Abstract: A method for converting digital chrominance signals of a cartesian color coordinate system into digital color signals and saturation signals of a polar color coordinate system and including a transformation circuit for the transformation from cartesian to polar coordinates.

Abstract: An apparatus and a method for the recognition of colors on a colored image illuminated with a light source of a known spectrum composition, wherein the intensities of three primary colors are measured opto-electronically as color components, which represent the spatial co-ordinates of the color locations in a color space. Prior to color recognition the color components of at least one characteristic test point in each color or color region, which is to be recognized, are measured and noted. The test color components represent the corresponding test color locations in the color space. An identification symbol is assigned to each color component triplet of the test points and noted too.

Abstract: A process for the identification of a predetermined plurality of colors on the surface of an object which is scanned by electrical-optical means to produce measured signals substantially representing the colors red, green, and blue coordinates, the plurality of colors defining color-regions, and defining color-identification-regions, wherein the boundaries of the identification-regions are simulated electronically through threshold-value circuits for each of the coordinates, the output signals of which are transferred to coincidence circuits, which indicate the presence of one of the plurality of colors when the coordinates of the color signals lie within the color-identification-region.