POV-Ray : Newsgroups : povray.binaries.images : bug or am I silly? : Re: bug or am I silly? Server Time
8 Aug 2024 08:12:58 EDT (-0400)
  Re: bug or am I silly?  
From: Lance Birch
Date: 1 Aug 2005 00:12:15
Message: <42eda11f$1@news.povray.org>
"Hall" <tre### [at] ww-interlinknet> wrote in message
news:42eceda8@news.povray.org...
> using pov-ray 3.6.1 for windows on windows XP...
> Should I be seeing the banding produced in this minimal scene file?
> (Is this a limitation of POV's precision, or a bug?  banding is stronger in
> original bmp of picture)
>
> camera { location <-4,4,-4> look_at <0,0,0> right <1,0,0> up <0,1,0> }
> light_source { <1,1,-1> color rgb 1 }
> plane { <0,1,0>, 0 pigment{color rgb 1} }
>
> and result....

Are you running an ICC profile on your monitor?

If you are seeing *colour* bands (such as slightly red, green, or blue hues when
compared with neighbouring bands) in this greyscale image (even after you
desaturate it, or convert it to a pure greyscale image, in a paint program), it
could be because you're running an ICC profile for your monitor and, in the
process of changing the output signal to make it match a specific response
curve/black point/colour temperature, is introducing slight variations in the
output hue.  Thus a specific output level like RGB 128, 128, 128, could become
129, 128, 128, causing one band to appear slightly red, while the one next to it
at RGB 127, 127, 127 could be changed to 127, 128, 127, making it appear
slightly blue.  This can also introduce (if the profile isn't accurate) larger
than normal steps in the lightness of bands.

Check your colour management to see if a profile is enabled - if it is, try
disabling it, restarting, and checking if the bands are gone (or aren't as
significant).

Lance.

thezone - thezone.firewave.com.au


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