On 12/21/2015 11:41 AM, pickupthestix16 wrote:

Hello All!

This is my first post and I'm a bit familiar with GIMP but am still kind of a newbie to the program. I particularly got it so that I could create my own signature for a forum that I participate on regularly.

I recently hit a road block that I can't seem to get around and I'm not sure if it's possible at all. I wanted to make an animated Gif image and I wanted the original gif to be transparent. I didn't know any other way to do this, so I simply separated all 54 frames and edited each photo myself, and then re-formatted them back into a gif. I then opened as layers each of the frames.

So far so good. However, see below...

I used the "Lighten Only" effect on the rest of the images on the signature, so I wanted to keep the gif that way too. This required me to go through each of the 54 frames and select "Lighten Only". At first, I ran into this problem http://imgur.com/l5fiKq7. Even though each frame said "replace", it didn't seem to actually replace the previous frame.

The GIF file format does not have any provision for layer modes. It doesn't even have 'real' transparency - each pixel can be either completely opaque or completely transparent, but nothing in between.

So, although the file you are editing in the GIMP displays the results you intend when setting layers to Lighten Only mode, every frame / layer of an exported GIF file will be saved in 'normal' mode and effects created by stacking layers in Lighten Only mode will be lost.

Then I downloaded an animation script called "Animastack". I put [bg] on the background frame and [fg] on the foreground frame and then "processed animastack tags" and it grouped together all frames with the foreground and background so I had 54 separate groups. When I did the "playback" though, it worked! IT FINALLY WORKED! i was so happy; I had spent so long trying to get it to work.

Then I tried to export the file as a gif and ran into the "indexed or grayscale" issue. Is there ANY WAY to export this without changing the colors? Anything other than "gif" that I could export to that would have a similar effect?

I don't think indexed vs. grayscale is the problem. All GIF images are indexed; that's way the GIF file format works. Every color that appears in a GIF image is specified in a palette stored in the image file, with an "index" that enables programs that display GIF images to fetch the right color from the palette to every pixel. A grayscale image exported as a GIF will be an indexed file, where every color in the index is a shade of gray.

Whatever effect you are getting by using a Lighten Only mode can be exported to a GIF, but you will need to use a stack of "normal mode" layers to make that happen.

First get one frame of the animation to show up in your main image window (the canvas), looking like you want it to, by using layer modes or any other tool or technique. Then in the Layers dialogue do "New from visible." This will give you a new layer that is a 'normal' mode snapshot, duplicating what you see on the canvas. Layers made this way can then be stacked up and saved as an animation.

Making the first frame of your animation transparent will 'just work'. Replacing one layer rather then adding layers as the animation plays is an option you can select while saving your image as an animated GIF.

You can also adjust the delay between frame changes in your animation any way you want, by hand - for instance to briefly stop it on one frame before continuing with the others. Just re-open the animated GIF in the GIMP and look at the names of the layers: The duration of the frame is part of the layer name. Editing this, then saving the file as an animated GIF, results in an animation with whatever frame change delays (or speed-ups) you specified.

:o)