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RE: filmscanners: VueScan 7.1.26 Available

Ed writes ...

> ...
> VueScan just multiplies the gamma and brightness numbers together and
> uses this internally as the exponent to the power function.  It's always
> worked this way, but hopefully having the two options back in the
> user interface will reduce the number of e-mails I get about this.

  When you originally removed this "feature" you put it into a context of
"having problems with it causing problems with color neutrality".

(1)  Did you fix this? and ...

(2)  How does Vuescan deal with color neutrality in general?  That is,
assuming you are working with the 3 RGB channels, the same "brightness"
applied to all three should alter hue.  If you apply the same "contrast"
scaler to all three it should alter saturation (and hue).  Similarly, apply
the same "gamma" to all three channels should cause similar problems.

  Presumably, these operations could be independently be applied to all
three channels if primarily applied(for example) to 'L' in "Lab" space, or
'L' in "HSL" space(?)  You have never mentioned using intermediate color
spaces ... without exposing Vuescan secrets, can you enlighten us?

shAf  :o)


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