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PAID: Dither Convert

Posted: 2015-04-14T18:04:40-07:00
by DitherMyImages
Hi Everyone, I'm looking for a ImageMagick Consultant who can build me a command line command that will give me the correct dither output that I'm looking for.
Please PM me for details

THANKS!

Re: PAID: Dither Convert

Posted: 2015-04-14T18:13:43-07:00
by fmw42
I don't think I can help. But have you looked at this page to see if what you need is discussed. see http://www.imagemagick.org/Usage/quantize/

Re: PAID: Dither Convert

Posted: 2015-04-14T18:20:16-07:00
by DitherMyImages
fmw42 wrote:I don't think I can help. But have you looked at this page to see if what you need is discussed. see http://www.imagemagick.org/Usage/quantize/
Im on it right now... Im not getting the results i want

Thanks for the link regardless :)

Re: PAID: Dither Convert

Posted: 2015-04-14T18:36:20-07:00
by fmw42
There are lots of different dither methods there. I was hoping that one would be what you needed.

Re: PAID: Dither Convert

Posted: 2015-04-15T00:09:25-07:00
by dlemstra
It might help if you specify what you consider the 'correct' output.

Re: PAID: Dither Convert

Posted: 2015-04-15T03:54:10-07:00
by DitherMyImages
dlemstra wrote:It might help if you specify what you consider the 'correct' output.

Sorry dlemstra, I was going to send over the images to someone once I heard back. Since we are laser engraving , the photo needs to be dithered in halftones , since any grayscale in the image will simply be converted by the laser driver and cause unreliable results.

The photo also needs to be between 500dpi and 1000dpi

The photo I'm posting is the unedited version and the correctly dithered version that engraves very well.

Thanks!


Image
Image

Re: PAID: Dither Convert

Posted: 2015-04-15T04:24:12-07:00
by snibgo
These are two different photos, most clearly seen by comparing feet. Posting the same photo before/after treatment would help.

The "after" photo also seems to be heavily sharpened.

Re: PAID: Dither Convert

Posted: 2015-04-15T04:32:15-07:00
by DitherMyImages
snibgo wrote:These are two different photos, most clearly seen by comparing feet. Posting the same photo before/after treatment would help.

The "after" photo also seems to be heavily sharpened.
Sorry , I changed the link to the correct file...

There may be a few things going on with the image that are outside of my scope and understanding. The software we use to convert this image is designed by the laser manufacturer and they obviously do not divulge any of the algorithm. It doesn't need to be exactly the same but dither pattern works extremely well when engraved.

Thanks!

Re: PAID: Dither Convert

Posted: 2015-04-22T20:38:19-07:00
by glennrp
I couldn't reproduce your output exactly, but here are a couple of things you can try:

Code: Select all

convert original.jpg -gamma 1.5 -negate -colorspace gray -ordered-dither 6x1 halftone.jpg

convert original.jpg -gamma 1.5 -charcoal 3x2 -negate -colorspace gray -ordered-dither 6x1 charcoal.jpg