nnevatie

Since my post, I've rewritten the part of my SW dealing with semi-transparent pixels. I'm basically using pre-multiplied alpha, which solves the original issue, as it doesn't matter what the RGB values are when alpha gets to zero. Nevertheless, it would be nice if Paint.net had a way of explicitly controlling the RGB and A channels separately - it took me a while to find the Overwrite blending mode, which essentially allows you to overwrite the destination pixels with any ARGB values, regardless of the source alpha.

Thanks for the response! My original problem had more to do with the alpha channel affecting the RGB values. However, I managed to get the zero-alpha pixels to the RGB values I wanted by changing the blending mode from "Normal" to "Overwrite". Case closed!

Hi, I noticed Paint.net sets the RGB values of fully transparent (A = 0) pixels to the triplet 255,255,255. Is this intentional? Is there a way of explicitly setting or maintaining the RGB values at a desired value? This is useful, for example, when creating a logo with black letters on top of transparent background. Currently the white-in-RGB pixels cause sub-sampling and scaling issues in my SW, as the white pixels get mixed in with the black logo pixels, causing a grey halo to appear on the area where the alpha drops to zero. I know this issue could be worked-around by weighting the sampling for zero-alpha pixels, but it seems weird such special handling would be required. Ideally, the user would be able to set the RGB values of zero-alpha pixels to any value, such as 0,0,0 in the above example case.