On Fri, Feb 21, 2003 at 10:30:02PM -0800, Daniel Rogers wrote: > Hmm, It is unclear to me how to add a mask input to an image op. Could > someone answer these questions for me: > > Is the mask rectangular? > Is it simply connected? > > Is it binary? > > If it's not binary, how should one blend the mask and image before > operating? It would be an additional grayscale image data input to ImageOp. It interpolates between the Op's full 100% normal operation (where the mask is 1.0) and where the Op is masked out so that the image is not affected (where the mask is 0.0). > I am kinda thinking that it might be easier to include a mask channel in > the ImageData, and use the scanline accessor functions to to snark the > image data that is not covered by the mask. This could be implemented > with no change to the existing ops, since they only work on a single > scanline at a time. All the work would be done in the scanline accessor > function, which wouldn't pass data that was masked. I dont think it goes as an additional channel in an ImageData (or an Image) object. But I guess the choice is whether it is something that individual ops handle, or whether it is a post/pre processing step that something like ImageOp (or an appropriate or subclass, like scanline accessor) handles. Calvin
