07-27-2017, 07:55 AM
Not very complicated but still many pitfalls and hurdles:
1) your snow animation is "optimized", which means that each frame/layer is only the difference with the previous one. You can't work with that directly, use Filters>Animation>Unoptimize to recover one full image per frame
2) Your snow animation being a GIF, it works in a reduced-color mode (color-indexed) and many tools don't work on that mode. You have to put yoru image in full color mode: Image>Mode>RGB
3) To make the layers transparent, you use Colors>Color-to-Alpha on each layer to remove the black. 40 layers. I wrote myself a quick script. Still doable by hand (I'll have a coffee while you do this :
)(*)
4) To insert the animation snow on your banner you have to make 40 copies of the banner (40 layers), and merge one frame of you animation over each copy. I have a script for this: called interleave-layers. However this script requires that the background image (your banner) and the animation have exactly the same image size (otherwise it would ask you where you want the animation to be...). So some further preparation is necessary.
5) Your banner in 202 px high, the snow is 280px so you crop te snow image to 202px. Using the Crop tool(
), in the Tool options, select Fixed->Height, and enter "202" in the size field. Choose the part of the animation to keep.
6) Then we have to widen the snow animation to 1004px to fit the banner. Image>Canvas size, increase the width to 1004. At the bottom of the dialog, you can position the layers in the new canvas by dragging them. I shifted them to the right, so that they are more where the cat looks than on the cat itself. Also, select Resize layers: all layers (this extends your layers with transparency to make them cover the whole canvas).
7) I assume that you have successfully installed the "interleave-layers" script.
8) File>Open and open the banner image
9) Select again the snow image. Image>Interleave layers>Interleave single layer (sprite mode). In the "layer selector, choose the banner image. Keep the defaults for the rest. A new image is created, this is your animation. You can use Filter>Animation>Playback to test it.
10) To save it: File>Export and give a .GIF extension. Tick the Export as animation box.
11) You can also save a smaller file by using Filter>Animation>Optimize (for GIF) before exporting.
My results: https://www.dropbox.com/sh/sincyue22cyxz...SyhIa?dl=0
(*) Slightly faster: Set the bucket-fill too to "Color-erase" mode, set the foreground color to black, and bucket fill
each layer in turn. Even faster, grab the XCF in the shared folder above.
1) your snow animation is "optimized", which means that each frame/layer is only the difference with the previous one. You can't work with that directly, use Filters>Animation>Unoptimize to recover one full image per frame
2) Your snow animation being a GIF, it works in a reduced-color mode (color-indexed) and many tools don't work on that mode. You have to put yoru image in full color mode: Image>Mode>RGB
3) To make the layers transparent, you use Colors>Color-to-Alpha on each layer to remove the black. 40 layers. I wrote myself a quick script. Still doable by hand (I'll have a coffee while you do this :
)(*)4) To insert the animation snow on your banner you have to make 40 copies of the banner (40 layers), and merge one frame of you animation over each copy. I have a script for this: called interleave-layers. However this script requires that the background image (your banner) and the animation have exactly the same image size (otherwise it would ask you where you want the animation to be...). So some further preparation is necessary.
5) Your banner in 202 px high, the snow is 280px so you crop te snow image to 202px. Using the Crop tool(
), in the Tool options, select Fixed->Height, and enter "202" in the size field. Choose the part of the animation to keep.6) Then we have to widen the snow animation to 1004px to fit the banner. Image>Canvas size, increase the width to 1004. At the bottom of the dialog, you can position the layers in the new canvas by dragging them. I shifted them to the right, so that they are more where the cat looks than on the cat itself. Also, select Resize layers: all layers (this extends your layers with transparency to make them cover the whole canvas).
7) I assume that you have successfully installed the "interleave-layers" script.
8) File>Open and open the banner image
9) Select again the snow image. Image>Interleave layers>Interleave single layer (sprite mode). In the "layer selector, choose the banner image. Keep the defaults for the rest. A new image is created, this is your animation. You can use Filter>Animation>Playback to test it.
10) To save it: File>Export and give a .GIF extension. Tick the Export as animation box.
11) You can also save a smaller file by using Filter>Animation>Optimize (for GIF) before exporting.
My results: https://www.dropbox.com/sh/sincyue22cyxz...SyhIa?dl=0
(*) Slightly faster: Set the bucket-fill too to "Color-erase" mode, set the foreground color to black, and bucket fill
each layer in turn. Even faster, grab the XCF in the shared folder above.