I've just posted in my weblog at Foxite a small article about applying special effects to images with Gdi+, with the use of ImageAttributes and ColorMatrices.

To make things easier, I've created a small wrapper class to access these functions that are not present in _gdiplus.vcx. This way it becomes really easy to apply some effects such as control Brightness, Saturation, Hue, Contrast, convert images to GreyScale, Negative, create Masks, work with transparencies, etc.

I've called this class GPATTRIB, and it works together with Nichols' _gdiplus.vcx from VFP9 and with Golovlev's GPIMAGE (for old VFP version users).

Maybe some of you can find it useful.
http://weblogs.foxite.com/cesarchalom/

Regards

Cesar