--pix-filter-level=<0-100>

The pix-filter-level option interacts with the threshold-level and shape-filter-level options to determine the balance between foreground and background. A value of 0 indicates that the maximum number of pixels should be placed into the foreground, and a value of 100 indicates that the maximum number of pixels should be placed in the background. A value of 25 is the optimum setting for most 300 dpi documents. The pixel filter parameter corresponds to a penalty added each time there is a transition from foreground to background, weighted by the difference in luminance between the foreground and background (if two contiguous pixel belong to the same layer, there is no penalty). Reasons why it would decide not to segment foreground are that there are too many such transitions, or that the difference in luminance is not large enough.

Examples that work well with the 25 default value are:


However, the segmentation can sometimes be improved by lowering this value and giving more room for the threshold color to fluctuate.