counter 38 increments as each of the 256 segment lengths are reached the dynamic range compression slope is based on the local area histogram compression term upper minus lower histogram breakpoints 24 23 the dynamic range compression slope includes 256 segments wherein each segment represents an output pixel value the length of each segment determines the number of input pixel values to be mapped to an output pixel value the angle of the slope is established by the segment length and determines the amount of the dynamic range compression the upper 4 bits of the compression term determine the basic integer segment length there are 3048 possible compression slopes 15 are integer slopes i e 1 1 2 1 3 1 15 1 between each integer slope 255 non integer slopes are possible the lower 8 bits of the compression term determine the number and position of each lengthened segment and establishes the fractional portion of the slope fig7 a and 7b show two typical histograms and the resulting dynamic range projections wherein the detailed areas show the individual segments that make up the slope the slope generator 36 uses the rising edges on each bit of the 8 bit output dynamic range counter 38 that occur at 255 unique times by combining the output dynamic range counter 38 rising edges with the lower 8 bits of the compression term the required long segments can be evenly.