RGB and alpha channel value

Hi all, bmp files can not only hold the (3) RGB values of a pixel, but also a fourth number, the 'alpha' value (see http://en.wikipedia.org/wiki/Alpha_compositing).

Question: is there a way to extract this number pixel by pixel with FTN95/clearwin ?

johannes

I guess that it would depend on the context but as far as I know, ClearWin+ only uses 24 bit bitmaps. For a 'drawing surface', GET_POINT@ gets the bit value at a given point but I would expect this to be only 24 bit.

Hi Paul, I checked my bmp file and indeed found that it is a 32 bit one. Thanks for the hint. When I try to process it with my current FTN95 code (which works fine for <24 bit bmp), the result is just black. So I think you are right in saying that ClearWin can process only up to 24 bit.

Q to forum: Has anyone else experience with 32 bit bmps? A test file could be provided.

johannes