How to make transparent backgrounds easier
dagorhir
Traveler
I'm trying to make tokens for VTT and I need to make the background colour transparent. I already found a thread that told me that CC3+ can't export PNG with transparent but the suggestions in that thread don't work.
I tried picking a colour like #6 and using gimp change that colour to alpha but that only destroys all other colours in the image. No matter what background colour I use, it simply changes all the colours.
So far the only thing I found was to manually delete the pixels I don't want. That is a long and tedious process prone to errors.
Any help would be much appreciated.
Comments
Off-hand I don't know what color #6 is but I would personally use something like a bright obnoxious pink, which I imagine is not within your portrait.
In Gimp, open your exported portrait and click Colors... Color to Alpha (4th from the bottom)
Next to "Color" (which starts white), click the color picker box.
important: It will give you a large square box and it will average all the colors within the box. After clicking in the image once, shrink the box size with '[' key. Make sure you pick ONLY the color you want to be transparent. Alternatively, you could also mess with the "Transparency Threshold" slider which will turn more and more colors transparent depending on how close to the selected color they are.
If you have shadows falling onto your background color you will have to adjust the "Transparency Threshold" because it won't all be one solid color. Also, if you want to keep shadows on top of the transparency from the token, it will either require a different process or you'll have to recreate them within GIMP.
If your tokens are designed to be round and not very complicated along the edges, you might also be able to throw the export into something like https://rolladvantage.com/tokenstamp/ - which will stamp out a circular region fairly easily.
What kind of image are you working with?
You need a reasonably high resolution original, especially if the edge is blurred. Can you show us an example?
That's exactly what I've been doing. Colour #6 is in fact bright pink. Is there a global Transparency Threshold?
Round tokens are not the problem, these I got down pretty good despite my very low skill with gimp.
By making the image as big as CC3 will allow and tweaking the threshold I managed to get most of the pinkish colour to go without destroying the other colours.
Once the image is scaled down to token size the pink isn't too obvious.
Thanks at Loopysue, that was helpful.
As you are using CC3 to generate the image, try exporting it with absolutely no antialiasing at all. That will help you mask the pink out properly.
I think I've always exported without antialiasing. I tried a new one and made sure of it this time and I still got the same result.
This is the original image export before editing.
This is the same image after the pink has been removed. Although it isn't apparent there are still a few pinkish pixels left around the edges. They completely disappear once the image is reduced.
I'm satisfied with final result.
It looks like the original skeleton image has antialiased edges and CC3+ is blending those with the magenta background. Try using a white background for this particular case, if possible. This might be a case where you're better off copying the original PNG file to a work location and manipulating that copy directly in your favorite image editing software without going through CC3+ at all.
It is certainly a lot easier if you open the png file in a bitmap editor.
I create and edit all mine in Affinity Photo, Affinity Designer, and GIMP - with occasional trips to Blender, which can render objects with a transparent background with or without antialiasing.