URT(1)

NAME
urt - overview of the Utah Raster Toolkit

SYNOPSIS
applymap    Apply color map to image data.
avg4    Simple 2x2 downsizing filter.
crop    Crop image.
cubitorle    Convert Cubicomp format to RLE.
dvirle    Typeset TeX ".dvi" files as RLE images.
fant    Image scale/rotate with anti-aliasing.
get4d    Display on SGI Iris/4D display.
get_orion    Display on "Orion" display.
getap    Display on Apollo.
getbob    Display under HP window system.
getcx3d    Display RLE on Chromatics CX3D.
getfb    Display using BRL generic fb library.
getgmr    Display on Grinnell GMR-27 frame buffer.
getiris    Display on SGI 2400/3000 w/o window manager.
getmac    Display on Mac under MPW.
getmex    Display on SGI under the window manager.
getqcr    Display on Matrix QCR camera.
getren    Display on HP SRX.
getsun    Display using SunTools.
getx10    Display on X10 display.
getx11    Display using X11.
giftorle    Convert GIF files to RLE.
graytorle    Convert separate rrr ggg bbb files to RLE.
mcut    Median cut color quantization.
mergechan    Merge colors from multiple images.
painttorle    Convert MacPaint to RLE.
pgmtorle    Convert PBMPLUS pgm format to RLE.
ppmtorle    Convert PBMPLUS ppm format to RLE.
pyrmask    Generate "pyramid" filter mask.
rastorle    Convert Sun Raster to RLE.
rawtorle    Convert various raw formats to RLE.
read98721    Read the screen of an HP 98721 "Renaissance" to an RLE file.
repos    Reposition an image.
rlatorle    Convert Wavefront RLA format to RLE.
rleClock    Draws a clock face.
rleaddcom    Add comments to an RLE file.
rleaddeof    Add an EOF code to an RLE file.
rlebg    Generate a "background".
rlebox    Find bounding box of an image.
rlecomp    Image composition.
rledither    Floyd-Steinberg dither an image to a given colormap.
rleflip    Flip an image or rotate it 90.
rlehdr    Print info about an RLE file.
rlehisto    Make a histogram of an image.
rleldmap    Load a new colormap into a file.
rlemandl    Make a Mandelbrot image.
rlenoise    Add noise to an image.
rlepatch    Patch smaller images on a big one.
rleprint    Print all pixel values in image.
rlequant    Variance based color quantization.
rlescale    Generate a "gray scale".
rleselect    Select images from an RLE file.
rlesetbg    Set the background color of an image file.
rleskel    Skeleton tool.  Programming example.
rlespiff    Simple contrast enhancement.
rlesplice    Splice two images horizontally or vertically.
rlesplit    Split concatenated images into files.
rlestereo    Combine two images into a "red-green" stereo pair.
rleswap    Swap or select color channels.
rletoabA60    Convert RLE to Abekas A60 format.
rletoabA62    Convert to Abekas A62 format.
rletoascii    Make a line-printer/CRT version of an RLE image.
rletogif    Convert RLE images to GIF format.
rletogray    Convert RLE to separate rrr ggg bbb files.
rletopaint    Convert RLE to MacPaint.
rletoppm    Convert RLE to PBMPLUS ppm format.
rletops    Convert RLE to (B&W) PostScript.
rletorast    Convert RLE to Sun Raster.
rletoraw    Convert RLE to rgbrgb raw format.
rletorla    Convert RLE to Wavefront RLA format.
rletotiff    Convert RLE to TIFF 24 bit format.
rlezoom    Scale image by sub- or super-sampling.
smush    Generic filtering.
targatorle    Convert TARGA to RLE.
tifftorle    Convert TIFF 24 bit images to RLE.
to8    24 to 8 bit ordered dither color conversion.
tobw    Color→B&W conversion.
unexp    Convert "exp" format to normal colors.
unslice    Paste together "slices" into a full image.
wasatchrle    Convert Wasatch paint system to RLE.

DESCRIPTION
The Utah Raster Toolkit is a collection of programs and C routines for dealing with raster images commonly encountered in computer graphics. A device and system independent image format stores images and information about them. Called the RLE(5) format, it uses run length encoding to reduce storage space for most images. The programs (tools) currently included in the toolkit are listed above, together with a short description of each one. Most of the tools read one or more input RLE files and produce an output RLE file. Some generate RLE files from other information, and some read RLE files and produce output of a different form. An input file is almost always specified by mentioning its name on the command line. Some commands, usually those which take an indefinite number of non-file arguments (e.g., rleaddcom) require a -i flag to introduce the input file name. If the input file name is absent the tool will usually read from the standard input. An input file name of "-" also signals that the input should be taken from the standard input. On Unix systems, there are two other specially treated file name forms. A file name starting with the character '|' will be passed to sh(1) to run as a command. The output from the command will be read by the tool. A file whose name ends in ".Z" (and which does not begin with a '|') will be decompressed by the compress(1) program. Both of these options supply input to the tool through a pipe. Consequently, certain programs (those that must read their input twice) cannot take advantage of these features. This is noted in the manual pages for the affected commands. An output file is almost always specified using the option -o outfile. If the option is missing, or if outfile is "-", then the output will be written to the standard output. On Unix systems, the special file name forms above may also be used for output files. File names starting with '|' are taken as a command to which the tool output will be sent. If the file name ends in ".Z", then compress will be used to produce a compressed output file. Several images may be concatenated together into a single file, and most of the tools will properly process all the images. Those that will not are noted in their respective man pages. Picture comments. Images stored in RLE form may have attached comments. There are some comments that are interpreted, created or manipulated by certain of the tools. In the list below, a word enclosed in <> is a place-holder for a value. The <> do not appear in the actual comment.

image_gamma=<float number>
    Images are sometimes computed with a particular ``gamma'' value -- that is, the pixel values in the image are related to the actual intensity by a power law, pixel_value=intensity^image_gamma. Some of the display programs, and the buildmap(3) function will look for this comment and automatically build a "compensation table" to transform the pixel values back to true intensity values.

display_gamma=<float number>
    The display_gamma is just 1/image_gamma. That is, it is the ``gamma'' of the display for which the image was computed. If an image_gamma comment is not present, but a display_gamma is, the displayed image will be gamma corrected as above. The to8 program produces a display_gamma comment.

colormap_length=<integer>
    The length of the colormap stored in the RLE header must be a power of two. However, the number of useful entries in the colormap may be smaller than this. This comment can be used to tell some of the display programs (getx11, in particular) how many of the colormap entries are used. The assumption is that entries 0 - colormap_length-1 are used. This comment is produced by mcut, rlequant, and rledither.

image_title=<string>
    This comment is used by getx11 to set the window title. If present, the comment is used instead of the file name. (No other programs currently pay attention to this comment.) The comments IMAGE_TITLE, title, and TITLE are also recognized, in that order. No programs produce this comment.

HISTORY=<string>
    All toolkit programs (with the exception of rleaddcom) create or add to a HISTORY comment. Each tool appends a line to this comment that contains its command line arguments and the time it was run. Thus, the image contains a history of all the things that were done to it. No programs interpret this comment.

exponential_data
    This comment should be present in a file stored in ``exponential'' form. See unexp(1) and float_to_exp(3) for more information. The unexp program expects to see this comment.

SEE ALSO
compress(1), sh(1), RLE(5).

AUTHOR
Many people contributed to the Utah Raster Toolkit. This manual page was written by Spencer W. Thomas, University of Michigan.