GIMP Plugin Registry

Easily map colours from a source colour to a target colour. Very effective for matching skin tones across images or between people.

Relatively quick (but not earth shattering). It doesn't work with grayscale or indexed images. Has preview, works with selections and layers, etc. Very, easy to use, and quite useful for portraits or recolouring graphics.

A demonstration: Lenna's face is mapped to the colour of the feather on her hat. This was done by selecting a colour from her face, then selecting a colour from the feather.  read more »

Slices and joins scriptfu is useful when you want to split one image 'file' into smaller 'files', and to recombine it successively. One single image 'file' can be split into unlimited number of files. Image-slice script save on the file imagename.rcm all the data for the reconstruction.
For more information ..

Example

Merge visible using the active layer transparency to create a mask, visible layers below are discarded.

This can be useful in 3d applications to preserve texture maps that belong in the alpha channel by using the bottom layer's mask to hold the information.

Appears in /Image/Merge Visible with Layer Mask & Alpha of the Image window.

A set of plugins and scripts for astronomical image processing

Not intended for scientific image processing, due to gimp's 8bit depth restriction (for "pretty pictures" only).

News:

31.07.2008: gimp-plugin-astronomy-0.6
29.06.2008: gimp-plugin-astronomy-0.5
25.03.2008: gimp-plugin-astronomy-0.4  read more »

Plugins:

• Align layers using center of brightness or 2D (fourier) cross correlation or gauss fit, subpixel-resolution, with de-rotation!