Last time We were talked about jpegoptim and jpegtran. Today we will talk about OptiPNG. 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, and TIFF) to optimized PNG, and performs PNG integrity checks and corrections.
Check standard packages:
# apt-get install optipng
How to use
Single file optimization
# optipng test.png
In order to optimize all the files in the images directory:
# find public / images / -iname * .png -print0 | xargs -0 optipng -o7