Method and apparatus to compress multi-spectral images to a single color image for display

Abstract

A method and apparatus enhance visible contrast within an acquired image for display. The contrast enhancement utilizes all N bands of an original N-band spectral image to produce an M-dimensional enhanced image for display. The method creates an enhanced image from an original image in which the visible contrast in the original image is improved. The original image includes pixels, each pixel having N spectral intensities. The display or printer device which must display the relevant information may be limited to a number of bands M which is smaller than N. Maximum contrast of objects is obtained by emphasizing differences in the N-dimensional pixels by as large differences as possible within the dynamic range of the M-band display space. When M=N=3, this means moving pixels in the display space to utilize the full color palette available on a color monitor or printer. When N>M, a mapping from N space to M space must also be accomplished. In the methods of this patent, the mapping process and the spreading process are accomplished in the same algorithms. Clustering of the raw pixel data is usually used to reduce the computational requirements of the spreading step. Finally, in a creating step, an enhanced image is produced based on the N spectral intensities of each pixel and the N to M mapping developed by the algorithms.