Page 1 of 1

PNG display problem

Posted: Thu Jun 01, 2006 6:22 pm
by 7creature
Hi!

I've encoutered this strange (well, I guess you all there probably know what is it and how to solve it :wink: ) problem with PNGs.

When I convert 32bit images to PNG, they are not visible at all in web browser and in Photoshop. Thumbnails in XnView are blank but in View mode image is displayed without problems. But when I check "Compose with alpha (32bits)" then again the image is blank even in View mode (and color count shows just 1).

So I am asking - how is it possible to create 32bit functional PNG with XnView? Is it possible, isn't it?

Sample image is here:
Image

Posted: Thu Jun 01, 2006 8:16 pm
by 7creature
Hmm, in TweakPNG's internal Viewer when I check 'Use Custom Background Color' image isn't visible (or I should say it is *under* that background it seems). Otherwise it is displaying without problems (without background).

Edit: Hmmm, those pictures don't include an area which should be transparent - but somehow the whole image is set to be transparent (at least it seems to be the case). Really strange, isn't it? :?:

Edit: Hmm, I guess it was quite stupid idea to convert 32bit BMP to PNG :? I should probably reduce it to 24bit beforehand... Hmm, maybe there could be such option in XnView - i.e. when saving as PNG to be able to convert image to 24bit (when coverting images which are not transparent at all).

So problem solved :P Well, I have to say, it was quite interesting :)

P.S. I really love XnView - superb program already and still getting better and better :mrgreen: Thank you very very much Pierre-e :P

Re: PNG display problem

Posted: Fri Jun 02, 2006 7:34 am
by xnview
7creature wrote: When I convert 32bit images to PNG, they are not visible at all in web browser and in Photoshop. Thumbnails in XnView are blank but in View mode image is displayed without problems. But when I check "Compose with alpha (32bits)" then again the image is blank even in View mode (and color count shows just 1).

So I am asking - how is it possible to create 32bit functional PNG with XnView? Is it possible, isn't it?
Perhaps the alpha channel is black???

Posted: Sun Jun 04, 2006 3:32 pm
by 7creature
Yes, alpha channel was set to 0 for every pixel, so image was completely transparent :) Just removing alpha channel before conversion to PNG solves the problem.