Adapted from the README: the FBM collection provides a complete package for
manipulating and converting images, including 24-bit RGB, 8-bit color, 8-bit
grayscale, and 1-bit bitmaps.  This is a partial list of the commands:
	fbclean	  Flip isolated pixels (clean image)
	fbconv	  Arbitrary convolutions
	fbedge	  Compute derivative image (edge detection)
	fbext	  Extract region, resize, change aspect ratio
	fbgamma	  Gamma correct grayscale or color image for display
	fbhalf	  Halftone grayscale image (Blue noise, Floyd-Steinberg, etc)
	fbhist	  Compute histogram
	fbmask	  Set region to gray value
	fbmedian  Median filter 3x3 regions
	fbnorm	  Normalize image intensity / increase contrast
	fbquant	  Color quantization (24-bit to 8..256 colors) Mod. Heckbert
	fbrot	  Rotate 90, 180, or 270 degrees
	fbthin	  Thin 1-bit images
	fbsharp	  Sharpen (edge enhancement) by digital Laplacian
	idiff	  (and udiff) convert raw byte stream into byte difference
	pbmtitle  Add a title to a PBM file
The FBM utilities handle these image formats:  native FBM, UseNet Facesaver, raw
(e.g. Amiga Digiview), Targa, Sun rasterfile with 32 byte header, Aldus TIFF,
Poskanzer PBM format for 1-bit files, CompuServe GIF, JPEG JFIF, Utah RLE, Amiga
IFF (except HAM mode), PC PaintBrush PCX, and Bennet Yee's 1-bit Face files.
Amiga HAM, Diablo graphics, and PostScript output is available.