07-19-2017, 09:45 AM
Not an easy one.
What was a green mask in a video, after mangled into a gif is no longer plain green.
Worth a look at what indexed color means.
Each pixel is assigned a color from a colormap maximum number of colors 256. You can see this in Gimp Windows -> Dockable Dialogues -> Colormap and it is worth checking.
![[Image: VwhdCuF.jpg]](http://i.imgur.com/VwhdCuF.jpg)
That block of green variants is the 'background' for that image. The one circled, index 201 is the majority. Worth noting the value RGB 28,208,0
You can edit those one at a time and make it more uniform, about 40 to do. That might allow a 'color-to-alpha' plugin to work on all layers. I did try this with not so good results. Tends to make the foreground semi-transparent from those remaining 'green-ish' values. You need something with some tolerance settings.
Start with the usual Filters -> Animation -> Unoptimise and Image -> Mode -> RGB
I ended up using a plugin G'mic There are versions for Mac, but probably not work with your version. http://gmic.eu/download.shtml You might have to change versions, The Partha MacGimp version comes with lots of pre-installed extras.
This is the gmic filter Colors -> Select-replace
screenshot: http://i.imgur.com/raHEmBD.jpg
The important bits
(1) The two colors are the same (does not look like it but they are RGB 28,208,0) (2) output Rejected colors (3) Input/Output All and New Image (4) With the gui at full screen to minimise green speckles I got the settings shown. Play with the tolerance maybe 35 to 45
Apply that and you get a mainly transparent background. Used Ofnuts Interleave-layers twice, once for the background and a second time to overlay that bottom right corner.
screenshot: http://i.imgur.com/PJXGYWm.jpg
If you get gmic working, try it. My try http://www.mediafire.com/file/eg424h7fpp...back.xcfgz 25 MB
Otherwise, back to editing one layer at a time, only a 100 of them
What was a green mask in a video, after mangled into a gif is no longer plain green.
Worth a look at what indexed color means.
Each pixel is assigned a color from a colormap maximum number of colors 256. You can see this in Gimp Windows -> Dockable Dialogues -> Colormap and it is worth checking.
That block of green variants is the 'background' for that image. The one circled, index 201 is the majority. Worth noting the value RGB 28,208,0
You can edit those one at a time and make it more uniform, about 40 to do. That might allow a 'color-to-alpha' plugin to work on all layers. I did try this with not so good results. Tends to make the foreground semi-transparent from those remaining 'green-ish' values. You need something with some tolerance settings.
Start with the usual Filters -> Animation -> Unoptimise and Image -> Mode -> RGB
I ended up using a plugin G'mic There are versions for Mac, but probably not work with your version. http://gmic.eu/download.shtml You might have to change versions, The Partha MacGimp version comes with lots of pre-installed extras.
This is the gmic filter Colors -> Select-replace
screenshot: http://i.imgur.com/raHEmBD.jpg
The important bits
(1) The two colors are the same (does not look like it but they are RGB 28,208,0) (2) output Rejected colors (3) Input/Output All and New Image (4) With the gui at full screen to minimise green speckles I got the settings shown. Play with the tolerance maybe 35 to 45
Apply that and you get a mainly transparent background. Used Ofnuts Interleave-layers twice, once for the background and a second time to overlay that bottom right corner.
screenshot: http://i.imgur.com/PJXGYWm.jpg
If you get gmic working, try it. My try http://www.mediafire.com/file/eg424h7fpp...back.xcfgz 25 MB
Otherwise, back to editing one layer at a time, only a 100 of them