Description:

This is a plugin for GIMP versions 2.0.x. It allows you to convert
images into RGB normal maps for use in per-pixel lighting
applications. The goal is to completely clone NVIDIA's Photoshop
plugin, with a few new useful features.

Features:
- Filters. These include the filters found in the NVIDIA plugin (4
sample, 3x3, 5x5, 7x7 and 9x9) with the addition of a 3x3 Sobel and
Prewitt edge detection filter (yields the best results IMO).
- Post-filtering normal scaling
- Wrap mode. This allows the filters to wrap around the image. Useful
for creating normalmaps from a tiling bumpmap.
- Height source. Use an average of the RGB components or the alpha
channel as the height source in the generation of the normals.
- Alpha result. For RGBA images, the alpha channel can either remain
unchanged, have the height used to generate the normal written to it,
or be replaced by either 0 or 1.
- Conversion options including "Normalize only" for renormalizing
bumpmaps.
- DU/DV map creation (8 and 16 bit, signed or unsigned)
- Dynamic 2D preview in the interactive dialog.
- Dynamic 3D preview window unsing OpenGL to view the normalmap
applied to a lit primitive