Author Topic: Question about color vs grayscale bitmap  (Read 746 times)

So I have a question.

When importing a bitmap image, it defaults to color. Which is fine. The imported bitmap has a transparent background and is black & white (edges are aliased) - see screenshot.

When I switch the bitmap to Grayscale, the antialiasing vanishes - see other screenshot

Is there a reason it does this? Can't I retain the antialiasing in grayscale?

I'm essentially trying to work in grayscale as much as possible first before introducing color

This is probably just how the image was saved. The pixels get recorded as black or white, and their transparency/translucency is recorded as another channel entirely. The system is probably just discarding the translucency channel, and what's left is black (which your shapes are) until the pixels hit 0 visibility, where it won't have been recorded and so defaults to white.

What you can do is use a Blend node to combine the black, translucent bitmaps with a white plain color, white on the bottom, and then convert that to grayscale. That should solve your problem.


hey, did you just try to plug a grayscale conversion node?

I'm fine using color. I was just curious as to why the grayscale option of a bitmap does that. The removal of the transparency would explain it, but why does it remove the transparent channel?

I'll give the blend a shot. It would be better to work in grayscale for longer compared to using color processing through each node.

I'm going to double check with the dev team to see if it's the expected behaviour

Good on you Vincent. Thank you.

I ended up blending color-bitmap with a uniform color (white) then converting that to grayscale to maintain the antialiased gradation. From there I can use it as a mask, or whatever.