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Greyscale image to bitonal

https://imagemagick.com/discourse-server/viewtopic.php?t=7308

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Posted: 2006-08-31T04:37:30-07:00
by glennrp
  • -threshold

Posted: 2006-08-31T19:57:28-07:00
by anthony
If the pixels are pure and your IM is a Q16 then use..

Code: Select all

2^16 - 2   => 65534
EG:

Code: Select all

-threshold 65534
or more simply for all IM Q, negate the image threshold and negate back, so you don't have to deal with the color range.

Code: Select all

 -negate  -threhold 0  -negate
NOTE: if you want to make ALL pixels black, use a -threshold of '-1'
See
http://www.cit.gu.edu.au/~anthony/graph ... vas/#other
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