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Name

rlespiff - Use simple contrast enhancement to "spiff up" an image.

Synopsis

rlespiff [ -b blacklevel ] [ -s ] [ -t threshold ] [ -w whitelevel ] [ -o outfile ] [ infile ]

Description

Rlespiff "spiffs up" an image by stretching the contrast range so that the darkest pixel maps to black and the lightest to white. If the -s flag is given, the color channels will be treated separately. This will likely cause some drastic color shifts.

Options

-b blacklevel
The darkest input pixel will map to this pixel value in the output image. The default is 0.
-s
If specified, each color channel will be mapped separately.
-t threshold
This argument controls the number of samples of a pixel value that should be considered insignificant (and will therefore be ignored). It is specified in pixels/million. A threshold of 4 applied to a 512x512 image would mean that any value that existed at only one pixel would be ignored. The default value is 10.
-w whitelevel
The lightest input pixel will map to this pixel value in the output image. The default is 255.
-o outfile
If specified, the output will be written to this file. If outfile is "-", or if it is not specified, the output will be written to the standard output stream.
infile
The input will be read from this file. If infile is "-" or is not specified, the input will be read from the standard input stream.

See Also

urt(1) , RLE(5) .

Author

Spencer W. Thomas


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