#974750 imagemagick-6.q16: Convert to .tga (Targa) now flips image upside-down

Package:
imagemagick-6.q16
Source:
imagemagick
Description:
image manipulation programs -- quantum depth Q16
Submitter:
Matija Nalis
Date:
2024-04-05 14:54:15 UTC
Severity:
normal
#974750#5
Date:
2020-11-14 16:37:42 UTC
From:
To:
Dear Maintainer,

Converting to .tga (Targa) format now (Unstable) flips image upside-down.

It worked fine in Buster version (imagemagick 8:6.9.10.23+dfsg-21+deb10u1)
and it still works fine with graphicsmagick version in Unstable
(graphicsmagick 1.4+really1.3.35+hg16348-1+b1). So this is regression.

Resulting .tga image created by Sid version of imagemagick
8:6.9.11.24+dfsg-1+b2 is consistently vertially flipped when viewed in all
viewers (gimp, xzgv, xli, mirage, and even imagemagick's own display(1))

One can kludge around by using "convert-im6 -flip" to get correct image, but
it is wrong behaviour.

sid% convert-im6.q16 Graphics_Assets/intro5.png /tmp/imagemagick_sid.tga
sid% gm convert Graphics_Assets/intro5.png /tmp/graphicsmagick_sid.tga
sid% convert-im6 -flip Graphics_Assets/intro5.png /tmp/imagemagick_flip_sid.tga
sid% md5sum /tmp/*_sid.tga
81d1f1a2c481958c5af09c3985615ed0  /tmp/graphicsmagick_sid.tga
81d1f1a2c481958c5af09c3985615ed0  /tmp/imagemagick_flip_sid.tga
d948d272cbb2ab8230ee0b185414e6c6  /tmp/imagemagick_sid.tga

buster% convert-im6.q16 Graphics_Assets/intro5.png /tmp/imagemagick_buster.tga
buster% md5sum /tmp/imagemagick_buster.tga
81d1f1a2c481958c5af09c3985615ed0  /tmp/imagemagick_buster.tga

It happens with any source file; I've tried with several .png and .jpg files
as source, for example /usr/share/desktop-base/spacefun-theme/login/sddm-preview.jpg
or /usr/lib/libreoffice/share/template/wizard/bitmap/euro_2.png

Bug only happens when converting to .tga (converting to png/jpg/tiff works
normally)

Of course, the nature of bug is such that if you convert from .png to .tga,
and then back from .tga to .png, the seconds .png will again look correct,
as bug happened twice and thus fixed itself again!

#974750#10
Date:
2024-04-05 14:49:52 UTC
From:
To: