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 is 1.0, if the value is larger than 1.0 then the image gets 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 has to be in the range [0..maxin],
       highlight has to be 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 bits gamma input then maxin  has
       to be set to 255, for 10 bits 1023, for 12 bits 4095, for 14 bits 16383. The default is 16383.  To find out what value maxin has to be call
       scanimage with a very large gamma table [0]0-[99999]255 then scanimage prints an error message with the needed size of the gamma table.

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

EXAMPLE

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

SEE ALSO

       scanimage(1)

AUTHOR

       Oliver Rauch

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

								    10 Jul 2008 						gamma4scanimage(1)