Color imaging system and process with high-speed rendering

A system for processing images includes an image file subsystem providing a source signal representing an input image; a color transformation subsystem coupled to the image file subsystem and accepting as input the source signal and producing a target signal therefrom, and an image forming subsystem coupled to the color transformation subsystem and forming a physical manifestation of the input image in response to the target signal, the color transformation subsystem being configured to establish a memory "cube" area representative of possible source signals, to define a sub-cube portion of the memory area as representative of the source signal; to determine possible target signals corresponding to the sub-cube portion; and to determine the target signal responsive to the possible target signals. If interpolation is found to be accurate for a mini-cube portion of the sub-cube, truncation or interpolation are used to derive the target signal; otherwise, the target signal is determined directly.