Subject: imagemagick: Imagemagick -fft produces a white image for the magnitude image.

From: Martin Hodges <[email-masked]>
Date: Mon, 23 Oct 2023 23:04:57 +0200

Package: imagemagick
Version: 8:6.9.11.60+dfsg-1.3+deb11u1
Severity: normal
X-Debbugs-Cc: [email-masked]

Dear Maintainer,

The -fft conversion previously produced a very dark magnitude image. The 
present versions 
magnitude image is very light.
Testing with the 8x16 white rectangle on black background produces an image 
which appears 
to be related the image shown on https://www.imagemagick.org/Usage/fourier/
Section:- Spectrum of a Rectangle Pattern Image, but the non-black areas have 
been increased
in value so much that there is almost no grey.

Version 6.9.10-23 performs the conversion as expected.

-- Package-specific info:
ImageMagick program version
---------------------------
animate:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
compare:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
convert:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
composite:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 
https://imagemagick.org
conjure:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
display:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
identify:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
import:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
mogrify:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
montage:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org
stream:  ImageMagick 6.9.11-60 Q16 x86_64 2021-01-25 https://imagemagick.org

-- System Information:
Distributor ID:	Devuan
Description:	Devuan GNU/Linux 4 (chimaera)
Release:	4
Codename:	chimaera
Architecture: x86_64

Kernel: Linux 5.10.0-26-amd64 (SMP w/4 CPU threads)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), 
LANGUAGE=en_GB:en
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages imagemagick depends on:
ii  imagemagick-6.q16  8:6.9.11.60+dfsg-1.3+deb11u1

imagemagick recommends no packages.

imagemagick suggests no packages.

-- no debconf information

---

From: Mark Hindley <[email-masked]>
Date: Tue, 24 Oct 2023 19:05:28 +0100

Control: tags -1 debian

Martin,

Thanks for this.

> X-Debbugs-Cc: [email-masked]

Devuan does not fork src:imagemagick and uses Debian's packages directly without
recompilation. Please report this issue directly to the Debian BTS to be
addressed.

Thanks

Mark