Manual: gamma4scanimage

gamma4scanimage(1)				SANE Scanner Access Now Easy				  gamma4scanimage(1)

NAME
       gamma4scanimage - create a gamma table for scanimage

SYNOPSIS
       gamma4scanimage gamma [shadow [highlight [maxin [maxout]]]]

DESCRIPTION
       The  tool gamma4scanimage creates a gamma table in the format expected by scanimage. You can define a gamma, a shadow
       and a highlight value. You also can specify the size (maxin) and maximum output value (maxout) of the gamma table.

       gamma is a floating point value, neutral value being 1.0. If the value is larger than 1.0 then the image is brighter.

       shadow defines the minimum input value that is necessary to create an output value larger than zero.  shadow  has  to
       be in the range [0..maxin].  Its default value is 0.

       highlight  defines  the	maximum input value that produces an output value smaller than maxout.	highlight must be in
       the range [0..maxin] and larger than shadow. Its default value is the same as maxin (16383 if not set).

       maxin defines the size of the gamma table. The size depends on the scanner/backend.  If the scanner uses 8 bit  gamma
       input then maxin must be set to 255, 1023 for 10 bits, 4095 for 12 bits, and 16383 for 14 bits. The default is 16383.
       To  find	 out what value maxin has to be, call scanimage(1) with a very large gamma table [0]0-[99999]255 and scanim‐
       age(1) will print an error message with the needed gamma table size.

       maxout defines the maximum output value. Take a look at the output of scanimage -h to find out what maxout  must	 be.
       The default value is 255.

EXAMPLE
       scanimage --custom-gamma=yes --gamma-table `gamma4scanimage 1.8 0 11500 16383 255` >image.pnm

SEE ALSO
       sane(7), scanimage(1)

AUTHOR
       Oliver Rauch

EMAIL-CONTACT
       Oliver.Rauch@Rauch-Domain.DE

							 10 Jul 2008					  gamma4scanimage(1)