Single bit-map block truncation coding of color images

A color-image data compression technique based on block truncation coding (BTC) is described. BTC is first implemented to encode a weighted trichromatic image. The bit map generated is then used to compress each of the R, G, and B signals separately, removing the intercolor correlations. The weighted trichromatic signal is generated by properly weighting R, G, and B signals so that the reconstructed R, G, and B signals have minimum mean square error (MSE). Another approach using a bit-wise majority rule on the R, G, and B BTC bit maps is also discussed. The algorithm preserves the spatial details in the image content and has low computational complexity. An 8:1 compression can be achieved