Linotype-hell Ag

Wilhelm Dichter

Eggert Jung

A method and system for color transformation of a color variation in an original image into a new color variation in a transformed image of the original image based on a representative color in a target image, the color image workstation is provided having a color computer and a video monitor. The original image and the target image are input into the color computer. A plurality of color samples are picked at points on the target image by use of the video monitor. A statistical analysis is employed to obtain the representative color of the target image. A plurality of color samples are picked at points on the original image also by use of the video monitor. A statistical analysis is employed to obtain a representative color of the original image. By use of the representative color of the original image and the color variation of the original image, and also by use of the representative color of the target image, image points of the original image are transformed to the transformed image.

Color transformation system based on target color image

Original CMYK printing colors of an original image are corrected, and then the corrected printing colors are converted by color computer to RGB video signals for display on a color video display. The desired corrections are defined in terms of HSL (hue, saturation, luminance) changes. The original CMY printing colors are transformed to the corrected or new CMY printing colors by use of the HSL changes without a color space translation. The HSL changes are directly applied to the original CMY printing colors to arrive at the new CMY printing colors. The transformation comprises using a gray line representing an absence of color and changing luminance within the original CMYK printing color space and executing the HSL changes with respect to the gray line. The HSL changes are clamped within the color space so that no new CMYK printing colors result which are unprintable outside the color space.

HSL corrections in CMY color space

A method for defining a three dimensional neighborhood in a CMY color space. A CMY color space is provided having a gray line therein. The neighborhood is defined by defining boundaries thereof based on at least one correction H, S, L range with respect to the gray line. Changes within the neighborhood may be assigned weighting based on HSL positions of color points therein. With the invention, the hue, saturation, and luminance neighborhoods of a selected CMY color are determined directly from the original CMY image and CMY colors with respect to the gray line.

HSL neighborhoods in CMY color space

A method for defining a new value of K (black) corresponding with a change in CMY components. Original CMYK printing colors are provided. The original CMY printing colors are corrected to create new CMY printing colors. A value of a smallest one of the original CMY colors is sensed. A value of a smallest one of the new CMY colors is sensed. By use of each of these smallest values, the original K printing color value is modified to create a recalculated K printing color value. The recalculated black value corrects for distortion of original gray balance.

Growing community of inventors

Tewksbury, MA, United States of America

Wilhelm Dichter