GNOME Bugzilla – Bug 145090
Saving an image saves alpha channel instead of picture data
Last modified: 2004-12-22 21:47:04 UTC
Description of Problem: When saving a picture loaded previously that contains an alpha channel (a .psd for instance), the alpha channel is selected by default. Subsequent saving as PNG gives a (not very descriptive) error message and apparently saves the alpha channel. This bug was reported in Red Hat Bugzilla for Fedora Core 2 as https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=125946 Steps to reproduce the problem: 1. Load a .psd file (or perhaps another one with an alpha channel) 2. Save as .png Actual Results: Saved image is black (or not, depending on the alpha channel). Expected Results: Saves complete image, eventually warning user about formats which don't support alpha channels. How often does this happen? Every time. Additional Information: Workaround: Select background (or other layer) in layers dialog.
This bug report misses the point. The save routine is doing the right thing and it tells the user what's happening. If there's a problem at all then it's the PSD plug-in that selects the channel on load. The question is if the channel is marked as the active item in the PSD file. In that case the behaviour would be completely correct. Otherwise the plug-in should probably be changed to select the topmost layer. We will need a copy of the PSD file and information on whether the channel was the selected element in PS (or GIMP) when this file was saved.
Note also that it's not the alpha channel that is saved. It's an auxilary channel that represents a saved selection. There's no way to save the alpha channel only.
Created attachment 29080 [details] PSD example file Photoshop file that exhibits the problem.
The attached file is the one that was attached to the Fedora bug report.
Well, the important question here is if the channel has been active when the file has been created.
This report is waiting for feedback from the bug reporter. Please respond to the question specified in comment #5.
According to a friend with Photoshop 6 on MacOS X, yes it (the attachment in this bug) does have an active auxilary alpha channel. I'm the original reporter of the bug in Red Hat's bugzilla.
The behaviour is not at all surprising then. IMO the plug-in is doing the right thing. I suggest to close as NOTABUG.
I don't see what's unclear in the message that pops up. Closing as NOTABUG.