I think I now have all the steps I need. Thank you everybody.
Somewhat away from my original question and not my specific goal, but key to it if anyone else is interested...
To simulate CMYK process* using GIMP and Inkscape:
In GIMP:
- decompose RGB image to CMYK layers
- create image mask for each layer and initialise with Grayscale copy of layer
- convert layers back to RGB
- flood fill each layer with its process colour (select cmyk with the palette selection buttons above sliders)
- turn off visibility for other colours and export a png for each layer
In Inkscape:
- import the png's
- create separate layers for each process colour
- set each layer's Blend mode to Darken or Multiply
- move each png to it's corresponding layer
- align the images
- ...and viola!
Finally, to disable antialiasing for pixel level control, set
Image Rendering to
crisp-edges in
Object properties.
* Please note, not recommended for prepress!
The whole option was to simulate a CMYK process. Nice workflow. I get it, but I don't understand what you mean by 'crisp'. In Inkscape 'Image Rendering' I only find this options : auto, optimiseQuality, optimiseSpeed. In Inkscape I still don't see 'crisp' bounderies (see example done in gimp):
[
attachment=8979]
(11-07-2022, 09:51 AM)denzjos Wrote: [ -> ]The whole option was to simulate a CMYK process. Nice workflow. I get it, but I don't understand what you mean by 'crisp'. In Inkscape 'Image Rendering' I only find this options : auto, optimiseQuality, optimiseSpeed. In Inkscape I still don't see 'crisp' bounderies (see example done in gimp):
Thanks.
Is this crisp edges? No. In addition to the options you list, mine has
crisp-edges and
pixelated.
I'm using an AppImage of Inkscape
v1.0 (4035a4f, 2020-05-01) ...which seems like a weirdly low number, but that's what the about dialog says...
I'd be interested to know what version you're using. Nothing worse than relying on a feature in an app then finding it's been dropped by the developers!
You could try upgrading or downgrading, as the case may be..
Exported a 20x20 1-bit BMP from GIMP. It has a 45 rotated square in the middle and a pixel in each corner.
Here it is in bash...
Code:
tail -c +62 1bit-diamond-20x20.bmp | hexdump -v -e '/1 "%u\n"' | xargs -I {} echo -e "obase=2\n{}" | bc | xargs printf "%8s" | sed 's/[0 ]/_/g' | while read -n 32 row ; do echo "$row" ; done
__________1111111111111111______
__________1111111111111111______
________11111111111111111111____
________11111111111111111111____
________111111111__111111111____
________11111111____11111111____
________1111111______1111111____
________111111________111111____
________11111__________11111____
________1111____________1111____
________1111____________1111____
________11111__________11111____
________111111________111111____
________1111111______1111111____
________11111111____11111111____
________111111111__111111111____
________11111111111111111111____
________11111111111111111111____
__________1111111111111111______
__________1111111111111111______
@bitrat, I installed the current stable inkscape version and now I find crisp-edges and pixelate in the object properties. The version I used was 0.9
