Make white part of a drawing transparent, help with GIMP!

Hello

I have been drawing mandalas like you see in the picture.

I need to remove the white background and only have the black lines.

I have tried different things in GIMP and seen some videos, but I can’t seem to figure out how to remove the white background.

I really need to have a step by step for only that - can someone please help?

Hello, welcome. I don’t see any picture, so difficult to help you!

There was no example image attached to your post - do you have a sample you can show us?

For the most part it’s usually just making sure the layer has an alpha channel for transparency:

Or directly using Color to Alpha from the same menu:

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Here is a picture :slightly_smiling_face:

I think my problem is, that there are so many steps and it does’nt make sense to me - but I do try and will again from your answer.

In my mind I should just be able to choose to keep all the black color, delete the rest and then save as jpg.

Hi @Lisel, and welcome!

It may be sacreligious, but
have you seen what the interesting filters
in The Gimp/Filters → G’MIC-Qt can perform?

Have fun!
Claes in Lund, Sweden

Yes I have - but it’s not good enough.

This worked really good - thank you!

BUT - now the image size is very small and not that good for printing on a pillow or other kind of present.

???
How do you save or export the modified Mandala from The Gimp?

Hello @Lisel,
have a look at Inkscape. It works with vector graphics. Probably the much better tool for manalas.

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I export the file - is that wrong?

Wait, what? None of the things I linked should change the dimensions of the image.

Oh, another option would be to select all the white color with the Select by Color Tool and then delete it.

image

Side note - no matter what you do, JPG doesn’t support transparency, so you’ll need to export to something that does, like PNG.

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Look here:
https://designbundles.net/design-school/how-to-create-a-mandala-heart-in-inkscape

Gimp is very good and important for me. But the graphics of a mandala you can do much better with a vector graphics program like inkscape.
You will find countless tutorials on the net and be thrilled.
Have the courage to work with inkscape, Gimp will not suffer because of it.

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As @patdavid says, JPEG files can’t record transparency.

There is another problem. If you look carefully between the white and black areas, pixels are various shades of gray. If you simply make white pixels transparent, the gray pixels will remain, creating a sort of light halo around the dark areas. This may, or may not, be a problem.

If it is a problem, there are many possible solutions. One is to regard the black-gray-white image as transparency, which we can negate to be opacity, and then make all the pixels black (but with varying transparency).

I expect that can be done with Gimp. I know ImageMagick better than Gimp, so here is an IM command (Windows syntax).

magick lisel102.png -negate ( +clone -fill Black -colorize 100 ) +swap -alpha off -compose CopyOpacity -composite out.png

If your browser background is black, the black lines on a black background won’t show well. But any other colour will look good, with no “light halos”.

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I know it is not the method you asked for, but have you considered converting to an SVG via a free online converter? SVGs are vector based so you can scale it as large as want an not get any pixilation or jpg artifacts.

A quick Google search gave me this one PNG to SVG (Online & Free) — Convertio
45e0bfe99bd9f29dc914c9fee3653b317ae27601_2_1035x1035

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THIS!

This was everything i needed. So easy and the PNG in the end is in a perfect size.

Thank you :slight_smile:

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Yes, your question was how to make your mandalas with Gimp. That seems to be answered.
In addition, if you had an interest in Inkscape, here are a few simple mandalas I made for myself a few years ago. You can look at them with Inkscape and use them as you like, maybe you’ll get a taste for it after all …


M-20150804
M-20150806
But of course vector based graphics are less sensual than the pixel based ones from Gimp. Have a look and have fun with it.
M-20150810
M-20150816