Hi Guy, On 1/12/10 3:58 , Guy Volckaert wrote: > I noticed that the alpha component in the BMP file (when RGBA or BGRA) is not > being > preserved in the image. I would like to proposed the following small change > to correct > this problem. Instead of ignoring the alpha component, I first check if the > bytesPerPixel > == 4 bytes. If so, then I simply copy the row alpha to the image alpha > component. > > Does that make sense? Or am I not following the BMP standard?
The bmp reader is only evaluating the V3 header that doesn't specify alpha, so it's always possible for something to break. However, this looks like it should still be okay. I tested my bmp patches against the files from http://wvnvaxa.wvnet.edu/vmswww/bmp.html (the compressed ones don't work IIRC). Cheers, /ulrich > Code: > >... > if (imageBytesPerPixel == 4) > { > // ********* THIS IS MY CHANGE******* > if( bytesPerPixel == 4 ) > { > imgp[3] = rowp[3]; > } > else > { > imgp[3] = 0xFF; > } > } > } > imgp += imageBytesPerPixel; > rowp += bytesPerPixel; > } > } > } _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
