ppm2rgba
rgba2ppm
rgbaadd
rgbaaddB
rgbaautocrop
rgbadither
rgbafade
rgbamerge
rgbamergeB
rgbaquant
rgbascale
rgbascaleB
rgbascaleF
rgbasub
rgbasubB
rgbatrans
the RGBA32 manual and style guide
Last updated January 23, 1997
general usage and notes
RGBA32 can be used in conjunction with pbmplus and other UNIX utilities such as xpaint, gimp and XV to create and manipulate high quality images. RGBA32 adds alpha-channel capabilities to this party.RGBA32 can be used on the command line or in scripts. These examples demostrate using RGBA32 for scaling, mixing, filtering, illumination, fading, translucence rendering, cropping, chromakeying (masking), antialiasing and colormap quantization.
filter reference
- ppm2rgba is used to convert PPM/PBM/PGM format files to RGBA32 format.
- rgba2ppm is used to convert RGBA32 files into raw PPM format.
- rgbaautocrop cuts excess solid colored borders and unused space from around images.
- rgbafade fades images (increasing or decreasing transparency) from edge to edge or corner to corner.
- rgbamerge, rgbamergeB, rgbaadd, rgbaaddB, rgbasub and rgbasubB are used to mix two images together according to their transparency levels.
- rgbaquant and rgbadither reduce the number of colors used in an RGBA image.
- rgbascale, rgbascaleB and rgbascaleF are used to reduce and enlarge images while antialiasing.
- rgbatrans sets one or all colors in an image to transparent or translucent.
troubleshooting
