Engraving process Log

Posted on:December 26, 2023 at 03:57 PM

Jan 12 2024

starting to log images and things https://github.com/samelie/hacks-repo.wiki.git because it’s fast.

This Faun did very well. faun-6.625x10.25-72dpi-5

Dec 2 2023

This command produces i beleive the best results for the engraver.

docker run --rm --entrypoint /bin/bash -v /Users/sam/Documents/Syncthing/Engraving/Lovley:/imgs docker.io/samuelrad/potracemagick -c "magick /imgs/lovely.png -units PixelsPerInch -resample 72 -alpha remove -ordered-dither h6x6a -flop pgm:- | potrace --svg --flat --group --color=#000000 --opaque -t 0.0001 -O 0.001 -z random -u 1 -a 0.0001 -H 8.070866 -o /imgs/lovley-72-h6x6a.svg"

Sept 24 2023

Faun

Playing with halftone. It could be we want an even amount of black and white.

ordered-dither

Sept 10 2023

This could work…

docker run --rm -v /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/v4:/imgs dpokidov/imagemagick /imgs/faun-6x9-hd.png -flop -alpha remove -units PixelsPerInch  -resample 72   -grayscale rec601luma   -ordered-dither o4x4   faun-6x9-hd-dither-o4x4.png

convert /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/v4/faun-6x9-hd-dither-o4x4.png    pgm:-  | potrace  --svg --flat --group  --color=#000000 -t 0.001 -O 0.1 -z random -u 1  -a 0.1  -H 6 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/v4/faun-6x9-hd-dither-o4x4.svg

This could be interesting https://github.com/evestera/svg-halftone. But results won’t work because the white is the svg. We need to invert this somehow…

svg-halftone --spacing 0.8 --shape diamond --output-width 152.4 --output faun-6x9-hd.svg  /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/v3/faun-6x9-hd.png

Sept 4 2023

This could be the working setting for 6x9 prints. :white_check_mark:

Resameple to 72 density reaches the limit for the engraver. Full range of black to white.

convert -flop -alpha remove -units PixelsPerInch  -resample 72   -grayscale rec601luma  -ordered-dither h6x6a faun-6x9.png    pgm:-  | potrace  --svg --flat --group  --color=#000000 -t 1 -O 0.1 -z random -u 1  -a 0.1  -H 6 -o faun-6x9_h6x6a_p6.svg

png input

svg output

Aug 26 2023

Breakthrough.

  1. UCP can only handle so much resolution /or the laser cannot go to the DPI it says /or DPI gets lost in translation.
  2. -units PixelsPerInch -resample XXX is important & should be a factor2 number such as 128 because the dither size is also factor2 (h8x8a Halftone Screen (45 degree angle) , see docs)
  3. For a better print adjust levels in Photoshop of the png so make pure white highlights
convert -alpha remove -units PixelsPerInch  -resample 128   -grayscale rec601luma  -ordered-dither h8x8a /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-6x9-lvl-2.png    pgm:-  | potrace  --svg --flat --group  --color=#000000 -t 1 -O 0.1 -z random -u 1  -a 0.1  -W 6 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-6x9-lvl-2_h8x8a_128.svg

Above image is an .svg file

Aug 24 2023

convert -alpha remove -units PixelsPerInch  -resample 300  -gamma 0.8,1.3,1.0  -grayscale rec601luma  -ordered-dither h8x8o /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-6x9.png    pgm:-  | potrace  --svg --flat --group  --color=#000000 -t 1 -O 0.1 -z random -u 1 -W 6 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-6x9_h8x8o_300.svg

Early days

convert -alpha remove -level 0%,100%,2.0   -ordered-dither h6x6o  /Volumes/BaeDrive/Engraving/ENGRAVINGS/medusa-scream/medusa-solo.png  pgm:-  | potrace  --svg --flat --group  --color=#000000 -t 1 -O 0.1 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/medusa-scream/medusa-soloh6x6o.svg

First image

convert -alpha remove -gamma 0.8,1.3,1.0 -level 0%,100%,1.0  -grayscale rec601luma  -ordered-dither h6x6o  /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-7x8.png  pgm:-  | potrace -W 6.8 --svg --flat --group  --color=#000000 -t 1 -O 0.1 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-7x8h6x6o-W.svg

28% Raster laser power

Second

convert -alpha remove -gamma 0.8,1.3,1.0 -level 0%,100%,2.0  -grayscale rec601luma  -ordered-dither c7x7w  /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-7x8.png  pgm:-  | potrace -W 6.8 --svg --flat --group  --color=#000000 -t 1 -O 0.1 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-7x8_c7x7w-W.svg

50% laser power

Third

convert -alpha remove -gamma 0.8,1.3,1.0 -level 0%,100%,2.0  -grayscale rec601luma  -ordered-dither h8x8a  /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-7x8.png  pgm:-  | potrace -W 6.8 --svg --flat --group  --color=#000000 -t 1 -O 0.1 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/faun/faun-7x8_h8x8a-W.svg

70% laser power

Apollo Commands

Sept 5 2023

Preparing the image correctly is everything. Here Posertize at 12 and get enough white on the image.

And now the result. We have enough pure white and blacks to make the engraving pop. It would have been nice to more contrast on the muses, but that is the price with a large image. Would need to use layer masking adjustment ?

Eden supplicants

Aug 26 2023

  1. 6x9 image
  2. Resample, svg and rescale to size. h8x8a 1. 
    convert -alpha remove -units PixelsPerInch  -resample 300  -gamma 0.8,1.3,1.0  -grayscale rec601luma  -ordered-dither h8x8a  /Volumes/BaeDrive/Engraving/ENGRAVINGS/eden_suplicants/eden_suplicants.png   pgm:-  | potrace  --svg --flat --group  --color=#000000 -t 1 -O 0.1 -z random -u 1 -W 6 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/eden_suplicants/eden_suplicants_h8x8a_300.svg
    1. 120Mb svg , insane detail
    3. This seems manageable.
  3. Resample, svg and rescale to size. h8x8o 
    convert -alpha remove -units PixelsPerInch  -resample 300  -gamma 0.8,1.3,1.0  -grayscale rec601luma  -ordered-dither h8x8o  /Volumes/BaeDrive/Engraving/ENGRAVINGS/eden_suplicants/eden_suplicants.png   pgm:-  | potrace  --svg --flat --group  --color=#000000 -t 1 -O 0.1 -z random -u 1 -W 6 -o /Volumes/BaeDrive/Engraving/ENGRAVINGS/eden_suplicants/eden_suplicants_h8x8o_300.svg
    1. 57Mb svg

h8x8a seems like a good value.