MEDIAN FILTERING OF AMBTC IMAGES FOR IMPROVED IMAGE COMPRESSION.

One-dimensional median filtering is applied to a new form of block truncation coding called absolute-moment block truncation coding (AMBTC). The AMBTC algorithm is far simpler to implement than the original block-truncation-coding algorithm. Results show that the application of one-dimensional median filtering increases the data compression rate while the average mean-square error of a block of 4 multiplied by 4 pixels is only slightly greater than that of a block-truncation-coded image.