Possible bug IM 7.0.8.60 with resize, attenuate and noise

Post any defects you find in the released or beta versions of the ImageMagick software here. Include the ImageMagick version, OS, and any command-line required to reproduce the problem. Got a patch for a bug? Post it here.
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fmw42
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Possible bug IM 7.0.8.60 with resize, attenuate and noise

Post by fmw42 » 2019-08-12T16:04:31-07:00

I am getting a different and bad result from IM 7.0.8.60 Q16 Mac OSX and IM 6.9.10.60 Q16 Mac OSX as follows. It happens only if -resize is smaller than 100% (tested with 35%, 70% and 99%) or no resize. Note the extraneous white lines/curves. (Some odd overshoot?)

Input:
Image

IM 6:

Code: Select all

convert bw_flower2.png -resize 99% \
-channel rgb +noise gaussian +channel bw_flower2_6.png
Image

IM7:

Code: Select all

magick bw_flower2.png -resize 99% \
-channel rgb +noise gaussian +channel bw_flower2_7.png
Image

If I remove the +noise gaussian, it goes away or if I use -resize 100% it goes away.

User avatar
fmw42
Posts: 25274
Joined: 2007-07-02T17:14:51-07:00
Authentication code: 1152
Location: Sunnyvale, California, USA

Re: Possible bug IM 7.0.8.60 with resize, attenuate and noise

Post by fmw42 » 2019-08-20T18:24:11-07:00

This still fails in IM 7.0.8.61 Q16 Mac OSX.

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