Image treshold

[Scott David Daniels]

Johny wrote:
> Can anyone give me an example how to apply a threshold value to an
> image?
> (everything above a certain brightness level becomes white, and
> everything below the level becomes black.)
> I was told I should use 256-item mapping table and pass it to the
> "point" method.
> But how should the 256-item mapping table  look like, if the threshold
> is 18( found from the histogram)

Sounds like homework.  You have the tools, and are close to the answer.
Experiment and look at the results.

-Scott