Removing white from scanned drawings.

I’m working with a few people who really love drawing on paper, then scanning the resulting animation into harmony. They always have at least one animation layer, and a BG.

I’m very hesitant to use Toon Boom’s ‘vectorise’ scanning option, because it just makes so many points. So so many points. All I want to do is have my opaque drawing, then take out the white.

Right now, we’re using a transparency set to about 60-75 (depending on the scene), and sometimes a brightness-contrast module.

Unfortunately, it’s not super great, because the lines get fainter.

Is there a way to just set white pixels = transparent? I’ve googled various things, and I can’t find anything that helps.

I really hope that there is another way to do this, other than vectorise, or bringing it in to photoshop (they will just never do this.)

Thanks for any help!

Can’t you convert the drawings to vector first, and then convert back to bitmap?

Something to try, for sure! It would be interesting to see what exactly happens to the line art in that case.

Unfortunately, the people who like drawing on paper aren’t really in to the whole computers thing, so I’m hoping there’s a simple module out there that can help.

I just found the ‘blending’ module, and it might work. Though it doesn’t seem to do anything in the OpenGL view, and only affects the render. Unfortunately, these artists will typically just test the animation in toonboom itself, and not render out a quick test to see.

So something like the blending module that is visible in the open GL would be great. I’m checking to see if there are any options I can tick that will let this, but I don’t see any.

Thank you hvanderwegen for the suggestion.

If you use the Luminance-Threshold node you can key out the white of the paper.
The vanilla node already works pretty well without modification but you can tweak
it depending on the qualities of the drawing. See the image in the link for the
setup. The RenderPreview is just there so that you can see it in the OpenGL view.

Do you have to scan coloured drawings or you can colour them in Harmony? If you want to scan a textured line Harmony will make the drawings transparent, that is, removing the white from the paper, and retaining the textured line. Then you would have to colour them in Harmony. If your workflow requires some blending effect you have to deal with possible unwanted changes. Blending-Multiply will remove white, but it affects colour. It’s good for black on white background. There’s also the Chroma-Keying module that you can try.

Luis Canau