Brightness and Contrast

Marten van den Berg mons at
Wed Jan 16 05:25:01 EST 2002

op 15-01-2002 07:22 schreef Jeanne A. E. DeVoto op jeanne at

> At 2:30 AM -0800 1/14/2002, Marten van den Berg wrote:
>> I could't find a description of the imageData property in my transcript
>> dictionary (I'm using rev 1.1).
> I had forgotten, there's a bug in the 1.1 version. The imageData property
> is in there, though, and you can get to it by typing "imagePixmap" into the
> search box at the tiop of the dictionary, then pressing the left arrow to
> go back one card.

> I'm thinking it would be possible to process this data in a repeat loop,
> altering each run of four bytes and then writing out the altered values.

Thanks, I found the description linked by the alphaData property.
I already tryed to perform such a repeat loop for the brigthess case, but an
imagae has a lot of pixels to process. I works but is far to slow. For now
I'm using a white and a black image blending over the original image which
works fine for displaying, but actualy I want the possibility to alter the
original image.
In graphical editing programs these things can be done in realtime, so
somehow this must be posible too in revolution, perhaps by an external.
I'm inexperianced in writing code other than hypertalk/transcript. If anyone
could help me out on this I would be very greatful!

Marten van den Berg

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