1FTGAMMA(1)                  General Commands Manual                 FTGAMMA(1)
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NAME

6       ftgamma - screen gamma calibration helper
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SYNOPSIS

9       ftgamma
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DESCRIPTION

12       The  ftgamma demo program opens a window showing series of gray stripes
13       filled with solid color and checkered pattern of  pixels.   Your  moni‐
14       tor's  gamma value roughly corresponds to the horizontal position where
15       the solid and checkered stripes are equally bright when seen from  some
16       distance.   Three  brightness  targets are explored: 33%, 50%, and 67%.
17       If the input-output curve of your monitor does not follow  ideal  power
18       law  relationship, you might observe slightly different gamma values at
19       different brightness levels.  It is also possible to examine gamma val‐
20       ues for basic colors.
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22       Two  alternative patterns relevant to font rendering are also provided,
23       where slightly slanted lines are rendered using grayscale and  subpixel
24       anti-aliasing.   In  the  grayscale  case,  the  correct gamma helps to
25       achieve uniform perceived thickness of the lines.  The gamma value that
26       corresponds  to  vanishing moiré pattern is ideal for anti-aliased font
27       rendering.  In the subpixel  case,  the  correct  gamma  removes  color
28       fringes that remain even after LCD filtering.
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30       This program does not have any options.
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32       This program is part of the FreeType demos package.
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36FreeType 2.11.0                    July 2021                        FTGAMMA(1)