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+--- Thread: Custom shapes for Newsprint Filter (/Thread-Custom-shapes-for-Newsprint-Filter)
Custom shapes for Newsprint Filter - rospo - 11-07-2017
Hi all,
I am wondering how I can add custom shapes (not round, line, diamond, or square) to the newsprint filter.
I would like to rasterize an old grayscale photo using five-pointed-stars.
- Can it be done in gimp using the newsprint filter?
- How can we add custom dot-shapes to this filter?
- Suggestions for work-arounds?
RE: Custom shapes for Newsprint Filter - Ofnuts - 11-07-2017
1) No because 2),
2) No as far as I can see you can't without changing the code and rrecompiling
3) maybe my luminosity-tiler script (there is an equivalent function in GMIC). See examples here (but discuss here on Gimp-Forum if needed)
RE: Custom shapes for Newsprint Filter - rich2005 - 11-07-2017
(11-07-2017, 12:26 AM)rospo Wrote: [*]Suggestions for work-arounds?
You can get a sort of pseudo-halftone effect, all depends on your greyscale image size. The larger the better.
First problem is the star, needs to be small which results in less-than-star-like shape.
This one 16x16 pix on transparent background, then copied to the clipboard and used as the clipboard pattern
[attachment=920]
Open the greyscale image then transparent layer on top. Filled with the star pattern, Layer mode set to Overlay
[attachment=921]
The next bit you will have to take my word for:
Still on that star layer Layer -> Transparency -> Alpha-to-Selection then invert the selection Select -> Invert
With the selection still active create a new from visible Layer -> New from Visible
On that new from visible layer, with the selection still active fill with white.
Kill the selection, Select -> None Put the layer into Hard Light mode.
Turn visibility of the middle layer off.
[attachment=922]
Why pseudo half tone? Strictly the stars should be sized according to luminosity.
RE: Custom shapes for Newsprint Filter - Espermaschine - 11-09-2017
There are a few halftone filters in G'MIC. I think one of them also has a star.
EDIT: yes, its the Op-Art filter. Thats under 'Patterns'.
You can also use Inkscape to make a halftone with tiled clones tracing an underlying image.