optipng

Optimizer for PNG files

OptiPNG is a PNG optimizer that recompresses image files to a smaller size, without losing any information. This program also converts external formats (BMP, GIF, PNM; TIFF support is coming up) to optimized PNG, and performs PNG integrity checks and corrections. The idea has been inspired from pngcrush, and is explained in detail in the PNG-Tech article "A guide to PNG optimization". The implementation is carried forward in OptiPNG, which offers a faster execution per trial, and a wider search space.