: Converting anti-aliased to alised image in gimp I took a screen-shot of an image and want to edit it, but I am having a problem with edges, that it is ant-aliased. How can I remove anti-aliasing

@Dunderdale640

As others said, you usually want to keep the anti-aliasing.

If you want to remove it nevertheless, and if the image is on a uniform background:

1. Remove the background using Color to Alpha


Add an alpha channel if necessary: Layer → Transparency → Add alpha channel.
Fuzzy-select the background
Select → Grow by two pixels
Use Colors → Color to Alpha to remove the background (note down the RGB values of the color you removed)
Select → None (important for what follows)


2. Change the opacity using a layer mask:


Add a layer mask: Layer → Mask → Add layer mask and initialize to Transfer layer’s alpha channel.
Use the Threshold tool (Tools → Color tools → Threshold) to threshold the layer mask (it should normally apply to the layer mask at that point, otherwise, click on the layer mask preview in the layers list).
If/when happy with the result, Layer → Mask → Apply layer mask.


3. Restore the background


Set the foreground color to the color your removed in the color-to-alpha step.
Set the Bucket Fill tool to Behind mode (Mode: selector at top of tool options), and bucket-fill the layer.

Vote Up Vote Down