[Pkg-gmagick-im-team] Bug#940271: display: selecting the area for crop is very slow on a big image (regression)

[Vincent Lefevre]

Package: imagemagick-6.q16
Version: 8:6.9.10.23+dfsg-2.1+b1
Severity: normal

1. Open a big image with "display", e.g. of size 2124x1800.
2. Click on the image to make the menu appear.
3. Click on "Transform", then "Crop".
4. Start to select an area.

The rectangle flickers for several seconds (this can be more than
20 seconds) to get the final selected area. This makes "crop"
almost unusable, and it is even impossible to do an accurate crop
as the area selection is no longer real time (or one needs to do
2 successive crops to first reduce the image size).

-- Package-specific info:
ImageMagick program version
---------------------------
animate:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
compare:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
convert:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
composite:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
conjure:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
display:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
identify:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
import:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
mogrify:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
montage:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
stream:  ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'stable-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 5.2.0-2-amd64 (SMP w/8 CPU cores)
Locale: LANG=POSIX, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=POSIX (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages imagemagick-6.q16 depends on:
ii  hicolor-icon-theme     0.17-2
ii  libc6                  2.29-1
ii  libmagickcore-6.q16-6  8:6.9.10.23+dfsg-2.1+b1
ii  libmagickwand-6.q16-6  8:6.9.10.23+dfsg-2.1+b1

Versions of packages imagemagick-6.q16 recommends:
ii  ghostscript                  9.28~~rc2~dfsg-1
ii  libmagickcore-6.q16-6-extra  8:6.9.10.23+dfsg-2.1+b1
ii  netpbm                       2:10.0-15.3+b2

Versions of packages imagemagick-6.q16 suggests:
pn  autotrace                            <none>
ii  cups-bsd [lpr]                       2.3.0-3
ii  curl                                 7.65.3-1
pn  enscript                             <none>
ii  ffmpeg                               7:4.1.4-1+b2
ii  fig2dev [transfig]                   1:3.2.7a-7
ii  gimp                                 2.10.8-2+b1
ii  gnuplot-qt [gnuplot]                 5.2.7+dfsg1-3
pn  grads                                <none>
pn  graphviz                             <none>
ii  groff-base                           1.22.4-3
pn  hp2xx                                <none>
pn  html2ps                              <none>
ii  imagemagick-6-doc [imagemagick-doc]  8:6.9.10.23+dfsg-2.1
ii  libwmf-bin                           0.2.8.4-14
ii  mplayer                              2:1.3.0-8+b4
pn  povray                               <none>
pn  radiance                             <none>
ii  sane-utils                           1.0.27-3.2
ii  texlive-binaries [texlive-base-bin]  2019.20190605.51237-2
pn  ufraw-batch                          <none>
ii  xdg-utils                            1.1.3-1

-- no debconf information