A method for adjusting dot-gain for a halftone binary bitmap file comprises inputting a halftone binary bitmap file consisting of binary pixels (400) to an asymmetric digital filter (500). The binary pixels are filtered with the asymmetric digital filter and generates multi-level pixels (506). The multi-level pixel are compared to a preset level (408) and generates a binary pixel output (410). The binary pixel output is collected and forms an adjusted halftone binary bitmap file (270).