Ordered dither image rendering with non-linear luminance distribution palette

An apparatus for reproducing color images at a lower color resolution, comprising:

• a first palette comprising a plurality of palette colors;
• a memory for storing a color image as an array of pixels, the pixels being associated with color values in the first palette;
• a second palette having a lower color resolution than the first palette and comprising a plurality of palette colors located at the intersections of three sets of planes, each set of planes being perpendicular to the other sets, a first of the three sets being perpendicular to a luminance axis between black and white in a color gamut;
• a processor for reading the first palette color values associated with the pixel of the stored image from the memory and for ordered dithering the first palette color values to associate palette colors in the second palette with the pixels;
• and
• an output device for reproducing the color image in a visually perceptible form with each pixel of the color image associated with a palette color in the second palette.

A method of approximating a color image using a lower color resolution, comprising:

• selecting a mapping color for a pixel in the image;
• and
• reproducing the image with the pixel having the mapping color,
• the step of selecting comprising ordered dithering a first, high resolution color associated with the pixel to a second color in a reduced resolution palette, the reduced resolution palette comprising a plurality of palette colors located at intersections of three sets of planes within a color gamut, each set of planes being perpendicular to the other sets, a first of the three sets being perpendicular to a luminance axis between black and white in a color gamut.