xenial (1) gamma4scanimage.1.gz

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)