I'd be happy to give you a definitive answer, but – as mentioned before – I never completely figured out what impact these parameters have, how they “interact” with each other, and why they are available for PNG format only.wolfgangbeyer wrote:In XnView transparency is not edited but only displayed, so far I understand. So I don’t understand the option Tools » Options » General » Read/Write » Read » PNG » Parameters » Compose ...
What I have to offer is the configuration I finally settled on after going through a fair amount of trial & error work:
- General » Read/Write » Read » PNG
[ ] Compose image with transparency
[ ] Compose image with alpha (32bits)
- View » View
- Auto Image Size [Fit image to window, large only]
- Background colour [R128/G128/B128]
- [x] Use transparent index (<=8bits) or alpha channel
Yes, that's my interpretation of Use transparent index (<=8bits) or alpha channel too.wolfgangbeyer wrote:Or does off means to ignore the transparent/alpha maske and display the hidden colors in the RGB channels, which are actually intended not to be visible due to the transparency? Than off as default seems nonsense for me.
BTW: Just recently the possibility to switch transparency off turned out to be crucial in identifying a problem.
These options have been discussed in many threads. I'd like to bring two of them in particular to your attention, where you will find some comments from Pierre: