Programmatically Manipulate Bitmap in Photo Paint?

Is it possible to programmatically manipulate a bitmap/image/picture in Photo Paint?  In other words, read the pixels of the bitmap, do some calculations and write a new bitmap? I am trying to do a purple filter (hue=300), similar to a red, green, or blue filter. I haven't found where to get at the pixels is this beyond VBA or VSTA can do in Photo Paint?