From: Jim Clark [mailto:[EMAIL PROTECTED]
Sent: Thursday, April 14, 2005 5:05 PM
To: Kalle Ounapuu
Subject: RE: [Gimp-user] png compression
Things get odder and odder.
I need to put 10 screen shots on a web page and was hoping to shave 100K from the final page.
So I took one of my images and indexed it.
Before index: 27004
After index: 30705.
It got larger? I downloaded and installed a png crusher and ran it against both files:
27004 after crush became: 19419 or a 28% reduction
30705 did not change--all the crushed versions were larger.
So now I have 4 images which all look about the same, ranging in size from 19419 to 30705. Quite a hit or miss process. One would think indexing and crushing would yield the smallest image, but it did not.
Crushers shouldn't give you larger filesize... by default all of them have the overwrite_if_bigger function set to off.
Another PNG tool that is handy: TweakPNG
This displays all the PNG chunks being used, and allows you to see what is changing in a PNG file exactly.