Abstract: This invention provides a display control apparatus and control method, which allow the operator to easily identify the correspondence between the patch icons and their color difference values. To accomplish this, the display control method of this invention includes an icon displaying step of displaying a plurality of color difference values computed based on a first data group and second data group associated with spectral reflectance characteristics as a plurality of patch icons. The display control method includes a numeric value displaying step of displaying the color difference values represented by the patch icons in one of a first display format that displays, as numeric values, the color difference values within display regions of the patch icons, and a second display format that displays, as numeric values, the color difference values above display regions of a plurality of patch icons.

Abstract: This invention provides a display apparatus, control method, and control program, which display hue differences and color difference values of respective patches as lists, and display the hue direction of the hue difference of each individual patch on a chromaticity diagram in an easy-to-understand manner. To accomplish this, a display method of this invention includes a specifying step of specifying a color determined by a hue difference calculated from first and second values associated with spectral reflectance characteristics, and a display step of displaying the color specified in the specifying step as a graphical object. The specified color is specified as a representative color that indicates a hue on a chromaticity diagram to which the hue difference biases.

Abstract: There is provided a method of creating a color chart for color evaluation used in color evaluation, including: an obtaining step of obtaining standard color chart data corresponding to a standard color chart including a plurality of patches; a display step of displaying an evaluation target image on a display screen; a setting step of setting an area in the evaluation target image, which is used to create a color chart for color evaluation; a computing step of computing color element data which represent color features of an image within the set area based on image data of the set area; and a creating step of creating the color chart for color evaluation by extracting patch data corresponding to the computed color element data from the standard color chart data.

Abstract: Upon observing homogeneity in page image by the human eye, a permissible level associated with color reproduction with respect to an identical color signal changes depending on the distance from an interest point. Since the conventional homogeneity in page image evaluation scheme doesn't take the above characteristics into consideration, the correlation between a finished image and the evaluation result cannot be exploited fully. Hence, image data, which forms an image with identical density within a range to be evaluated in one page, is output to a printer to measure reflection characteristics of the image at points on output of the printer. One point is set as a reference point, and distances between the reference point and the remaining points, and differences of the reflection characteristic between the reference point and the remaining points are calculated. The image quality within the range is evaluated based on the distances and differences.

Abstract: Color reproducibility needs to be evaluated in consideration of the influence of homogeneity in page image. Hence, a first chart is formed from an image of a uniform density of a region to be evaluated, and data associated with the spectral reflectances of plural points on the first chart are input. Based on the data obtained from the first chart, color differences between a predetermined point and other points on the first chart are calculated. When the calculated color differences fall within a permissible range of heterogeneity of colors in the region, a second chart is formed from an image corresponding to a color target, and data associated with the spectral reflectances of plural points on the second chart are input. Color differences are calculated from the data obtained from the second chart and data associated with the spectral reflectance of the color target.

Abstract: An image density discrimination chart is used to discriminate a density of a test image printed by an image forming apparatus. The chart includes an exposing portion for exposing the test image when the chart is overlaid relative to a printed recording material, a first comparison image having an upper limit level of a latitude, permitted by the image forming apparatus, for image density of the test image, and a second comparison image having a lower limit level of a latitude, permitted by the image forming apparatus, for image density of the test image.

Abstract: An image processing apparatus for forming an image using at least three color materials includes a first generation device for generating a plurality of patches of secondary colors composed of color materials of two different colors; a first measurement device for measuring the patches; a first correction characteristic calculation device for calculating gradation-correction characteristics corresponding to each of the two color materials; a second generation device for generating a group of patches in accordance with an image signal for the two different color materials and an image signal for color materials other than the two color materials by using an image signal corrected on the basis of the gradation-correction characteristics; a second measurement device for measuring patches generated by the second generation device; and a second correction characteristic calculation device for calculating gradation-correction characteristics of image signals for color materials other than the two different color ma

Abstract: In an image forming apparatus which forms a color image by superposing cyan, magenta, yellow and black toners on a recording medium, a circuit to limit image signals is provided immediately before a gamma correction circuit which corrects an output characteristic inherent in the apparatus so that the sum total of the signal levels of the image signals of the respective colors does not exceeds a predetermined value. Thus, even if a user arbitrarily sets color profile data for color management, a toner spread amount can be controlled not to exceed the predetermined value.

Abstract: There is provided a method of creating a color chart for color evaluation used in color evaluation, including: an obtaining step of obtaining standard color chart data corresponding to a standard color chart including a plurality of patches; a display step of displaying an evaluation target image on a display screen; a setting step of setting an area in the evaluation target image, which is used to create a color chart for color evaluation; a computing step of computing color element data which represent color features of an image within the set area based on image data of the set area; and a creating step of creating the color chart for color evaluation by extracting patch data corresponding to the computed color element data from the standard color chart data.

Abstract: This invention provides a display apparatus, control method, and control program, which display hue differences and color difference values of respective patches as lists, and display the hue direction of the hue difference of each individual patch on a chromaticity diagram in an easy-to-understand manner. To accomplish this, a display method of this invention includes a specifying step of specifying a color determined by a hue difference calculated from first and second values associated with spectral reflectance characteristics, and a display step of displaying the color specified in the specifying step as a graphical object. The specified color is specified as a representative color that indicates a hue on a chromaticity diagram to which the hue difference biases.

Abstract: This invention provides a display control apparatus and control method, which allow the operator to easily identify the correspondence between the patch icons and their color difference values. To accomplish this, the display control method of this invention includes an icon displaying step of displaying a plurality of color difference values computed based on a first data group and second data group associated with spectral reflectance characteristics as a plurality of patch icons. The display control method includes a numeric value displaying step of displaying the color difference values represented by the patch icons in one of a first display format that displays, as numeric values, the color difference values within display regions of the patch icons, and a second display format that displays, as numeric values, the color difference values above display regions of a plurality of patch icons.

Abstract: Color reproducibility needs to be evaluated in consideration of the influence of homogeneity in page image. Hence, a first chart is formed from an image of a uniform density of a region to be evaluated, and data associated with the spectral reflectances of plural points on the first chart are input. Based on the data obtained from the first chart, color differences between a predetermined point and other points on the first chart are calculated. When the calculated color differences fall within a permissible range of heterogeneity of colors in the region, a second chart is formed from an image corresponding to a color target, and data associated with the spectral reflectances of plural points on the second chart are input. Color differences are calculated from the data obtained from the second chart and data associated with the spectral reflectance of the color target.

Abstract: Upon observing homogeneity in page image by the human eye, a permissible level associated with color reproduction with respect to an identical color signal changes depending on the distance from an interest point. Since the conventional homogeneity in page image evaluation scheme doesn't take the above characteristics into consideration, the correlation between a finished image and the evaluation result cannot be exploited fully. Hence, image data, which forms an image with identical density within a range to be evaluated in one page, is output to a printer to measure reflection characteristics of the image at points on output of the printer. One point is set as a reference point, and distances between the reference point and the remaining points, and differences of the reflection characteristic between the reference point and the remaining points are calculated. The image quality within the range is evaluated based on the distances and differences.

Abstract: Image data supplied to an image forming apparatus are converted into image data linearly correlated with the image density, and the image ratio is calculated by dividing the number of pixels in which the toner is deposited during image formation based on the thus-converted image, with a value obtained by multiplying the total pixel number corresponding to the size of the print medium with the number of gradation levels per pixel. Then the toner amount consumed in the image formation based on the entered image data is determined by multiplying the image ratio, the size of the print medium to be used and the toner amount consumed per unit area in a solid image formation.

Abstract: This invention relates to a method of setting anti-forgery information addition level while taking an apparatus individual difference into consideration. The method is employed by a data processing system including: an image processing apparatus 100 for processing an image; and a maintenance apparatus 120, connected with the image processing apparatus through a network 110, for setting a processing function of the image processing apparatus 100. The maintenance apparatus 120 determines an anti-forgery information addition level depending on an individual difference of apparatuses, such as an exhaustion level of the image processing apparatus 100. The addition level determined by the maintenance apparatus 120 is transmitted to the image processing apparatus 100. The image processing apparatus 100 adds anti-forgery information to an inputted image at the addition level transmitted by the maintenance apparatus 120.

Abstract: An image density discrimination chart for discrimination of a density of an image, usable with an image forming apparatus, the image density discriminating charl includes an exposure portion for being overlapped on an image density discrimination pattern printed on a recording material, and exposing an image density discrimination pattern; and a plurality of comparison patterns which have densities different from each other, disposed aroud the exposure portion, which is to be compared with the image density discrimination pattern exposed through the exposure portion

Abstract: An image can be outputted with a high sharpness without deteriorating a resolution. In order to output an image of a high picture quality while suppressing the occurrence of a moire, an exposure amount is modulated in accordance with pixel density information of the image divided into pixels of a predetermined size by an exposure amount modulating unit in a light scanning unit, thereby expressing an image dark/light state. In this case, in a highlight density region in which a pixel density is equal to or less than ⅓ of the maximum image density, the density data of two adjoining pixels is modulated by one pixel and the other pixel is not recorded. In a density region in which the image density lies within a range from ⅓ to ½ of the maximum image density, a part of the density data of one of the two adjoining pixels is transposed to the other pixel.

Abstract: An image processing apparatus for forming an image using at least three color materials includes a first generation device for generating a plurality of patches of secondary colors composed of color materials of two different colors; a first measurement device for measuring the patches; a first correction characteristic calculation device for calculating gradation-correction characteristics corresponding to each of the two color materials; a second generation device for generating a group of patches in accordance with an image signal for the two different color materials and an image signal for color materials other than the two color materials by using an image signal corrected on the basis of the gradation-correction characteristics; a second measurement device for measuring patches generated by the second generation device; and a second correction characteristic calculation device for calculating gradation-correction characteristics of image signals for color materials other than the two different color ma

Abstract: In an image forming apparatus which forms a color image by superposing cyan, magenta, yellow and black toners on a recording medium, a circuit to limit image signals is provided immediately before a gamma correction circuit which corrects an output characteristic inherent in the apparatus so that the sum total of the signal levels of the image signals of the respective colors does not exceeds a predetermined value. Thus, even if a user arbitrarily sets color profile data for color management, a toner spread amount can be controlled not to exceed the predetermined value.

Abstract: When pixels in a two-dimensional matrix are divided into lines A and B in the column (or row) direction (sub-scanning direction) and two neighboring pixels in the row (or column) direction are subjected to gradation correction respectively using characteristic curves for lines A and B, the characteristic curve for line B unpreferably has a stepwise characteristic portion having a step when it is stored in an LUT, due to quantization errors unique to digital values. Hence, the characteristic curve for line A is set to be decreased by the amount corresponding to the step.