how to handle transparent parts of layers?
Posted: Thu Aug 31, 2006 8:37 am
Does anyone know the right way to handle layers in a filter plugin so as to preserve the colors at the semi-transparent edges of the opaque parts of a layer?
It seems the inData I get from the plugin host (Photoshop or PSP) already has the image composited (based on the alpha channel) with a white background. So even if I just copy all the RGB and alpha data I get from inData back to outData, I end up with light-colored edges around the non-transparent parts of the layer. Telling the host that I only want to handle the RGB planes (by setting inHiPlane=outHiPlane=3) doesn't seem to work either.
It seems the inData I get from the plugin host (Photoshop or PSP) already has the image composited (based on the alpha channel) with a white background. So even if I just copy all the RGB and alpha data I get from inData back to outData, I end up with light-colored edges around the non-transparent parts of the layer. Telling the host that I only want to handle the RGB planes (by setting inHiPlane=outHiPlane=3) doesn't seem to work either.