PNG - Images getting mangled with "-colors 256"

Swiss army knife of image processing

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#328 PNG - Images getting mangled with "-colors 256"

Milestone: v1.0_(example)

Status: open

Owner: Glenn Randers-Pehrson

Labels: None

Priority: 5

Updated: 2017-03-04

Created: 2015-11-30

Creator: score_under

Private: No

Some images get mangled during conversion when "-colors 256" (or lower) is specified.

"gm convert -colors 257 test.png out.png" works fine, but "gm convert -colors 256 test.png out.png" mangles it.

In actual usage I am using +dither as well, but I've noticed this makes no difference to whether or not the bug takes effect.
I've attached an image capable of triggering the bug.

1 Attachments

test.png

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Bob Friesenhahn - 2016-01-28

assigned_to: Glenn Randers-Pehrson
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Bob Friesenhahn - 2017-03-04

summary: Images getting mangled with "-colors 256" --> PNG - Images getting mangled with "-colors 256"
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PNG - Images getting mangled with "-colors 256"

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#328 PNG - Images getting mangled with "-colors 256"

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