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Image Utilities and Converters

There are lots of file formats in the world. The odds that the file format you have is the file format want is slim, so file format converters abound.

Converters

convert -- A good general purpose converter ImageMagick's convert program. The syntax is simple:
convert filename.have filename.want
Convert will look at the extensions and attempt the conversion. Chances of success are good. For details, consult the man page.
Portable Bitmap Toolkit -- This is a collection of programs which convert a wide variety of file formats to and from the various portable bitmap formats (.pbm, .pgm, .ppm, and .pnm). It is a little more laborious, but it gives you lots of control, has lots of related utilities, and is very dependable. One particularly useful program is anytopnm, which attempt to determine the file format and convert to .pnm format. For full details, consult the man page for pbm.
xv -- The program xv can also be used to convert file types. xv isn't designed as a converter, but if you aren't doing anything strange, it works fine.
OmniImage -- On the NeXT, one occasionally runs into trouble because NeXT images have 12 bit color instead of 24 bit color. OmniImage, like xv, is not primarily designed for conversion, but it will often work to get an image into some portable format, if you want to do something esoteric to it.
gifconvert -- On the Macintosh, use the program GIFConverter. It is located in the "Graphics Apps" folder under the apple menu.

Utilities

There are also a lot of miscellaneous utilities. Rather than trying to remember them, remember that man -k pattern will give a list of all man pages whose headers contain the pattern. However, to get an idea of what's out there, here is a list.

WWW

img2gif -- Convert an image into transparent, interlaced GIF for the WWW <
giftrans -- giftrans is the underlying C program that the shell script img2gif uses. At the Center, there is never any reason to use it. It is listed here for people thinking of installing resources on their home systems.

Printing

imgtek -- Print an image to the Tektronix color printer
pan -- print a color image on the Panasonic printer

Size and Shape

imgcomp -- composites multiple images together
imgfit -- fit an image, possibly including a label, into a given area
imgtile -- tile many small images into a few large ones
pbmmake -- create a blank bitmap of a specified size
pbmmask -- create a mask bitmap from a regular bitmap
pbmpaste -- paste a rectangle into a portable bitmap
pnmcat -- concatenate portable anymaps
pnmcrop -- crop all like-colored borders off portable anymap
pnmcut -- select a rectangular region from portable anymap
pnmenlarge -- enlarge a portable anymap N times
pbmreduce -- read a portable bitmap and reduce it N times
pnmindex -- script to build a visual index of a bunch of anymaps
pnmmargin -- script to add a margin to a portable anymap
pnmrotate -- rotate a portable anymap pnmscale -- scale a portable anymap
pnmshear -- shear a portable anymap
pnmflip -- perform one or more flip operations on a portable anymap
pnmtile -- replicate a portable anymap into a specified size
fant -- perform simple spatial transforms on an image

Image Processing

pnmgamma -- perform gamma correction on a portable anymap
pnminvert -- invert a portable anymap
pgmedge -- edge-detect a portable graymap
pgmenhance -- edge-enhance a portable graymap
pgmhist -- print a histogram of the values in a portable graymap
pgmnorm -- normalize contrast in a portable graymap
pgmoil -- turn a portable graymap into an oil painting
pgmbentley -- Bentleyize a portable graymap
pgmramp -- generate a grayscale ramp
pgmtexture -- calculate textural features on a portable graymap
ppmdither -- ordered dither for color images
ppmquant -- quantize colors down to a specified number
ppmquantall -- script to run ppmquant on a set of pixmaps
ppmrelief -- run a Laplacian Relief filter on a portable pixmap
pnmconvol -- general MxN convolution on a portable anyma
pnmsmooth -- script that uses pnmconvol to smooth a anymap
rlenoise -- Add random noise to an RLE image
rlequant -- variance based color quantization for RLE images
rlescale -- produce RLE gray scale images.
rleselect -- Select images from an RLE file.
rlespiff -- Use simple contrast enhancement to "spiff up" an RLE image.

Truely Miscellaneous

pbmlife -- apply Conway's rules of Life to a portable bitmap
pbmtext -- render text into a bitmap
pbmtoascii -- convert a portable bitmap into ASCII graphics
pgmcrater -- create cratered terrain by fractal forgery
ppmforge -- fractal forgeries of clouds, planets, and starry skies
ppmpat -- create a pretty pixmap
pnmfile -- describe a portable anymap
pnmnoraw -- force a portable anymap into ASCII format
pbmupc -- create a Universal Product Code bitmap
sgifade -- generate a fade between two image files.
pyrmask -- Blend two images together using Gaussian pyramids.
rlebox -- print bounding box for image in an RLE file.
rlemandl -- Compute images of the Mandelbrot set.

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Created: Fri Sep 8 11:39:00 1995 --- Last modified: Jun 18 1996