PDA

View Full Version : lossless image with GIMP?



MikeCyber
April 10th, 2013, 07:11 AM
I remember a good while ago that manipulating png images resulted in a lower quality image than doing the same in Photoshop 7. Foremost the pixels within a transparent region got worse. I had numbers there which were hardly readable anymore.
I've heard that in 2.8 there were improvements in that direction but wonder if I should try again?
Thanks

SeijiSensei
April 10th, 2013, 05:00 PM
When you export to png, GIMP offers a variety of quality options. I've found setting compression to zero or one makes a big difference when it comes to text.

BcRich
April 10th, 2013, 10:52 PM
I remember a good while ago that manipulating png images resulted in a lower quality image than doing the same in Photoshop 7. Foremost the pixels within a transparent region got worse. I had numbers there which were hardly readable anymore.
I've heard that in 2.8 there were improvements in that direction but wonder if I should try again?
Thanks

Hi MikeCyber
I do recall (vaguely) the issue you are referring to, which I encountered quite a few years ago. To be honest, I have not considered this problem since at least gimp 2.6. I can't say for certain that it no longer exists as I don't have photoshop to compare results with, but I currently do not notice any particular image degradation (other than what would be expected) from using transform tools on multi-layer images with transparency. The issue might have related to poor anti-aliasing in older versions of the GIMP, this might be one of the reasons why rendering of the canvas was ported to CAIRO from version 2.6.