How to remove jaggies when doubling image size?
Ben Cooper
Marc 'BlackJack' Rintsch
It's not that easy because you want Gimp to invent information that simply
isn't there.
One approach might be:
1. converting to grayscale (ALT+G)
2. double the size
3. blurring (Filters->Blur->Gaussian Blur)
4. use the levels tool (Image->Colors->Levels)
(insert a control point, drag it to the top and then move it left/right
until you think the "thickness" of the graphic is right)
5. convert back to b/w (without dithering!)
There will be still jaggies but a little smoother ones.
Ciao,
Marc 'BlackJack' Rintsch
Olivier Ripoll
> I'm doubling the size of a two-color (black and white) image. How do I smooth the resulting jaggies while still keeping the image two-color (without using anti-aliasing)? Dunno what I'm missing, this must be easy but I can't see how to do it.
What you ask is mathematically impossible.
But what you can do is allowing more than 2 colours, scale by two, and then go back to 2 colours. depending on the dithering, you will have different type of "jaggies"
Also in your preferences->environment->scaling->Cubic(slow)
Sincerely,
Olivier.
Calvin Mathew Spealman
Better than complaining is fixing what is broken or in need of
improvement. A plug-in could be created to do this and I don't think it
would be that difficult either, especially since its only two colors.
Flat verticle and horizontal edges are easy as pie. Just do normal
resizing. It's the angles that make you wonder. I would suggest
something like converting the image into a grid of points of colors.
The flat color areas (filled in) you remove and are left with outlines.
Expand that, fill in colors. Just draw the lines between points so
that if two black pixels are at diagonals, they will become a longer line...
I know I'm explaining it wrong.