarily the print image and the projection image of the projector deviate by several pixels. Even in this case, the image shift is less noticeable. That is, according to the present embodiment, in the reproduced image in which the output image of the projector and the printer is superimposed, it is possible to suppress the deterioration of the image quality due to the shift of the image while expanding the dynamic range.

  In the present embodiment, the luminance component is output by the printer and the color difference component is output by the projector. However, the luminance component may be output by the projector and the color difference component may be output by the printer. However, since the luminance is more easily perceived by human eyes than the color difference, it is desirable that the luminance component is output by a device capable of outputting a high resolution image. For example, when the printer can output a high resolution image than the projector, it is preferable to output the luminance component to the printer as in this embodiment.

  Further, the luminance component may be displayed by a high luminance backlight, and the color difference component may be displayed by a transparent film for OHP (Overhead projector). That is, the device connected to the first image generation unit 103 is not limited to the printer, and may be a projector, a display device, an OHP, a high brightness backlight, or the like. Further, the device connected to the second image generation unit 104 is not limited to a projector, and may be a printer, a display device, an OHP, a high brightness backlight, or the like.

  Furthermore, as long as the image output from each device can be superimposed, the combination of each device may be any combination. For example, the projection image of the projector may be superimposed on the display image of the display device using a display device and a projector. In addition, the projected image of the OHP may be superimposed on the print image using a printer and the OHP. Further, two projectors may be used to superimpose the projection image of the other projector on the projection image of one projector.

  Further, in the present embodiment, an image forming system which outputs image data (image signal suitable for each device) from the image processing apparatus 100 to the printer 110 and the projector 120 is exemplified. However, one or both of the image data generated by the first image generation unit 103 and the second image generation unit 104 may be stored in a storage device (for example, a server on a network). . Then, an apparatus other than the image processing apparatus 100 may read out the image data stored in the storage device and output the image data to the corresponding device.

Second Embodiment
In the first embodiment, an example in which the luminance component is displayed by a printer and the color difference component is displayed by a projector has been described. In this embodiment, the color difference component is displayed not only on the projector but also on the printer. In addition, the luminance component is displayed not only on the printer but also on the projector. This expands the color gamut of the system. However, when a luminance component image having a high frequency is displayed on both devices, as described above, there is a risk that the displayed image may be blurred even if the images are shifted by several pixels. Therefore, in the present embodiment, as described below, the frequency of at least the luminance component image displayed on the projector is set low.

  FIG. 4 is a block diagram showing the configuration of the image processing apparatus 200 of the second embodiment. The configuration of the image processing apparatus 200 of the second embodiment is the same as that of the image processing apparatus 100 of the first embodiment. However, in addition to the image input unit 101, the image division unit 102, the first image generation unit 103, and the second image generation unit 104, the second image processing apparatus 200 includes an image distribution unit 401.

  The image sorting unit 401 is disposed downstream of the image dividing unit 102, as shown in FIG. Then, the image distribution unit 401 inputs the luminance component image data and the color difference component image data obtained by the image division unit 102. When the luminance component image data includes a luminance component exceeding the luminance reproducible by the printer 110, the image distribution unit 401 generates low frequency luminance component image data and generates a second image, as will be described later. It passes to the generation unit 104. Similarly, when the color difference component image data includes a color difference component exceeding the color gamut reproducible by the projector 120, the image distribution unit 401 generates low-frequency color difference component image data, as will be described later. It is passed to the first image generation unit 103.

<Processing Flow of Image Processing Device in Second Embodiment>
FIG. 5 is a flowchart showing processing of the image processing apparatus 200 in the second embodiment. The processes of steps S501, S502, and S505 are the same as the processes of steps S201, S202, and S204 in the first embodiment, and thus the description thereof will be omitted.

  In step S 503, the image distribution unit 401 receives the luminance component image data and the color difference component image data from the image division unit 102. Then, the image distribution unit 401 outputs the luminance component image data received from the image division unit 102 to the first image generation unit 103 as it is. Further, the image distribution unit 401 outputs the color difference component image data received from the image division unit 102 to the second image generation unit 104 as it is.

  At this time, as described above, when the input image includes a saturation that can not be reproduced only by the projector 120, the image distributing unit 401 causes the printer 110 to also display the color difference component, so that the low frequency color difference component image data Are generated and output to the first image generation unit 103. In addition, when the input image includes luminance which can not be reproduced only by the printer 110, the image distributing unit 401 generates low frequency luminance component image data to cause the projector 120 to also display the luminance component, and the second image It is output to the generation unit 104.

  When the first image generation unit 103 and the second image generation unit 104 each receive the image data from the image distribution unit 401 in step S504, the first image generation unit 103 and the second image generation unit 104 operate as follows. The first image generation unit 103 combines the luminance component image data received from the image distribution unit 401 with the low frequency color difference component image data. Then, the first image generation unit 103 converts composite image data obtained by combining into an image signal suitable for the printer 110, and outputs the image signal to the printer 110. In addition, the second image generation unit 104 combines the color difference component image data and the low frequency luminance component image data received from the image distribution unit 401. Then, the second image generation unit 104 converts the synthesized image data obtained by the synthesis into an image signal suitable for the projector 120 and outputs it. In addition, since the conversion method to the signal for each device is the same as that of step S203, description is abbreviate | omitted.

<Processing of Image Sorting Unit>
FIG. 6 is a flowchart showing the process of the image distribution unit 401. FIGS. 7 and 8 show how an input image is processed by the image processing apparatus 200 according to the second embodiment. FIG. 9 is a diagram showing the color gamut range of the system.

  The image distribution unit 401 acquires each pixel from the luminance component image data and the color difference component image data received from the image division unit 102 (step S601). The process performed on one pixel acquired from the luminance component image data is the same as the process performed on one pixel acquired from the color difference component image data. Therefore, in the following, processing performed for one pixel acquired from the luminance component image data will be described.

  Next, the image distribution unit 401 sets an initial value of the luminance component of the projector 120 (step S602). The luminance component initial value is Ys = 128 (or Ls = 50). The luminance component initial value is assumed to be stored in advance in a storage device (not shown) or the like included in the image processing apparatus 200. In addition, here, the median value of Y (or the median value of L) is set as the luminance component initial value Ys (or Ls), but other values are set as the luminance component initial value Ys (or Ls) It is also good. Also, the luminance component initial value Ys (or Ls) may be designated by the user.

  Next, the image distribution unit 401 determines whether the pixel acquired in step S601 is outside the basic color gamut of the printer 110 and the projector 120 (step S603). The basic color gamut is a color gamut of the system according to the first embodiment in which the luminance component is displayed by the printer 110 and the color difference component is displayed by the projector. The determination in step S603 is performed by the following method. The image distribution unit 401 determines whether the pixel value of the pixel acquired in step S601 is in the 3DLUT created in advance. Then, if the pixel value is in the 3DLUT (NO in step S603), the image distribution unit 401 determines that the pixel value is in the basic color range, and the process proceeds to step S605. If the pixel value is outside the 3DLUT (YES in step S603), the image distribution unit 401 determines that the pixel value is out of the basic color gamut, and the process proceeds to step S604.

  Here, a method of creating the 3DLUT will be described. First, using the printer 110, an image with several levels from black (Y = 0 or L = 0) to white (Y = 255 or L = 100) is output. Next, with the projector 120 in which the luminance is set to Y = Ys, a patch image with several steps of Cr = -200 to 200 and Cb = -200 to 200 is displayed on the image (output) output from the printer 110. Project Alternatively, a patch image with several steps of a = −200 to 200 and b = −200 to 200 is projected by the projector 120 in which the luminance is set to L = Ls. Furthermore, a patch image previously output by the printer is measured for each projection brightness of the projector to create a 3D LUT.

In step S604, the image distribution unit 401 updates Ys (or Ls) based on the color gamut of the system illustrated in FIG. 9, and the processing proceeds to step S605. An inner diamond-shaped area 901 shown in FIG. 9 shows the color gamut of the system of the first embodiment, ie, the basic color gamut. The outer diamond area shows the color gamut of the system of the second embodiment. A region 902 indicates a region in the luminance range of the system of the second embodiment that is larger than that of the system of the first embodiment. An area 903 indicates an area in which the luminance component is smaller than the color gamut of the system of the first embodiment in the color gamut of the system of the second embodiment. An area 904 indicates an area in the color gamut of the system according to the second embodiment that has a color difference component larger than that of the system according to the first embodiment. That is, the areas 902 and 903 are color gamuts that can not be reproduced only by the printer 110, and represent color gamuts that can be reproduced by using the printer 110 and the projector 120 together. An area 904 is a color gamut which can not be reproduced only by the projector 120, and represents a color gamut which can be reproduced by using the printer 110 and the projector 120 in combination. When the luminance component of the pixel acquired in step S 601 belongs to the area 902, the image distribution unit 401 updates Ys (or Ls) using Equation 16 below, and when the luminance component belongs to the area 903, Update Ys (or Ls) using Equation 17 below. Numerical values such as “8” and “5” in Equation 16 and Equation 17 can be designated by the user, and are stored in advance in a storage device (not shown) or the like included in the image processing apparatus 200.
Ys = Ys + 8 (or Ls = Ls + 5) (Equation 16)
Ys = Ys-8 (or Ls = Ls-5) (Expression 17)

  In step S605, the image distribution unit 401 creates low-frequency luminance component image data using Ys (or Ls). More specifically, the image distribution unit 401 creates image data in which Ys (or Ls) is set at the same pixel position as the pixel acquired in step S601. The low frequency luminance component image data is generated by performing this process for all pixels of the luminance component image data. The projector luminance component image 705 shown in FIG. 7 is an example of an image represented by low frequency luminance component image data.

  In step S606, the image sorting unit 401 determines whether the process has been completed for all pixels. If the process has been completed for all pixels (YES in step S606), the process ends. If the process has not been completed for all pixels (NO in step S606), the process returns to step S601.

  As described above, as shown in FIG. 7, the projector luminance component image 705 is generated from the luminance component image 702. The projector luminance component image 705 is a low frequency luminance component image in which pixel values of 128, 136 (= 128 + 8), 120 (= 128-8) are set for each pixel. The printer luminance component image 704 shown in FIG. 7 is an image represented by the luminance component image data transferred from the image distribution unit 401 to the first image generation unit 103, and is the same as the luminance component image 702. The printer image 708 is an example of an image represented by composite image data obtained by combining the luminance component image data and the low frequency color difference component image data.

  Further, the image distribution unit 401 similarly performs the above-described processing on each pixel of the color difference component image data to generate low frequency color difference component image data. The printer color-difference component image 706 shown in FIG. 7 is an example of an image indicated by low-frequency color-difference component image data. When the above processing is performed on each pixel of the color difference component image data, the color difference component initial value of the printer 110 may be set in step S602. The color difference component initial value is Crs = Cbs = 0 (or as = bs = 50). In step S603, when the color difference component of the pixel acquired in step S601 belongs to the region 904 on the plus side (the right side in FIG. 9), Crs and Cbs (or as and bs) using the same equation as equation 16. ) Should be updated. Further, in step S603, when the color difference component of the pixel acquired in step S601 belongs to the area 904 on the minus side (left side in FIG. 9), Crs and Cbs (or as and bs) using the same equation as equation 17. Should be updated. The projector color-difference component image 707 shown in FIG. 7 is an image represented by the color-difference component image data transferred from the image distribution unit 401 to the second image generation unit 104, and is the same as the color-difference component image 703. The projector image 709 is an example of an image represented by composite image data obtained by combining the chrominance component image data and the low frequency luminance component image data.

  As described above, in the present embodiment, since the luminance component of the input image is also output to the projector 120, the dynamic range of the reproduced image can be further expanded. Thus, for example, when displaying an image obtained by photographing a scene in which the spotlight is on the subject (person) as in the input image 801 shown in FIG. It can be faithfully reproduced. Images 802 to 809 shown in FIG. 8 are the same as the images 702 to 709. That is, the images 802 to 809 correspond to each of the images indicated by the image data generated in the processing process when the image processing in the present embodiment is applied to the input image 801. In addition, the description about the images 802-809 is abbreviate | omitted for the simplification of description.

  Further, in the present embodiment, when the luminance component of the input image is output to the projector 120, a low frequency luminance component image is generated and output to the projector 120 so that the high frequency luminance component images are not superimposed. It is like that. Therefore, even when the luminance component image is output to both the printer 110 and the projector 120, the deterioration of the image quality due to the pixel shift can be made less noticeable.

  Further, in the present embodiment, since the color difference component of the input image is also output to the printer 110, the color gamut in the reproduced image can be further expanded. Therefore, for example, when the color of the body of the subject (car) or the color of characters such as "ABC" in the input image 701 shown in FIG. 7 is a high saturation color (fluorescent yellow green, fluorescent orange, etc.) However, these colors can be reproduced more faithfully in the reproduced image. In the present embodiment, when the low frequency color difference component image data is generated, low frequency image data is generated by the same method as in the case of generating the low frequency luminance component image data. However, when the high-frequency color difference component images are superimposed, the pixel shift is less noticeable as compared with the case where the high-frequency luminance component images are superimposed. Therefore, the low frequency chrominance component image data does not necessarily have to have a frequency as low as that of the low frequency luminance component image data, and may be generated by a method other than the above.

(Other embodiments)
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

102 image division unit 103 first image generation unit 104 second image generation unit

Claims (15)

An image processing apparatus in an image forming system which forms an image represented by input image data by superimposing and displaying an output image by a first device and an output image by a second device based on input image data. ,
A division unit that divides the input image data into a color difference component and a luminance component;
First generation means for generating image data for the first device for causing the first device to output the output image based only on the luminance component without using the color difference component;
Second generation means for generating image data for the second device for causing the second device to output the output image based only on the color difference component without using the luminance component; An image processing apparatus characterized by having. The first generation means sets the luminance indicated by the luminance component of the corresponding pixel position of the input image data to the luminance component of each pixel position of the image data for the first device. Set a predetermined color difference to the color difference component,
The second generation means sets the color difference indicated by the color difference component of the corresponding pixel position of the input image data to the color difference component of each pixel position of the image data for the second device. The image processing apparatus according to claim 1, wherein a predetermined luminance is set to the luminance component. The predetermined color difference is an intermediate value of the color difference that can be set to the image data for the first device, and the predetermined brightness is an intermediate value of the brightness that can be set to the image data for the second device. It is a value. The image processing device according to claim 2. The first generation means generates, based on the luminance component, luminance component image data of lower frequency than the image data for the first device,
The second generation means is
The composite image data obtained by combining the image data for the second device generated based on only the color difference component without using the luminance component, and the low frequency luminance component image data, is newly described. The image processing apparatus according to any one of claims 1 to 3, wherein the image data for the second device is used. The first generation means generates the low frequency luminance component image data when the input image data includes a luminance component indicating luminance outside the color gamut reproducible by the first device. The image processing apparatus according to claim 4, characterized in that: The first generation means is
With respect to the input image data, it is determined, for each pixel position, whether or not the luminance indicated by the luminance component of the pixel position is within a color range reproducible by the first device;
A first predetermined brightness is set for a pixel position having a brightness component indicating a brightness within a color range reproducible by the first device, and a brightness exceeding the color gamut reproducible by the first device is set. For a pixel position having a luminance component indicating a second luminance that is greater than the first luminance, and a pixel position having a luminance component that indicates a luminance below the color gamut reproducible by the first device The image processing apparatus according to claim 4 or 5, wherein the low frequency luminance component image data is generated by setting a third luminance smaller than the first luminance. . The image processing apparatus according to claim 6, wherein the first predetermined brightness is an intermediate value of the brightness that can be set to the image data for the second device. The second generation unit generates color difference component image data having a frequency lower than that of the image data for the second device, based on the color difference component.
The first generation means is
The composite image data obtained by combining the image data for the first device generated based only on the luminance component without using the color difference component and the color difference component image data of the low frequency is newly described. The image processing apparatus according to any one of claims 1 to 7, wherein the image processing apparatus is an image data for a first device. The second generation unit generates the low-frequency color difference component image data when the input image data includes a color difference component indicating a color difference outside the color gamut reproducible by the second device. The image processing apparatus according to claim 8, characterized in that: The second generation means is
With respect to the input image data, it is determined, for each pixel position, whether or not the color difference indicated by the color difference component of the pixel position is within a color range reproducible by the second device.
A first predetermined color difference is set for a pixel position having a color difference component indicating a color difference within a reproducible color range by the second device, and a color difference exceeding the color gamut reproducible by the second device For a pixel position having a color difference component indicating a second color difference larger than the first color difference, and a pixel position having a color difference component indicating a color difference below the color gamut reproducible by the second device 10. The image processing apparatus according to claim 8, wherein the low-frequency color difference component image data is generated by setting a third color difference smaller than the first color difference. . The image processing apparatus according to claim 10, wherein the predetermined first color difference is an intermediate value of the color difference that can be set to the image data for the first device. The image processing apparatus according to any one of claims 1 to 11, wherein the first device can output an image having a resolution higher than that of the second device. The image processing apparatus according to any one of claims 1 to 12, wherein the first device is a printer and the second device is a projector. An image processing method in an image forming system for forming an image represented by the input image data by superimposing and displaying an output image by a first device and an output image by a second device based on input image data. ,
A division step of dividing the input image data into a color difference component and a luminance component;
A first generation step of generating image data for the first device for causing the first device to output the output image based only on the luminance component without using the color difference component;
A second generation step of generating image data for the second device for causing the second device to output the output image based only on the color difference component without using the luminance component; An image processing method comprising:   A program for causing a computer to function as the image processing device according to any one of claims 1 to 13.