make background transparent in paint.net

Make background transparent in paint.net how to#

The actual solution is to compute the new color and alpha relieve to the image color alpha-blended to the selected color. ONE MORE EDIT: What I believed I confirmed is not true. I'd always thought that was the case, but I finally went through the math, and (believe I) confirmed it.

Accounting for the pixel alpha is easy: it's just a matter of scaling the computed alpha by the pixel alpha.

Make background transparent in paint.net how to#

I know how to do that, but I'll have to experiment to find the best way to minimize the annoying off-by-one errors that occur due to rounding differences. (ANOTHER) EDIT: I'm pretty sure that Make Transparent doesn't do what I'd like it to do, which is to change the transparency and color of each pixel in a manner that minimizes alpha while producing the original color when alpha-blended to the specified background color. The appearance of the selected region shouldn't change. If it doesn't work as it ought to, I'll probably make a new plugin.įill the upper layer with (200, 200, 200)įill the lower layer with (100, 100, 100) If someone else could run the little test I described above, I'd appreciate it. Still, I thought I'd previously tested the plugin and found it worked as it should. I thought it might be because I made some experimental changes, but I re-downloaded the original DLL, and believe I'm using that version. Video of the Day Step 2 Choose whether to click the 'Magnifying' tool on the 'Tools' palette on the left side of the screen, then zoom in on the area to make transparent. If I place a (200, 200, 200) gray layer over a (100, 100, 100) gray layer, then apply Make Transparent to the top layer with the color set to (100, 100, 100), the apparent color changes. Step 1 Open Paint and click 'File,' then 'Open.' Browse to a photo to make transparent, then double-click it so it opens in the Paint workspace. Perhaps I'm confused, but I don't think Make Transparent always works correctly. InteropServices namespace MakeTransparentEffect Forms using PaintDotNet using PaintDotNet. This is still really simple, and you don't have any other parameter than the color yet. Now I applied a dark background (just by adding a layer under the image, and filling it with the color) and the image looks like if it was the night Here the image is really transparent (you might want to open it in Paint.NET to see better) and can blend really well on any background. Then I applied my filter choosing some random blue color I could find in the sky of the picture: This can be used, for example, to change the background color of an image. The closer a pixel's color is to the chosen color, the more transparent it will become. I don't think this effect already existed (maybe I din't search enough), so I wrote this little effect today.īasically, this takes an opaque image along with a background/transparent color, and makes the image transparent in respect of the chosen color.