Canon Kabushiki Kaisha

Satoshi Takayama

Nobuatsu Sasanuma

Tomohisa Itagaki

Toshio Saishoji

Masami Tomita

Miyoko Hayashi

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.

Color difference display control apparatus, color difference display control method, and control program

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.

Display apparatus, display method, and control program

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.

Method of creating color chart for color evaluation, and information processing apparatus thereof

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.

Method and apparatus for calculating distances and reflection differences between measurement points on printed matter to evaluate image quality

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.

Growing community of inventors

Chofu, Japan

Satoshi Takayama