JP4114072B2 - Image processing apparatus, image processing method, image processing program, and storage medium - Google Patents

Description

  The present invention relates to color processing on a color image, and for example, relates to an image processing technique for performing processing on an input image in accordance with the visual characteristics of an observer when the input image is visualized. The present invention also relates to an image processing technique for compressing a color gamut so as to match the color gamut of an output device, for example, when a color image is converted into a form suitable for output by an output unit.

  Physically there is no color in light, it is the observer's psychological response. That is, the color appearance varies depending on the individual. It is thought that this is mainly due to differences in the retinal structure between observers, especially the ratio of cones that are sensors that perceive color, and the wavelength at which cones have the highest sensitivity. It has been reported that not only such physiological differences but also past experiences and environments have an impact.

  Just because we call with the same color name, there is no guarantee that we perceive it as exactly the same color. In fact, the most reddish and blueish colors are experimentally determined and expressed with the same chromaticity, but it is known that there are individual differences.

  Incidentally, in an image forming apparatus such as a copying machine, since an original exists, it has been required to faithfully reproduce the original chromaticity. On the other hand, for a CG, an electronic input image, or the like that does not have an original, the created hue changes depending on the visual characteristics of the observer. As a result, individual differences are also included in the formed image, so there is no guarantee that the image originally intended by the observer or designer can be transmitted. Conventionally, there is no image processing apparatus that includes the characteristics of the color appearance of an individual such as an observer or designer and can acquire the same impression and the same color appearance without depending on the observer.

  For example, regarding the brightness of an image, when an image is presented on a display device such as a CRT, a highly saturated (bright) color is perceived brightly even if the luminance is low. However, how brightly it is perceived depends on the observer. This is called brightness efficiency and there are individual differences. For example, when the point where the electronic color chart displayed on the CRT is not perceived as the object surface is obtained, there is an individual difference in the luminance, and this individual difference is almost equal to the luminance when the brightness efficiency of the observer is measured. It is known from Non-Patent Document 1 and the like that there are individual differences corresponding to individual differences.

  When visual characteristics are taken into consideration, the mainstream method is to perform a psychophysical experiment using a large number of subjects, obtain an average value thereof, and use it as a representative value. A typical example is the visual characteristics of a fictitious observer called a standard observer defined by the CIE (International Commission on Illumination). This is currently used when deriving values called tristimulus values that are generally used in the field of color engineering, and the color space is also defined based on these values.

  On the other hand, it has been reported that two colors that are equalized so that the appearances of two colors having different spectral distributions are exactly the same are not necessarily consistent when expressed by these tristimulus values. In addition, it has been reported that these color matching conditions differ depending on the observer, and this is not acceptable because the visual characteristics of each observer are negligible with the average value defined as a standard observer. It suggests that there is not.

  As described above, there are individual differences in the degree of brightness perception. Therefore, even if the same image is observed, the impression received is different and the brightness to be felt is different. Further, as described above, whether or not the electronic color chart displayed on the CRT is perceived by the color of the object surface (surface color mode) depends on the observer. Therefore, a display device that absorbs individual differences in the visual characteristics of the observer can make the impression received on the same image substantially the same regardless of the observer.

  As a conventional technique, as disclosed in Patent Document 1, for example, a technique for adjusting the brightness of images on monitors and matching the brightness between monitors has been proposed. However, with such a technique, even if the brightness between monitors can be adjusted, a display device that receives the impression of the same brightness reflecting the characteristics of the observer observing it cannot be realized.

  Further, color gamut mapping is one of color image processes. In many cases, the color gamut is different because the characteristics are different between the image input device and the image output device. When an image is input / output between devices having different color gamuts, there is a problem in that colors between an input image and an image acquired as a result of output do not match. Further, even if the color can be input by the image input device, the color may not be output by the image output device. In such a case, it is necessary to convert the color into a color that can be output by the image output device. Such color conversion is performed by a color gamut mapping process. Various methods have been proposed as the color gamut mapping method. In these, it is common to determine a conversion parameter so that a perceived hue is maintained, and the conversion parameter is uniquely determined.

  However, as described above, it is known that there is an individual difference in color perception, and the color perceived by the same hue varies depending on the observer. As described above, if the color gamut mapping process is performed under conditions that depend on the observer, there is no guarantee that a satisfactory color gamut mapping process will be performed because it is different from the equi-hue condition of the other person.

  Conventionally, for example, Patent Document 2 proposes a method of selecting an appropriate color gamut mapping method according to the type of image to be output. However, in such a method, although different parameters can be selected depending on the line drawing, halftone image, etc., since the color processing coefficient is uniquely determined without considering the color perception characteristics of the observer, Even the hue perception characteristic caused by the difference of the observer cannot be dealt with. In addition, it is not possible to deal with an equal hue condition that changes with a change in illumination condition or the like.

JP 2002-333874 A JP 2002-218271 A Yamauchi, Uchikawa, Kuriki, “The Journal of the Institute of Image Information and Television Engineers”, 1998, Vol. 52, no. 2, p. 227-234

  The present invention has been made in view of the above-described circumstances, and provides an image processing apparatus and an image processing method for performing color processing so that each observer sees the same color when the visualized image is referred to. It is for the purpose. It is another object of the present invention to provide an image processing program for causing a computer to execute such an image processing method, and a storage medium storing such an image processing program.

  The present invention relates to an image processing apparatus and an image processing method for converting an input image into an output image for visualizing the input image, and a visual characteristic related to brightness perception as a visual characteristic of an observer observing the visualized image. Alternatively, the correction coefficient is determined by the correction coefficient determining means according to the result of extracting the features related to the perception of equal hue by the observer, and color conversion from the input image to the output image for visualizing the input image is performed according to the correction coefficient. This is performed by correction processing means.

  Here, with regard to the visual characteristics related to brightness perception, brightness efficiency is acquired as the brightness perception by adjusting the brightness of the presented multiple colors to be equal to the reference color by the observer. In addition, the feature related to the equal hue perception is extracted by adjusting the saturation of a representative color so that the observer can perceive the same hue. Further, user condition setting means for acquiring the visual characteristics of the observer is further provided, and the correction coefficient is determined according to the visual characteristics of the observer acquired by the user condition setting means.

  In such a configuration, a plurality of correction coefficients can be stored in the correction coefficient storage means, and a correction coefficient can be selected from them.

  At this time, a plurality of functions for correcting the image are stored in the correction coefficient storage unit, and the brightness efficiency correction gain is obtained from the brightness efficiency, and the function is selected from the correction coefficient storage unit and selected. A correction coefficient can be determined from the function and the obtained brightness efficiency correction gain. The function can be selected, for example, by acquiring information related to the environment for observing the visualized image and according to the information related to the environment.

  Furthermore, for example, it is possible to take into account peripheral stimuli when referring to a visualized image, such as a window frame, to acquire information on peripheral stimuli, and to take this into consideration to determine a correction coefficient.

  As color conversion performed by the color correction processing means, color gamut compression processing can be performed. In this case, a correction coefficient for color gamut compression processing is determined. The correction coefficient at this time can be determined according to the set color temperature of the image to be visualized. Further, the color conversion process can be configured to perform a common color gamut compression process after performing a correction process depending on the observer according to the correction coefficient.

  Further, the present invention is an image processing program executed by a computer, and is characterized by causing a computer to execute the function of the image processing apparatus of the present invention as described above or the image processing method of the present invention. Furthermore, the present invention is a computer-readable storage medium that stores such an image processing program.

  According to the present invention, since color conversion is performed in consideration of the visual characteristics of the observer, there is an effect that an image can be visualized so that each observer perceives it as almost the same color.

  FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, 11 is a visual characteristic individual difference storage unit, 12 is a user condition setting unit, 13 is an environment information acquisition unit, 14 is a peripheral stimulus information acquisition unit, 15 is a visual characteristic individual difference correction coefficient determination unit, and 16 is a color correction process. Reference numeral 17 denotes a display device. In this example, a display device 17 is shown as an example of a device for visualizing an image. However, the present invention is not limited to this, and a printer or another output device may be used.

  The visual characteristic individual difference storage unit 11 holds a large number of correction coefficients used when the color correction processing unit 16 performs correction processing corresponding to visual characteristics that are different for each observer. Note that when the correction coefficient is generated by the visual characteristic individual difference correction coefficient determination unit 15 described later, a configuration without the visual characteristic individual difference storage unit 11 is also possible.

  The user condition setting unit 12 acquires the visual characteristics of an observer who observes the image displayed on the display device 17. For example, the visual characteristics relating to the brightness perception of the observer and the result of color adjustment so that the observer perceives the same hue can be used as the visual characteristics. At this time, since the visual characteristics vary depending on the color temperature of the illumination light, the visual characteristics under the standard illumination are maintained as standard values, and the adaptation state under the standard illumination and the adaptation under the given illumination are maintained. The visual characteristics under given lighting may be obtained from the state. Of course, the visual characteristics of the observer may be acquired by other methods. Further, when the visual characteristics of the observer are acquired in advance, the corresponding visual characteristics may be acquired, for example, by inputting information specifying the observer. Furthermore, when only a specific observer uses, the user condition setting unit 12 may not be provided during normal color conversion.

  The environment information acquisition unit 13 acquires information related to an environment in which an image displayed on the display device 17 is observed, for example, an environment such as the color temperature of illumination light or external light. The peripheral stimulus information acquisition unit 14 also displays peripheral stimuli of the image displayed on the display device 17, for example, when the image is displayed in a window, the color and thickness of the window frame, and the color of the edge portion of the display device 17. The surrounding conditions of various images, such as thickness and thickness, are acquired as information on peripheral stimuli. The environmental information acquisition unit 13 and the peripheral stimulus information acquisition unit 14 can be provided as appropriate.

  The visual characteristic individual difference correction coefficient determination unit 15 determines a correction coefficient to be used when the color correction processing unit 16 performs color conversion based on the visual characteristics of an observer who observes the image displayed on the display device 17. To do. At this time, the visual characteristics of the observer may be acquired by a method other than acquiring from the user condition setting unit 12. In addition, when determining the correction coefficient, information on the environment and information on the peripheral stimulus acquired by the environment information acquisition unit 13 and the peripheral stimulus information acquisition unit 14 can be taken into consideration. Further, in this example, the correction coefficient is determined by selecting an optimum correction coefficient from the correction coefficients held in the visual characteristic individual difference storage unit 11. For example, the correction coefficient may be generated by a predetermined function or the like. The determined correction coefficient is transferred to the color correction processing unit 16.

  The color correction processing unit 16 performs color conversion from an input image to an output image for visualizing the input image according to the correction coefficient determined by the visual characteristic individual difference correction coefficient determination unit 15. In this example, the output image is transferred to the display device 17, displayed, and presented to the observer. Since the correction coefficient determined by the visual characteristic individual difference correction coefficient determination unit 15 is determined according to the visual characteristics of the observer, the color is set so that the same color is perceived as the same color by each observer. Conversion can be performed.

  That is, even when the same input image is displayed, the color conversion processing is uniformly performed and displayed on the display device 17, and when the image is observed by the observer, it is perceived from the difference in the visual characteristics of each observer. Each color will be different. In the present invention, by performing color conversion according to the visual characteristics of each observer, each observer perceives the same input image as the same color.

  Note that the color conversion processing includes not only color correction processing based on the visual characteristics of the observer but also various color processing such as color gamut compression processing, gamma conversion processing, and color space conversion processing described later. .

  FIG. 3 is a block diagram showing a second embodiment of the present invention. In the figure, the same parts as those in FIG. 31 is a brightness efficiency correction coefficient storage unit, and 32 is a brightness efficiency correction coefficient determination unit. In the second embodiment, an example is shown in which visual characteristics related to brightness perception are used as the visual characteristics of the observer. In particular, here, brightness efficiency is obtained as brightness perception, a correction coefficient is determined according to the brightness efficiency, and color conversion processing is performed.

  The brightness efficiency correction coefficient storage unit 31 holds correction coefficients corresponding to various brightness efficiencies. In particular, in this example, chromaticity characteristics are stored in advance in the form of a function with white as a reference, and are used for obtaining a correction coefficient together with a brightness efficiency correction gain obtained from brightness efficiency as described later.

  The user condition setting unit 12 acquires the brightness efficiency as the brightness perception of the observer. For example, the observer can visually adjust the brightness of the presented multiple colors to be equal to the reference color, and the brightness efficiency can be obtained as the brightness perception from the result of the adjustment. FIG. 4 is an explanatory diagram of an example of an adjustment screen presented to the observer. For example, as shown in FIGS. 4A and 4B, the reference color and the test color may be displayed side by side, and the test color may be adjusted so that the brightness of the reference color and the test color are the same. For example, white (gray) is used as the reference color, and the test color is adjusted so as to have the same brightness as that white. The test color and white luminance value at this time can be used as the brightness efficiency. FIG. 5 is a chromaticity point diagram showing an example of a test color used when obtaining the brightness efficiency, and FIG. 6 is a chromaticity diagram showing an example of the obtained brightness efficiency. The adjustment work as described above is performed for a plurality of colors as shown in FIG. 5, for example, and the brightness efficiency is obtained. The brightness efficiency thus obtained is as shown in FIG. 6, for example.

  The brightness efficiency correction coefficient determination unit 32 determines a correction coefficient for converting the luminance and color information of the image according to the magnitude of the brightness efficiency. Here, the function stored in the brightness efficiency correction coefficient storage unit 31 is selected according to the information about the environment acquired by the environment information acquisition unit 13 or the information about the peripheral stimulus acquired by the peripheral stimulus information acquisition unit 14. To do. And the function selected with respect to the brightness efficiency acquired by the user condition setting part 12 is applied, a brightness efficiency correction gain is calculated | required, and it determines as a correction coefficient.

  Note that the brightness efficiency correction coefficient determination unit 32 not only determines a correction coefficient to be automatically corrected based on the brightness efficiency of the observer, but also weakens it because, for example, the vividness is too strong. You may comprise so that an observer can adjust correction amount. Further, since the correction coefficient determined by the brightness efficiency correction coefficient determination unit 32 is considered to be the same correction coefficient in principle if the observer is the same in the same environment, the determined correction coefficient is associated with the observer and the environment. The brightness efficiency correction coefficient storage unit 31 may be stored in advance, and the observer may be specified and the correction coefficient may be called from the brightness efficiency correction coefficient storage unit 31 from the next time onward. Furthermore, when a plurality of observers observe the same display device at the same time, the brightness efficiency of each observer is obtained, and the correction coefficient is determined using the average value as a representative value. Is also possible.

  FIG. 7 is a block diagram showing a third embodiment of the present invention. In the figure, the same parts as those in FIG. 41 is a color gamut compression parameter storage unit, 42 is a color gamut compression parameter selection unit, and 43 is an image output unit. In the third embodiment, the color correction processing unit 16 includes a color gamut compression process. In this example, a case where an image output unit 43 such as a printer is used as an apparatus for visualizing the processed image is shown.

  The color gamut compression parameter storage unit 41 stores in advance parameters (correction coefficients) for different color gamut compression assuming different set color temperatures of different image output units 43 and various observer visual characteristics.

  As in the second embodiment described above, the user condition setting unit 12 adjusts the reference color with respect to a number of hues under the condition in which the standard color is actually presented as shown in FIG. It is possible to make the observer create an equi-hue state. As a result, since the color value to be output to the image output unit 43 is known, the chromaticity can be calculated and the optimum parameter can be selected by the color gamut compression parameter selection unit 42 described later. In addition to such a method, a processing result using a certain color gamut compression parameter is previewed in advance, and if the viewer is not satisfied, the fact is notified to the color gamut compression parameter selection unit 42 to select a different color gamut compression parameter. As described above, the viewer can also select the confirmation function and the color conversion condition. In this case, the color gamut compression parameter selected by the observer is stored in the color gamut compression parameter storage unit 41 in association with the observer, and information specifying the observer is set from the user condition setting unit 12. It is also possible to configure as described above.

  The environment information acquisition unit 13 acquires information on the set color temperature of the image visualized in the image output unit 43 as information related to the environment. In addition, you may comprise so that the information regarding various environments, such as the color temperature of an illumination light source, may be acquired. Note that the surrounding stimulus information acquisition unit 14 (not shown) may acquire information about the surrounding stimulus (for example, a frame) as information related to the peripheral stimulus.

  The color gamut compression parameter selection unit 42 determines a color gamut compression parameter (correction coefficient) for the color gamut compression processing performed in the color correction processing unit 16, and the observer's set by the user condition setting unit 12. Color gamut compression according to the conditions and information about the environment such as the set color temperature and ambient light of the image to be visualized acquired by the environment information acquisition unit 13, or information about the peripheral stimulus acquired by the peripheral stimulus information acquisition unit 14 The most appropriate color gamut compression parameter stored in the parameter storage unit 41 is selected.

  In this example, the color correction processing unit 16 performs color gamut compression processing according to the color gamut compression parameter determined by the color gamut compression parameter selection unit 42. Various known methods can be adopted as the color gamut compression method. For example, when the color gamut is different, various methods can be applied, such as keeping the hue and saturation and making the color closest to the lightness direction, or keeping the hue and lightness and making the color closest to the saturation direction. can do. The color correction processing unit 16 can perform various color processes including the color gamut compression process.

  As described above, the perceived color varies depending on the observer depending on the visual characteristics of the observer. For this reason, when color gamut compression is performed with the color gamut compression direction and compression amount constant, the way the color is felt after compression varies depending on the observer, and the color that appears to be optimal after color gamut compression may also vary. is assumed. Therefore, by determining the color gamut compression parameters according to the visual characteristics of the observer and performing the color gamut compression processing as in this embodiment, it is possible to perform compression to the optimum color for each observer.

  FIG. 8 is a block diagram showing a modification of the third embodiment of the present invention. In the figure, the same parts as those in FIG. 51 is a hue conversion parameter storage unit, 52 is a hue conversion parameter selection unit, 53 is an observer-dependent hue conversion processing unit, and 54 is a color gamut compression processing unit. In the modification of the third embodiment, an example is shown in which the color correction processing unit 16 is separated from a portion that performs correction processing depending on the visual characteristics of the observer and a portion that performs common color processing. . In particular, in this example, an example in which equal hue conditions are corrected is shown as correction processing depending on the observer.

  The hue conversion parameter storage unit 51 holds a correction coefficient for performing hue conversion depending on the visual characteristics of the observer. The correction coefficient may be set in advance, or the correction coefficient set by the next user condition setting unit 12 may be stored in association with the observer. Further, when the correction coefficient is calculated and determined each time, the hue conversion parameter storage unit 51 may not be provided.

  The user condition setting unit 12 changes the saturation of representative colors (especially blue and red) and adjusts the stimulus so that it is perceived to have a uniform hue in several stages. Features relating to perception are extracted and passed to the hue conversion parameter selection unit 52. Alternatively, when a correction coefficient is stored in advance in the hue conversion parameter storage unit 51 for each observer, information specifying the observer may be passed to the hue conversion parameter selection unit 42.

  The hue conversion parameter selection unit 52 determines a correction coefficient to be an equal hue according to the information passed from the user condition setting unit 12. The correction coefficient may be determined by selecting a correction coefficient stored in the hue conversion parameter storage unit 51, or by preparing a standard function determined from the chromaticity, and adjusting only the gain from the adjustment result. It is also possible to configure so that the correction coefficient is created every time by obtaining.

  The observer-dependent hue conversion processing unit 53 performs a hue conversion process according to the correction coefficient selected by the hue conversion parameter selection unit 52. By this processing, the hue fluctuation portion depending on the visual characteristics of each observer is corrected. Therefore, the subsequent processes may be common processes, and the color gamut compression process can be executed as a common process not depending on the observer.

  Therefore, the color gamut compression parameter storage unit 41 stores a common color gamut compression parameter, information related to the environment acquired by the environment information acquisition unit 13, and also related to the peripheral stimulus acquired by the peripheral stimulus information acquisition unit 14. The optimum color gamut compression parameter may be selected by the color gamut compression parameter selection unit 42 according to the information and the color gamut compression processing unit 54 may perform the color gamut compression processing according to the color gamut compression parameter.

  Thus, by separating the process depending on the observer, the configuration of each unit can be simplified, and the existing process can be applied to the color gamut compression process and the like.

  FIG. 9 is an explanatory diagram of an example of a computer program and a storage medium storing the computer program when the function of the image processing apparatus or the image processing method of the present invention is realized by the computer program. In the figure, 101 is a program, 102 is a computer, 111 is a magneto-optical disk, 112 is an optical disk, 113 is a magnetic disk, 114 is a memory, 121 is a magneto-optical disk apparatus, 122 is an optical disk apparatus, and 123 is a magnetic disk apparatus.

  A part or all of the functions of the units other than the display device 17, the image output unit 43, and the storage units described in the above-described embodiments can be realized by a program 101 that can be executed by a computer. In that case, the program 101 and data used by the program can be stored in a computer-readable storage medium. A storage medium is a signal format that causes a state of change in energy such as magnetism, light, electricity, etc. according to the description of a program to a reader provided in the hardware resources of a computer. Thus, the description content of the program can be transmitted to the reading device. For example, a magneto-optical disk 111, an optical disk 112 (including a CD and a DVD), a magnetic disk 113, a memory 114 (including an IC card and a memory card), and the like. Of course, these storage media are not limited to portable types.

  By storing the program 101 in these storage media and mounting these storage media in, for example, the magneto-optical disk device 121, optical disk device 122, magnetic disk device 123, or memory slot (not shown) of the computer 102, the computer 101 The program 101 can be read to execute the function of the image processing apparatus or the image processing method of the present invention. Alternatively, a storage medium may be attached to the computer 102 in advance, and the program 101 may be transferred to the computer 102 via a network, for example, and the program 101 may be stored and executed on the storage medium.

  Of course, some functions may be configured by hardware, or all may be configured by hardware. In addition, each storage unit in each of the above-described embodiments can be configured using a storage device of another device connected in the computer 102 or by a network.

It is a block diagram which shows the 1st Embodiment of this invention. It is a block diagram which shows the 2nd Embodiment of this invention. It is explanatory drawing of an example of the adjustment screen shown to an observer. It is a chromaticity point diagram showing an example of a test color used when obtaining brightness efficiency. It is a chromaticity diagram showing an example of the calculated brightness efficiency. It is a block diagram which shows the 3rd Embodiment of this invention. It is a block diagram which shows the modification of the 3rd Embodiment of this invention. FIG. 2 is an explanatory diagram of an example of a computer program and a storage medium storing the computer program when the function of the image processing apparatus or the image processing method of the present invention is realized by the computer program.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Visual characteristic individual difference memory | storage part, 12 ... User condition setting part, 13 ... Environmental information acquisition part, 14 ... Peripheral stimulus information acquisition part, 15 ... Visual characteristic individual difference correction coefficient determination part, 16 ... Color correction process part, 17 DESCRIPTION OF SYMBOLS ... Display apparatus, 21 ... Visual characteristic individual difference correction process part, 22 ... Visual characteristic process part, 23 ... Color correction part, 31 ... Brightness efficiency correction coefficient memory | storage part, 32 ... Brightness efficiency correction coefficient determination part, 41 ... Color Gamut compression parameter storage unit 42 ... color gamut compression parameter selection unit 43 43 image output unit 51 ... hue conversion parameter storage unit 52 ... hue conversion parameter selection unit 53 53 observer-dependent hue conversion processing unit 54 ... color Area compression processing unit, 101 ... program, 102 ... computer, 111 ... magneto-optical disk, 112 ... optical disk, 113 ... magnetic disk, 114 ... memory, 121 ... magneto-optical disk device, 122 ... Disk device, 123 ... magnetic disk device.

Claims (24)

User condition setting means for acquiring visual characteristics related to brightness perception as visual characteristics of an observer observing a visualized image in an image processing apparatus that converts an input image into an output image for visualizing the input image ; Correction coefficient determining means for determining a correction coefficient based on the visual characteristics acquired by the user condition setting means, and color conversion from the input image to the output image in accordance with the correction coefficient determined by the correction coefficient determining means have a color correction processing means for performing, the user condition setting means observer visually by a plurality of colors brightness presented is adjusted to be equal to the reference color, as the brightness perception An image processing apparatus characterized by acquiring brightness efficiency . Wherein the correction factor determining means according to claim 1, characterized in that to determine the correction coefficient for converting the image brightness, the color information according to the magnitude of the brightness efficiency obtained by said brightness perception Image processing device. The user condition setting means, white is used as reference color image according to claim 1 or claim 2 observer, characterized by using as the brightness efficiency colors and white luminance values combined visually Processing equipment. The image processing apparatus further includes a correction coefficient storage unit that stores a plurality of functions for correcting the image, and the correction coefficient determination unit obtains a brightness efficiency correction gain from the brightness efficiency and functions from the correction coefficient storage unit. select image processing apparatus according to any one of claims 1 to 3, characterized in that to determine the correction coefficient from the function number and the brightness efficiency correction gain. Furthermore, it has environment information acquisition means for acquiring information about the environment for observing the visualized image, and the correction coefficient determination means functions from the correction coefficient storage means according to the information about the environment acquired by the environment information acquisition means. The image processing apparatus according to claim 4 , wherein the image processing apparatus is selected. In an image processing apparatus that performs conversion from an input image to an output image for visualizing the input image, color adjustment is performed so that the observer perceives it as a uniform hue as a visual characteristic of the observer observing the visualized image User condition setting means for extracting features related to equal hue perception from the results obtained, correction coefficient determination means for determining correction coefficients using features related to equal hue perception extracted by the user condition setting means, and the correction coefficient determination means the have a color correction processing means for performing color conversion from the input image to the output image in accordance with the correction coefficient in determined, the user condition setting means is perceived equal hue with varying saturation representative color An image processing apparatus characterized by extracting features related to equal hue perception by adjusting an observer to such a state . The image processing apparatus according to claim 6 , wherein the color correction processing unit performs a common color gamut compression process after performing a correction process depending on an observer according to the correction coefficient. The correction coefficient determination means further determines a correction coefficient for color gamut compression processing according to the result of the color adjustment, and the color correction processing means determines a color according to the correction coefficient determined by the correction coefficient determination means. The image processing apparatus according to claim 6 , wherein color processing including area compression processing is performed. The image processing apparatus according to claim 8 , wherein the correction coefficient determination unit determines the correction coefficient according to a set color temperature of an image to be visualized. The correction coefficient storage means further stores a plurality of correction coefficients, and the correction coefficient determination means selects a correction coefficient to be passed to the color correction processing means by selecting from among the correction coefficients stored in the correction coefficient storage means. the image processing apparatus according to any one of claims 1 to 9, characterized in that the determining. Furthermore, it has peripheral stimulus information acquisition means for acquiring information related to peripheral stimuli when referring to a visualized image, and the correction coefficient determination means takes into account information related to peripheral stimuli acquired by the peripheral stimulus information acquisition means. determining a correction coefficient Te image processing apparatus according to any one of claims 1 to 1 0, characterized in. In the image processing method for converting an input image into an output image for visualizing the input image, the user condition setting means obtains a visual characteristic related to brightness perception as a visual characteristic of an observer observing the visualized image. The correction coefficient determining means determines a correction coefficient based on the acquired visual characteristics, and the color correction processing means performs color conversion from the input image to the output image according to the determined correction coefficient , An image processing method characterized in that a brightness efficiency is acquired as the brightness perception by an observer visually adjusting the brightness of a plurality of presented colors to be equal to a reference color . Examples correction coefficient, wherein the calculated brightness efficiency as the brightness perception, the brightness efficiency of the image depending on the size brightness to claim 1 2, characterized in that to determine the correction coefficient for converting the color information The image processing method as described. 14. The image processing method according to claim 12 , wherein white is used as a reference color as the brightness efficiency, and a luminance value of white and a color visually adjusted by an observer is used. Further, a plurality of functions for correcting the image are stored in the correction coefficient storage means, and when the correction coefficient is determined, a brightness efficiency correction gain is obtained from the brightness efficiency, and the correction coefficient storage is stored. select a function from the unit, the image processing method according to any one of claims 1 2 to claims 1-4, characterized in that to determine the correction coefficient from the function number and the brightness efficiency correction gain. Further, the environment information acquisition unit acquires information on an environment for observing the visualized image, and a function is selected from the correction coefficient storage unit according to the information on the environment when determining the correction coefficient. the image processing method according to claim 1 5. In an image processing method for converting an input image into an output image for visualizing the input image, color adjustment is performed so that the observer perceives the image as a uniform hue as a visual characteristic of the observer observing the visualized image. The user condition setting means extracts the feature related to the equal hue perception from the result, the correction coefficient determining means determines the correction coefficient using the extracted feature related to the equal hue perception, and the above-mentioned input image is extracted from the input image according to the determined correction coefficient. The color correction processing means performs color conversion to an output image, and the above-mentioned adjustment is performed by an observer adjusting the state such that the saturation of a representative color is changed and perceived as an equal hue. An image processing method characterized by extracting features relating to hue perception . The image processing method according to claim 17 , wherein a common color gamut compression process is performed after performing a correction process depending on an observer according to the correction coefficient. The correction coefficient determining means determines a correction coefficient for color gamut compression processing according to the result of the color adjustment as the correction coefficient, and the color correction processing means includes color gamut compression processing according to the determined correction coefficient. The image processing method according to claim 17 , wherein color processing is performed. The image processing method according to claim 19 , wherein the correction coefficient is determined according to a set color temperature of an image to be visualized. Leave to further store a plurality of correction coefficients in the correction coefficient storage unit, the correction coefficient storage unit and determines the correction coefficient by is selected from the correction coefficient storing Claim 1 2 or claims the image processing method according to any one of clauses 2 0. Furthermore, to obtain information about peripheral stimulus when referring visualized image, either claim 1 2 or claim 2 1, in consideration of the information on the peripheral stimulus and determines the correction factor The image processing method according to claim 1. Run the input image from the input image to a computer in an image processing program for causing a conversion to an output image for visualizing an image processing method according to the computer in any one of claims 1 2 or claim 2 2 An image processing program characterized in that In a storage medium readable computer which stores the image processing program to perform the conversion into an output image for visualizing the input image from the input image into the computer, any one of claims 1 2 or claim 2 2 A storage medium storing an image processing program for causing a computer to execute the image processing method according to claim 1.

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