Abstract: An image display system comprises a display unit which includes regularly arranged red, green and blue pixel elements and which changes a displaying state of the pixel elements to display an image; a pixel data generator which generates pixel data consisting of three items of first pixel element data corresponding to red, green and blue signal levels; a pixel element data generator which converts the pixel data into several items of second pixel element data as a minimum unit data corresponding to the signal levels of respective colors; and a controller which selects any one of a first display mode on the basis of the pixel data outputted from the pixel data generator and a second display mode on the basis of the second pixel element data generated in the pixel element data generator, wherein when selecting the second display mode, the controller sets a pixel number of the pixel data generated in the pixel data generator so as to coincide with a display pixel number of the display unit.

Abstract: An image having a large contrast and excellent visibility to the viewer is displayed on an image display device used in the presence of light. A black-display characteristic specifying means (5A) generates a black-display characteristic specifying data (BD1) indicating the brightness of the external light reflected from the surface of an image display means (3), which is obtained by operating an external-light brightness specifying bar to be displayed on the image display means (3). A black-approximated data calculating means (4A) calculates, based on the black-display characteristic specifying data (BD1), a black-approximated data (R3, G3, B3) related to at least one of luminance, chromaticity and tristimulus values in displaying black with the image display means (3).

Abstract: In a color conversion characteristic determining method for use with an image display device in which image data is converted on a pixel-by-pixel basis, referring to the color conversion characteristic, and the color-converted image is displayed, a color conversion characteristic candidate is set, and color-converted data are predicted by using input image data, and then tristimulus values of the displayed colors are predicted, and the results are evaluated to judge whether the color conversion characteristic satisfies the requirement. It is possible to make the color conversion characteristic to obtain color reproduction closer to the ideal color reproduction according to a standard, and the color conversion characteristic can be determined in a short time.

Abstract: By changing coefficients of second-order and first-order calculation terms relating to respective hues, and first-order calculation terms in the form of comparison-result data relating to respective inter-hue areas, only the target hue or inter-hue area among the six hues of red, blue, green, yellow, cyan, and magenta, and the six inter-hue areas can be varied, without affecting other hues and inter-hue areas. Thus, the six hues and six inter-hue areas can be corrected independently, and the large-capacity memory is not required.

Abstract: Disclosed are a method (and computer system embodying the method) of outputting original image data that was generated relative to a first color space by an output device that converts image data of a second color space to a visually-perceptible analog thereof. Such a method comprises: receiving from a provider, over a communication channel, original image data that was generated according to a first color space; receiving from the provider, over a communication channel along with the image data, tag data representing parameters of the first color space; the output device automatically converting the original image data into the second color space according to the tag data to produce converted image data; and the output device converting the converted image data into a visually-perceptible analog thereof. Alternatively, the output device can monitor the presence of tag data.

Abstract: A process is provided for developing and converting a lookup table (hereinafter called a “LUT”) composed of only characteristic points of the characteristic of a color device and having a volume smaller than that of a multidimensional LUT into a multidimensional LUT by a table development process. Image data converting means uses the multidimensional LUT to convert input image data into output image data. Thus, an effect can be obtained in that a color management apparatus can be operated with only the LUT composed of only characteristic points of the characteristic of the device and having a small volume.

Abstract: A reproducible color gamut compression apparatus includes: a target reproducible color gamut computing unit for computing a target reproducible color gamut; a compression ratio computing unit for computing a compression ratio, based on reproducible color gamuts of display devices and on the target reproducible color gamut; a compression method determination information acquiring unit for acquiring information used to determine a compression method; a compression method determining unit for determining a method of compressing a source reproducible color gamut, based on the compression method determination information; and a reproducible color gamut compressing means for converting the source reproducible color gamut into the target reproducible color gamut, using the determined compression method.

Abstract: A process is provided for developing and converting a lookup table (hereinafter called a “LUT”) composed of only characteristic points of the characteristic of a color device and having a volume smaller than that of a multidimensional LUT into a multidimensional LUT by a table development process. Image data converting means uses the multidimensional LUT to convert input image data into output image data. Thus, an effect can be obtained in that a color management apparatus can be operated with only the LUT composed of only characteristic points of the characteristic of the device and having a small volume.

Abstract: In an image display device for receiving and displaying image data, color converter converts the image data on the basis of conversion characteristics data stored in a conversion characteristics storage. The conversion characteristics designation means including means for designating the chroma of the colors outputs the conversion characteristics designation data, and conversion characteristics setting means calculates the conversion characteristics data on the basis of the conversion characteristics designation data, and sets the conversion characteristics data in the conversion characteristics storage. The color converter comprises a calculation term generator for receiving the first image data, and outputting calculation terms which are effective just for the specific hues; and a matrix calculator performing matrix calculation using the calculation terms effective just for the specific hues. The user can adjust just the chroma of the desired color.

Abstract: In an image display device for receiving and displaying image data, color converter converts the image data on the basis of conversion characteristics data stored in a conversion characteristics storage. The conversion characteristics designation means including means for designating the hue of the colors outputs the conversion characteristics designation data, and conversion characteristics setting means calculates the conversion characteristics data on the basis of the conversion characteristics designation data, and sets the conversion characteristics data in the conversion characteristics storage. The color converter comprises a calculation term generator for receiving the first image data, and outputting calculation terms which are effective just for the specific hues; and a matrix calculator performing matrix calculation using the calculation terms effective just for the specific hues. The user can adjust just the hue of the desired color.

Abstract: Tone calculation for conversion from input image data X to produce converted data Y is performed in accordance with a functional formula including at least two of a first-order term of the input image data X, a second-order term of the input image data X, a third-order term of the input image data X, and a fraction term of the input image data X. In another aspect, color conversion from image data R, G and B to produce printing data C, M and Y by generating complementary color data Ci, Mi and Yi from the image data, determining a minimum value .alpha. and a maximum value .beta. of the complementary color data, generating hue data r, g, b, c, m and y from the complementary color data, the minimum value and the maximum value, generating predetermined matrix coefficients, and determining printing data C, M and Y in accordance with a predetermined matrix calculation using the minimum value, the hue data, and the matrix coefficients.

Abstract: The image processing device converts input image data into converted data. A two way buffer in the image processing device stores reference data generated by a converted data generator under the direction of a controller. The two way buffer is then used to generate converted data in response to received image data. Also, depending upon the input device connected to the image processing device, a selector selects one of a plurality of processing characteristics. The selected processing characteristics are used to vary and set a conversion function for converting the image data to produce the converted data.

Abstract: An image processing method and apparatus for performing tone conversion on input image data X to produce converted data Y set a functional formula including at least two of a first-order term of the input image data X, a third-order term of the input image data X, and a fraction term of the input image data X. Alternatively, the function formula includes at least two of a second-order term of the input image data X, a third-order term of the input image data X, and a fraction term of the input image data X. Then, the converted data Y is output in accordance with the functional formula.

Abstract: An image processing apparatus and method for performing color conversion on first image data of a first format to produce second image of a second format different from the first format. Each of the first and second image data represent a pixel of one of a stationary image and a moving image. The method and apparatus generate complementary color data from the first image data for each pixel of an image, determine a minimum and maximum value of the complementary color data, generate hue data representing a hue of each pixel of the image based on the complementary color data, the minimum value and the maximum value, and generate the second image data based on the hue.

Abstract: A catalyst and a method for catalytically decomposing nitrogen oxides, wherein the catalyst comprises a zeolite having a mole ratio of SiO.sub.2 /Al.sub.2 O.sub.3 of at least 20, and containing (i) copper ions and (ii) (a) transition metal ions other than copper ions, (b) at least one alkaline earth metal ion selected from calcium, strontium and barium ions, (c) yttrium ions, or (a) silver ions.

Abstract: A catalyst and a method for catalytically decomposing nitrogen oxides; the catalyst being composed of a zeolite having a mole ratio of SiO.sub.2 /Al.sub.2 O.sub.3 of at least 20 and containing copper ions and magnesium ions.