i'm sorry if this has been brought up before. i've searched and found several topics concerning around this but none really solved my problem, so i thought i should open a new thread after all.
i have an image with indexed colour of which 161 are unique colours. i am editing it in photoshop. it also has a transparent colour.
when i open the psd in irfanview, the transparency is replaced with white. when i save it as gif, the transparency again turns into white. opening the same gif in photoshop will show the transparency fine though. when i save the psd as png, the background in irfan is no longer white but black. i'm presuming that's because it interprets transparency correctly now? (is there any way to enable a checkerboard for transparency like in photoshop?)
i've noticed in photoshop, you cannot change between the 1-9 levels that irfan offers for png compression. (what are the differences here anyway? png is lossless, right? so what's the difference?)
therefore, i wanted to save the photoshop png as an irfan png with compression set to 9 in order to save filesize. (every kb counts for me in this case)
it comes up with a dialog to select the transparent colour. something i don't understand. doesn't it already interpret transparency correctly? why must i reassign it now? in the dialog it shows the transparent colour as black. of course i cannot key this out as my image contains regular black colour in places.
thanks a lot for your support.