1. A method for forming an output halftone image having a plurality of output halftone image pixels from an input image having a plurality of input image pixels, the method comprising processing the input image pixels with a halftoning process that incorporates a hard dot stability constraint, the process forcing a determination to produce a dot for each of M output halftone image pixels following an output halftone image pixel dot that would otherwise be isolated, where M&gE;1.