Two-Dimensional Luminance Compression
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
This article describes a two dimensional luminance compression technique for compressing a captured image of a discrete color document. A discrete color document is one having luminance and chrominance values which are intended to be constant throughout well-defined areas. Most business documents fall in this category. The compression technique operates on captured data after that data has been filtered and thresholded to remove unintended variations in luminance or chrominance values. The original data is preferably stored in memory in logical lines with each logical line consisting of a series of paired values. One value in each pair is the luminance (Y) of the run. The other value is the pel position (P) at the end of the run.