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B1ackwater · Guest

Hello,

I've been fooling around with the ScanLine function trying
to get RGB values for pixels in a bitmap. The documentation
is a bit on the thin side about the particulars however -
I know that the pByteArray format changes as the color
depth of the image changes. One source says it doesn't
return 'real' colors but instead an index to a palette or
lookup table that can be translated into solid RGB values
somehow.

The few examples on the web I've found are mostly demos on
how to just invert every value - what *I* need to do is a
kind of contrast operation ... turn all pixels darker than
a certain threshold pure black, and lighter than that
threshold all white. Just switching the bitmap to mono mode
doesn't cut it - I get greys - and there doesn't seem to be
a way of setting the black/white threshold point for 1-bit mode.

I'm bringing in 24-bit JPEGs and want to wind up with a 256 color
bitmap that's at 100% contrast. I'll need to put colors on the
mono image as markers later on.

Still using Dephi-5 (can't afford anything newer).

Anyway, if anyone knows of some good examples on the web of
people using ScanLine to get values for image-processing
type operations, please post them here. Thanks.

Riki Wiki · Guest

Hoi

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