Ubuntu – How to create an animated gif from still images (preferably with the command line)

Try opening them with The Gimp; I believe it will open animated gifs with one layer per frame.

You say you don't want to dump all frames to files on a directory, but I'll tell you how to do it anyway :) install either ImageMagick or graphicsmagick, then:

for ImageMagick:

convert animation.gif target.png

for graphicsmagick:

gm convert animation.gif target.png

it'll write frames to target0.png,target1.png,... and so on. You can then enter the directory and run eog, it'll show you all the frames on the same application. When you no longer need the frames, just rm target*.png.

I assume you're using http://www.imagemagick.org/. The -dispose command describes what is to be done with the frame after its delay (when the next frame is loaded). Info here: http://www.imagemagick.org/Usage/anim_basics/#dispose

-dispose previous

try:

convert -delay 5 -dispose previous -loop 0 Frame_7_00000*.png" animated.gif