Legacy ImageMagick Discussions Archive

Hello - this is my first post here so firstly - thanks for the incredibly useful software!

I'm having an issue with gif transparency...which I am hoping someone can confirm as a bug or user error (I am assuming the first as previous versions of imagemagick seemed to behave differently)....

Previously (eg with ImageMagick 6.4.0) when converting from pngs to gifs eg or manipulating gifs eg: would yield a gif with suitable transparency. But using the latest fedora 14 binary release (ImageMagick 6.6.4-1 2010-10-05 Q16) yields a gif with an opaque (white) background. I cannot seem to find a recipie to output a gif with any transparency.....

example
input png
output of convert right.png right.gif:

Bug or user error? If a bug - is there a workaround?

Thanks in advance

There certainally seems to be a bug.

The GIF loses transparency when I do... But converting to MIFF and displaying shows the MIFF still has transparency. Doing the same though MIFF however does NOT fix the problem The MIFF shows a transparent background, but the GIF does not!

So whatever is the problem is still present in the MIFF intermediate file format.
As that format has a text based header for ALL image meta data it much be one of the following...

id=ImageMagick version=1.0
class=DirectClass colors=0 matte=True
columns=16 rows=16 depth=8
colorspace=RGB
compression=Zip quality=0
units=PixelsPerCentimeter
resolution=35.43x35.43
page=16x16+0+0
date:create={2010-11-15T13:56:57+10:00}
date:modify={2010-11-15T13:56:57+10:00}
Software={www.inkscape.org}

As you can see transparency is enabled 'matte=True', But I can not see anything else that could be causing the save to GIF to fail. Everything about the header appears right!

Trying a different tack... using 'txt' image to remove all meta data! I still get a GIF without transparency!
And yet the 'IM Enumerated Text Image' file clearly shows pixels with transparency.


Basically I can prettywell be assured that the GIF save for this image and just the image data, is causing it to 'loose transparency. No meta-data is causing the problem.


This is definitely a BUG! but it is only involving image data, not meta-data.

We can reproduce the problem you posted and have a patch in ImageMagick 6.6.5-9 available by sometime tomorrow. Thanks.