#20 How to fight watermark GIF file

[JOY]

How to fight watermark GIF file?
I use:
gm composite -gravity SouthEast -dissolve 50 -quality 88.0 logo.png 1.gif 2.gif

But I found that only the first frame of the watermark.

[Glenn Randers-Pehrson]

Your commandline seems to work for me. The syntax for "composite" is

gm composite [options] changefile basefile outputfile

so you'd only get one output (2.gif) which is the change file (logo.png) dissolved onto the lower left corner of the input (1.gif).

In this context, the "-quality 88.0" option is ignored (the GIF encoder does not use it), so you should omit it (but if you were writing JPEG, then "-quality 88" (not 88.0) would be useful).

If you were expecting your command to work like "mogrify" (overlaying logo.png on both 1.gif and 2.gif), you could do this:

for x in 1.gif 2.gif
do
gm composite -gravity SouthEast -dissolve 50 logo.png $x $x
done

[JOY]

Thank you for your help.
If I want each frame of 2.gif has a watermark, what should I do.

[Glenn Randers-Pehrson]

To watermark each frame of an animated GIF, try

gm convert -coalesce +adjoin 1.gif frame%04d.gif
for x in frame*.gif
do
  gm composite -gravity SouthEast -dissolve 50 logo.png $x $x
done
gm convert -deconstruct frame*.gif 2.gif

This splits your 1.gif into individual files frame0000.gif,
frame0001.gif, etc., watermarks each with logo.png, and then
reassembles them into a new animation (2.gif). I don't know
if it's the most efficient method, but it does work for me.