GNOME Bugzilla – Bug 62847
png saves bad with background color
Last modified: 2004-04-01 23:44:57 UTC
Netscape 4.77 displays the image at the given URL with less colors when it is saved as indexed png with _background_color_. A similar but smaller image (bp.gif) is displayed correctly. Dunno wether this is a Netscape or GIMP bug. bad image with 'save background color' parameter: http://rainbow.hn.org/bernhard/bpu-background.png good image without 'save background color' parameter: http://rainbow.hn.org/bernhard/bpu-background.png source image: http://rainbow.hn.org/bernhard/bpu.gif small image (with background color): http://rainbow.hn.org/bernhard/bp.png http://rainbow.hn.org/bernhard/bp.gif Please don't download the images more than necessary from my server. Maybe you can copy them to your site and update the URLs. Thank you.
Created attachment 5894 [details] badly displayed image
Created attachment 5895 [details] bpu.gif, source file that I converted to bpu-background.png
I attached bpu-background.png http://bugzilla.gnome.org/showattachment.cgi?attach_id=5894 and bpu.gif http://bugzilla.gnome.org/showattachment.cgi?attach_id=5895 and deleted bpu-background.png from my server. I'm not sure, maybe the colors are just displayed wrongly and are not less. Bernhard
This is not a GIMP bug, but a known problem with your browser. Support for transparent PNGs is broken in all versions of Netscape 4.x that I know of. Try to load your images in Mozilla, they display correctly. Here's a good page to test your browsers PNG capabilities: http://entropymine.com/jason/testbed/pngtrans/ If all you need is one level of transparency (like what you have with GIF), try to set the GIMP's background color to white before saving. This makes the created PNG display correctly in Netscape 4.x.
Minor correction: This is indeed a bug in Netscape 4.x and not in the Gimp, but in order to allow the PNG image to display (almost) correctly in Netscape 4.x, the background color must be set to black, not white. NN4 replaces all black pixels by the background color if the background color was specified in the PNG file. Another (obvious) solution is to uncheck the "save background color" box in the options of the PNG plug-in.
The URL field has been removed from bugzilla.gnome.org. This URL was in the old URL field, and is being added as a comment so that the data is not lost. Please email bugmaster@gnome.org if you have any questions. URL: http://rainbow.hn.org/bernhard/bpu-background.png