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Anti-aliasing

Posted: 2014-04-07T05:41:59-07:00
by mad_b
Would it be feasible/easy to allow me to choose when NOT to use anti-aliasing?
Particularly, I would like to make a SHEAR operation on an image, *without* anti-aliasing. It seems the source code that says to be based on a paper, did not follow the paper that had an if test allowing the user to choose whether not to use anti-aliasing.
I am trying to work with B&W images that get terribly damaged when sheared with anti-aliasing (the default mode of IM).
I need to shear the image that will be "de-sheared" by another processing step, but the current IM shear process add lots of middle tones in the processing step, that ruin the next processing step in my use case.

Thanks
Lissandro

Re: Anti-aliasing

Posted: 2014-04-07T10:13:23-07:00
by fmw42
What version of IM and what platform? What was your exact command?

try

Code: Select all

convert image -filter point -shear ... result
or

Code: Select all

convert image -interpolate nearestneighbor -shear ... result