- define-structure pbm raw? bitmaprecord
- define-structure pgm raw? maxval greyrecord
- define-structure ppm raw? maxval red green bluerecord
- pnm? mprocedure
Three image formats are supported. PBMs are binary images, PGMs are greyscale and PPMs are tri-plane (nominally RGB) images. All planes are stored as scheme matrices. Together all of these formats are called PNM. This is a standard format that many tools (such browser and ImageMagick) can read and write. PNMs can be serialized as either raw packed binaries or ascii text files. Note that we are unable to read or write raw PBMs.