The Gimp default png export already has compression maxed out at value 9
Small reduction in file size is possible if the 'extras' exif etc are unticked.
Otherwise can you give more details. Are you trying to hit a particular file size. It might be possible to adjust an image somehow (drastically reduce the number of colours for example) to get a smaller size.
Small reduction in file size is possible if the 'extras' exif etc are unticked.
Otherwise can you give more details. Are you trying to hit a particular file size. It might be possible to adjust an image somehow (drastically reduce the number of colours for example) to get a smaller size.