PNG looses transparency

[glennrp]

Yes, confirmed that the bug is still there with the autolevel gradient problem in the Q16 build (but not in Q8). The cropped-rose looks OK now in both Q8 and Q16.

[glennrp]

The -taint sets a flag, yes. One thing that flag does is to cause the PNG encoder to do a SyncImage() before encoding the PNG, which is not appropriate for 16-bit images. I added another test in the PNG encoder to skip the SyncImage when ( image->depth > 8 ) in the SVN head. That seems to fix the problem. Maybe SyncImage() itself should be modified to return without action when the depth is 16 or more.

[anthony]

The original problem has now been fixed in IM v6.6.6-3.

lets hope that all the transparency bugs have now been squashed.

Any new problems should be in a new topic, so I will now lock this topic.