Spatiochromatic multiplexing: a color image representation for digital processing and compression

Abstract

Digital color images are represented by 3 color values for each picture element (pixel). The most common types of color coordinates for capture and display are RGB, but they are transformed into YUV (or other luminance-chrominance type of space) for image processing and compression. The conventional wisdom being that while luminance data are processed at full spatial and temporal resolution, chrominance information can be considerably subsampled without significant losses in perceived image quality. Also, the 3-fold complexity of RGB 3- channel processing can be usually reduced to 2-fold: one channel for luminance and another for chrominance. We have been studying the advantages of a different image representation, one suggested by biological systems. It requires only one color value at each pixel location, reducing the total data load to one third, and it can be processed, compressed and transmitted with the simplicity of a monochrome image (i.e., one-channel complexity) by adequate handling of entropy increments. At the receiver, this representation can be decoded into a full color picture of the same perceived quality and resolution as a picture represented and processed in conventional ways. Technical developments related to this representation have been presented here before; and specific technical advantages have been registered. This technology eliminates the burden of front-end color space transformation, and removes the complexity of separate computations for chromatic and achromatic processing. Specific applications comprise four areas: (1) Simplification of processing, storage, compression, and transmission of digital color images. (2) Economical full-color upgrading of black and white image capturing systems. (3) Increase up to 4x of spatial resolution in high-quality digital image capturing systems currently designed for triplane color capture (three separate CCDs). (4) Extension of the three areas above to dynamic sequences (digital video and motion pictures). [truncated]