gamma4scanimage.1

---

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
 scanimage(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)

---

Man(1) output converted with man2html