L_ColorThresholdBitmap

It seems, that it works with "OR" logic between color components.
How to use it with "AND" logic ?
I need to found "near-to-black" images (dark reds, greens, yellow, etc) and change thems to black. all other pixels should be untouched.
it seems, it could be processed with 1 library call in HSV colorspace, but "AND" logic required.
Or, more suitable way exists ?

John,
There is an easy approach to do your requirements. You can use the L_SetBitmapRgnColorHSVRange() function to create a region that contains all "near-to-black" colors. After that, you should call the L_FillBitmap() function to fill the region that you create with the black color.
For more information about L_SetBitmapRgnColorHSVRange() and L_FillBitmap(), please see them in our main C DLL help file that is shipped with the toolkit.

Thank you, this really helpfull.

I have another questions:
1. Assume, that some region selected.
How to detect that pixel inside region or not ?
Also, it would be very useful to have some iterator (or callback function), that called for each pixel inside region. I think, this will greatly reduce processing time. Possibly, you already have this functionality.

For example, construction like this:
for each pixel in region do
do some pixel processing
enddo

John,
Most of our image processing functions will only affect the region if it's defined. If you need these functions, using them would be much faster than working on every pixel alone. The loop that accesses individual pixels like that would most likely be very slow compared to our image processing functions.

If you have questions related to processing other than the Fill function we discussed here, please send the details of your question in an email to support@leadtools.com or open a separate forum thread for each issue.