Netpbm is a toolkit for conversion of images between a variety of
different formats, as well as to allow a few basic image operations.
Netpbm is based on the widely spread Pbmplus package (release: 10 Dec
91).  On top of that, a lot of improvements and additions have been
made. After the latest release of Pbmplus, a lot of additional filters
have been circulating on the net. The aim of Netpbm was, to collect
these and to turn them into a package. This work has been performed by
a group of programmers all over the world.

anytopnm - attempt to convert an unknown type of image file to a portable anymap
asciitopgm - convert ASCII graphics into a portable graymap
atktopbm - convert Andrew Toolkit raster object to portable bitmap
bioradtopgm - convert a Biorad confocal file into a portable graymap
bmptoppm - convert a BMP file into a portable pixmap
brushtopbm - convert a doodle brush file into a portable bitmap
cmuwmtopbm - convert a CMU window manager bitmap into a portable bitmap
fitstopnm - convert a FITS file into a portable anymap
fstopgm - convert a Usenix FaceSaver(tm) file into a portable graymap
g3topbm - convert a Group 3 fax file into a portable bitmap
gemtopbm - convert a GEM .img file into a portable bitmap
giftopnm - convert a GIF file into a portable anymap
gouldtoppm - convert Gould scanner file into a portable pixmap
hipstopgm - convert a HIPS file into a portable graymap
hpcdtoppm v0.3 - convert a Photo-CD file into a portable pixmap
icontopbm - convert a Sun icon into a portable bitmap
ilbmtoppm - convert an ILBM file into a portable pixmap
imgtoppm - convert an Img-whatnot file into a portable pixmap
lispmtopgm - convert a Lisp Machine bitmap file into pgm format
macptopbm - convert a MacPaint file into a portable bitmap
mgrtopbm - convert a MGR bitmap into a portable bitmap
mtvtoppm - convert output from the MTV or PRT ray tracers into a portable pixmap
pbmclean - flip isolated pixels in portable bitmap
pbmlife - apply Conway's rules of Life to a portable bitmap
pbmmake - create a blank bitmap of a specified size
pbmmask - create a mask bitmap from a regular bitmap
pbmpscale - enlarge a portable bitmap with edge smoothing
pbmreduce - read a portable bitmap and reduce it N times
pbmtext - render text into a bitmap
pbmto10x - convert a portable bitmap into Gemini 10X printer graphics
pbmto4425 - Display PBM images on an AT&T 4425 terminal
pbmtoascii - convert a portable bitmap into ASCII graphics
pbmtoatk - convert portable bitmap to Andrew Toolkit raster object
pbmtobg - convert a portable bitmap into BitGraph graphics
pbmtocmuwm - convert a portable bitmap into a CMU window manager bitmap
pbmtoepsi - convert a portable bitmap into an encapsulated PostScript
pbmtoepson - convert a portable bitmap into Epson printer graphics
pbmtog3 - convert a portable bitmap into a Group 3 fax file
pbmtogem - convert a portable bitmap into a GEM .img file
pbmtogo - convert a portable bitmap into compressed GraphOn graphics
pbmtoicon - convert a portable bitmap into a Sun icon
pbmtolj - convert a portable bitmap into HP LaserJet format
pbmtoln03 - convert protable bitmap to DEC LN03+ Sixel output
pbmtolps - convert portable bitmap to PostScript
pbmtomacp - convert a portable bitmap into a MacPaint file
pbmtomgr - convert a portable bitmap into a MGR bitmap
pbmtopgm - convert portable bitmap to portable graymap by averaging areas
pbmtopi3 - convert a portable bitmap into an Atari Degas .pi3 file 
pbmtopk - convert a portable bitmap into a packed (PK) format font
pbmtoplot - convert a portable bitmap into a Unix plot(5) file
pbmtoptx - convert a portable bitmap into Printronix printer graphics
pbmtox10bm - convert a portable bitmap into an X10 bitmap
pbmtoxbm - convert a portable bitmap into an X11 bitmap
pgmtoybm - convert a portable bitmap into a Bennet Yee "face" file
pbmtozinc - convert a portable bitmap into a Zinc bitmap
pbmupc - create a Universal Product Code bitmap
pcxtoppm - convert a PCX file into a portable pixmap
pgmbentley - Bentleyize a portable graymap
pgmcrater - create cratered terrain by fractal forgery
pgmedge - edge-detect a portable graymap
pgmenhance - edge-enhance a portable graymap
pgmhist - print a histogram of the values in a portable graymap
pgmkernel - generate a convolution kernel
pgmnoise - create a graymap made up of white noise
pgmnorm - normalize the contrast in a portable graymap
pgmoil - turn a portable graymap into an oil painting
pgmramp - generate a grayscale ramp
pgmtexture - calculate textural features on a portable graymap
pgmtofs - convert portable graymap to Usenix FaceSaver(tm) format
pgmtolispm - convert a portable graymap into Lisp Machine format
pgmtopbm - convert a portable graymap into a portable bitmap
pgmtoppm - colorize a portable graymap into a portable pixmap
pi1toppm - convert an Atari Degas .pi1 into a portable pixmap
pi3topbm - convert an Atari Degas .pi3 file into a portable bitmap
picttoppm - convert a Macintosh PICT file into a portable pixmap
pjtoppm - convert an HP PaintJet file to a portable pixmap
pktopbm - convert packed (PK) format font into portable bitmap(s)
pnmalias - antialias a portable anyumap.
pnmarith - perform arithmetic on two portable anymaps
pnmcat - concatenate portable anymaps
pnmcomp - composite two portable anymap files together
pnmconvol - general MxN convolution on a portable anymap
pnmcrop - crop a portable anymap
pnmcut - cut a rectangle out of a portable anymap
pnmdepth - change the maxval in a portable anymap
pnmenlarge - read a portable anymap and enlarge it N times
pnmfile - describe a portable anymap
pnmflip - perform one or more flip operations on a portable anymap
pnmgamma - perform gamma correction on a portable anymap
pnmhistmap - draw a histogram for a PGM or PPM file
pnmindex - build a visual index of a bunch of anymaps
pnminvert - invert a portable anymap
pnmmargin - add a border to a portable anymap
pnmnlfilt - non-linear filters: smooth, alpha trim mean, optimal
pnmnoraw - force a portable anymap into plain format
pnmpad - add borders to portable anymap
pnmpaste - paste a rectangle into a portable anymap
pnmrotate - rotate a portable anymap by some angle
pnmscale - scale a portable anymap
pnmshear - shear a portable anymap by some angle
pnmsmooth - smooth out an image
pnmtile - replicate a portable anymap into a specified size
pnmtoddif - Convert a portable anymap to DDIF format
pnmtofits - convert a portable anymap into FITS format
pnmtops - convert portable anymap to PostScript
pnmtorast - convert a portable pixmap into a Sun rasterfile
pnmtosgi - convert a portable anymap to a SGI image file
pnmtosir - convert a portable anymap into a Solitaire format
pnmtotiff - convert a a portable anymap into a TIFF file
pnmtoxwd - convert a portable anymap into an X11 window dump
ppm3d - convert two portable pixmap into a red/blue 3d glasses pixmap
ppmbrighten - change an images Saturation and Value from an HSV map
ppmchange - change all pixels of one color to another in a portable pixmap
ppmdim - dim a portable pixmap down to total blackness
ppmdist - simplistic grayscale assignment for machine generated, color images
ppmdither - ordered dither for color images
ppmflash - brighten a picture up to complete white-out
ppmforge - fractal forgeries of clouds, planets, and starry skies
ppmhist - print a histogram of a portable pixmap
ppmmake - create a pixmap of a specified size and color
ppmmix - blend together two portable pixmaps
ppmnorm - normalize the contrast in a portable pixmap
ppmntsc - make a portable pixmap look like taken from an American TV
ppmpat - make a pretty pixmap
ppmquant - quantize the colors in a portable pixmap down to a specified number
ppmquantall - run ppmquant on a bunch of files all at once, so they share a common colormap
ppmqvga - 8 plane quantization
ppmrelief - run a Laplacian relief filter on a portable pixmap
ppmshift - shift lines of a portable pixmap left or right by a random amount
ppmspread - displace a portable pixmap's pixels by a random amount
ppmtoacad - convert portable pixmap to AutoCAD database or slide
ppmtobmp - convert a portable pixmap into a BMP file
ppmtogif - convert a portable pixmap into a GIF file
ppmtoicr - convert a portable pixmap into NCSA ICR format 
ppmtoilbm - convert a portable pixmap into an ILBM file
ppmtomap - extract all colors from a portable pixmap
ppmtomitsu - convert a portable pixmap to a Mitsubishi S340-10 file
ppmtopcx - convert a portable pixmap into a PCX file
ppmtopgm - convert a portable pixmap into a portable graymap
ppmtopi1 - convert a portable pixmap into an Atari Degas .pi1 file
ppmtopict - convert a portable pixmap into a Macintosh PICT file
ppmtopj - convert a portable pixmap to an HP PaintJet file
ppmtopjxl - convert a portable pixmap into an HP PaintJet XL PCL file
ppmtopuzz - convert a portable pixmap into an X11 "puzzle" file
ppmtorgb3 - separate a portable pixmap into three portable graymaps
ppmtosixel - convert a portable pixmap into DEC sixel format
ppmtotga - convert portable pixmap into a TrueVision Targa file
ppmtouil - convert a portable pixmap into a Motif UIL icon file
ppmtoxpm - convert a portable pixmap into an X11 pixmap
ppmtoyuv - convert a portable pixmap into an Abekas YUV file
ppmtoyuvsplit - convert a portable pixmap into 3 subsampled raw YUV files
psidtopgm - convert PostScript "image" data into a portable graymap
qrttoppm - convert output from the QRT ray tracer into a portable pixmap
rasttopnm - convert a Sun rasterfile into a portable anymap
rawtopgm - convert raw grayscale bytes into a portable graymap
rawtoppm - convert raw RGB bytes into a portable pixmap
rgb3toppm - combine three portable graymaps into one portable pixmap
sgitopnm - convert a SGI image file to a portable anymap
sirtopnm - convert a Solitaire file into a portable anymap
sldtoppm - convert an AutoCAD slide file into a portable pixmap
spctoppm - convert an Atari compressed Spectrum file into a portable pixmap
spottopgm - convert SPOT satellite images to Portable Greymap format
sputoppm - convert an Atari uncompressed Spectrum file into a portable pixmap
tgatoppm - convert TrueVision Targa file into a portable pixmap
tifftopnm - convert a TIFF file into a portable anymap
xbmtopbm - convert an X11 or X10 bitmap into a portable bitmap
ximtoppm - convert an Xim file into a portable pixmap
xpmtoppm - convert an X11 pixmap into a portable pixmap
xvminitoppm - convert a XV "thumbnail" picture to PPM
xwdtopnm - convert a X11 or X10 window dump file into a portable anymap
ybmtopbm - convert a Bennet Yee "face" file into a portable bitmap
yuvplittoppm - convert a Y- an U- and a V-file into a portable pixmap.
yuvtoppm - convert Abekas YUV bytes into a portable pixmap
zeisstopnm - convert a Zeiss confocal file into a portable anymap