display flickers

[broucaries]

According to Petr Gajdos <pgajdos@suse.cz>:

i,

I am experiencing a display (ImageMagick-6.5.7.9) flickering when
I open with it some images. Sometimes it starts to flicker
immediatelly, sometimes only after reducing the size to one half.

I am attaching two files, which enable this weird behaviour (without
resizing).

Important is, that this behaviour arise when running icewm or fluxbox.
I haven't met it in gnome for example and as far as I know, iteraction
with KDE is without this issue too (but I didn't tried it).

Look:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=561979
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=545175
https://bugzilla.novell.com/show_bug.cgi?id=530871

Thanks for your great work and have nice Christmas!

Petr

[fmw42]

I cannot find any images in your post to test. But my experience has been that the X11 display flickers when the image has an alpha channel. Remove the alpha channel and it does not flicker. (Mac OSX Tiger)

[broucaries]

See the debian bug for image example.

[fmw42]

I have looked at both debian reports above and still see no image or link to that image. Sorry I don't read these kinds of things well. So why don't you just put a direct link to the offending image.

[el_supremo]

Both of the sample images (yast.png and fuzzy-magick.png) have an alpha channel so Fred's suggested fix should work.

Pete

[fmw42]

el_supremo,

thanks for locating those images. I missed them completely after looking several times.

you are right in that they have transparency and that was my point above as you suggest. I don't know how to fix the X11 display to avoid flicker when the images have transparency, except to remove the transparency. Anyone who knows what to do, please let us know. Perhaps someone should write a bug report to the X11 people.

Fred

[broucaries]

How can we get the proof it is a X problem ?

Regards

Bastien

[magick]

We do see a flickering problem under Mac OS X with transparent images but on our various Linux boxes we do not see it (we used the test images). Unfortunately we do not have any Debian instances. Perhaps if we fix the problem on the Mac it will fix it under Debian as well. We'll need time to investigate.

[tri1976]

I'm using ArchLinux, kernel 2.6.32, imagemagick 6.5.9-0. I still see flickering transparent png image with display

[P2O2]

Debian kernel 2.6.26-2-amd64

IM version prior to present one (6.5.9-7) flickered when an image was decreased in size but not when increased. With the newest version the flicker effect has stopped.

Regards

[fmw42]

IM 6.5.9-7 Q16 Mac OSX Tiger

Display of transparent png images no longer flickers when I do:

display logo2t.png

but the background is transparent and you can see the other windows behind it. Perhaps it might be better to have a checkerboard behind it as is currently done by using

convert logo2t.png show:

I tried

display -texture checkerboard: logo2t.png

but the checkerboard did not show up for the background texture

[magick]

We cannot reproduce the problem. When we display a transparent image we get a checker-board background unless we add the -immutable option.

[fmw42]

tried again in IM 6.5.9-8 Q16 Mac OSX Tiger and get the same bad results. Here is the image I was using:

[magick]

Works fine for us under Linux. When we get a chance we'll check under Mac OS X.

[P2O2]

Perhaps this msgs from my problem (see
FAIL: tests/validate-formats-on-disk.sh (exit: 139)
viewtopic.php?f=3&t=15600)

will help:

Code: Select all

With:
./configure --with-x --with-windows-font-dir=/usr/share/fonts/truetype/msttcorefonts --with-gslib=yes

and the messages:
(.....)
oders/jpeg.c: In function ‘WriteJPEGImage’:
coders/jpeg.c:1632: warning: argument ‘image’ might be clobbered by ‘longjmp’ or ‘vfork’
  CC     coders/magick_libMagickCore_la-png.lo
coders/png.c: In function ‘ReadOnePNGImage’:
coders/png.c:1674: warning: variable ‘image’ might be clobbered by ‘longjmp’ or ‘vfork’
coders/png.c:1702: warning: variable ‘png_pixels’ might be clobbered by ‘longjmp’ or ‘vfork’
coders/png.c: In function ‘WriteOnePNGImage’:
coders/png.c:6288: warning: variable ‘image_matte’ might be clobbered by ‘longjmp’ or ‘vfork’
coders/png.c:6329: warning: variable ‘old_bit_depth’ might be clobbered by ‘longjmp’ or ‘vfork’
coders/png.c:6272: warning: argument ‘image’ might be clobbered by ‘longjmp’ or ‘vfork’
  CC     coders/magick_libMagickCore_la-ept.lo
  CC     coders/magick_libMagickCore_la-tiff.lo
(.....)
ltdl/ltdl.c: In function ‘load_deplibs’:
ltdl/ltdl.c:801: warning: unused parameter ‘deplibs’
ltdl/ltdl.c: In function ‘try_dlopen’:
ltdl/ltdl.c:1268: warning: the address of ‘libext’ will always evaluate as ‘true’
  CC     ltdl/ltdl_libltdlc_la-slist.lo
  CC     ltdl/loaders/dlopen.lo
  CCLD   ltdl/dlopen.la
  CC     ltdl/lt__strl.lo
(.....)
wand/convert.c: In function ‘ConvertImageCommand’:
wand/convert.c:1036: warning: unused variable ‘token’
  CC     wand/wand_libMagickWand_la-deprecate.lo
wand/deprecate.c: In function ‘MagickColorFloodfillImage’:
wand/deprecate.c:363: warning: ‘ColorFloodfillImage’ is deprecated (declared at ./magick/deprecate.h:162)
wand/deprecate.c: In function ‘MagickFlattenImages’:
wand/deprecate.c:464: warning: ‘FlattenImages’ is deprecated (declared at ./magick/deprecate.h:123)
wand/deprecate.c: In function ‘MagickMapImage’:
wand/deprecate.c:788: warning: ‘MapImage’ is deprecated (declared at ./magick/deprecate.h:181)
wand/deprecate.c: In function ‘MagickMatteFloodfillImage’:
wand/deprecate.c:860: warning: ‘MatteFloodfillImage’ is deprecated (declared at ./magick/deprecate.h:185)
wand/deprecate.c: In function ‘MagickMosaicImages’:
wand/deprecate.c:904: warning: ‘MosaicImages’ is deprecated (declared at ./magick/deprecate.h:124)
wand/deprecate.c: In function ‘MagickOpaqueImage’:
wand/deprecate.c:950: warning: ‘MagickPaintOpaqueImage’ is deprecated (declared at ./wand/deprecate.h:74)
wand/deprecate.c: In function ‘MagickPaintOpaqueImage’:
wand/deprecate.c:1051: warning: ‘MagickPaintOpaqueImageChannel’ is deprecated (declared at ./wand/deprecate.h:76)
wand/deprecate.c: In function ‘MagickTransparentImage’:
wand/deprecate.c:1257: warning: ‘MagickPaintTransparentImage’ is deprecated (declared at wand/deprecate.c:1105)
  CC     wand/wand_libMagickWand_la-display.lo
  CC     wand/wand_libMagickWand_la-drawing-wand.lo
(.....)

the IM 6.5.9-7 fails test:
(.....)
  CCLD   wand/wandtest
make[2]: Leaving directory `/home/pp/data/compile/ImageMagick-6.5.9-7'
make  check-TESTS check-local
make[2]: Entering directory `/home/pp/data/compile/ImageMagick-6.5.9-7'
make[3]: Entering directory `/home/pp/data/compile/ImageMagick-6.5.9-7'
PASS: tests/validate-compare.sh
PASS: tests/validate-composite.sh
PASS: tests/validate-convert.sh
FAIL: tests/validate-formats-on-disk.sh
FAIL: tests/validate-formats-in-memory.sh
PASS: tests/validate-identify.sh
(.....)
PASS: wand/wandtest.sh
===========================================
2 of 47 tests failed
See ./test-suite.log
Please report to http://www.imagemagick.org
===========================================
make[3]: *** [test-suite.log] Error 1
make[3]: Leaving directory `/home/pp/data/compile/ImageMagick-6.5.9-7'
make[2]: *** [check-TESTS] Error 2
make[2]: Leaving directory `/home/pp/data/compile/ImageMagick-6.5.9-7'
make[1]: *** [check-am] Error 2
make[1]: Leaving directory `/home/pp/data/compile/ImageMagick-6.5.9-7'
make: *** [check] Error 2
$

Most of these statements were generated during compilation of former IM sources prior to 6.5.9-7 which brought flickering during decreasing size of imgs. Now the flicker stopped but to check it thoroughly I have to have working IM. But this is yet to happen.
I use Debian 5.0.4 with fglrx driver for ATI Radeon 4200 embedded GPU.

Regards