On 2/18/20 2:10 PM, this is what Brian Gregory wrote:
On 17/02/2020 21:23, Big Al wrote:
optipng doesn't change the image quality any?Â*Â* I've never used it,
just installed it on my system.Â* I ran a test and some images were cut
in half.Â* My eye doesn't see any quality diff.

Further to my first reply. "Cut in half" is rare and suggests that the
original program that created them didn't choose the compression
parameters at all well, or maybe chose them aiming for highest possible
execution speed, or tested only on a photo where the more intensive
compression often makes only a little difference.

I have to agree with the poor choice on the first file creation. The
whole folder of 184 images that one must have been the best fix, but the
others were like .3% and some as high as 4%. Overall not worth the
work. I think Paul eluded to that too.

Thanks. Fun exercise though.
Al