xwdtopnm generates bad pnm files

[Penelope Fudd]

I'm trying to capture the screen to a png file, with the following command:

xwd -root -display :0 | xwdtopnm | pnmtopng > file.png

The output file is a valid png file, but it's a garbled picture.

By doing the following diagnostic steps, xwdtopnm was determined to be the problem:

xwd -root -display :0 > test.xwd ; gimp test.xwd ===> picture looks good
xwdtopnm < test.xwd > test.pnm ; gimp test.pnm ===> gimp reports "PNM Image Message: Unsupported maximum value."
pnmtopng < test.pnm > test.png ; gimp test.png ===> gimp loads a garbled picture

file test.xwd ===> file.xwd: XWD X Window Dump image data, "xwdump", 3840x1080x24

pnmtoxwd < test.pnm > test2.xwd ; gimp test2.xwd ===> gimp loads a garbled picture

Hopefully you can fix the glitch in xwdtopnm easily!

Thanks!

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: netpbm 2:10.0-15
ProcVersionSignature: Ubuntu 3.8.0-44.66~precise1-generic 3.8.13.25
Uname: Linux 3.8.0-44-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.7
Architecture: amd64
Date: Thu Oct 9 11:51:37 2014
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 SHELL=/bin/bash
SourcePackage: netpbm-free
UpgradeStatus: No upgrade log present (probably fresh install)

[linuxball (linuxball)]

It is sad but true: More than two years later in netpbm (2:10.0-15.3) of Ubuntu 16.04.1 LTS the bug is still not fixed :-(

Fortunately, there is another tool set (ImageMagick) which has a working conversion tool (convert). So one can convert xwd output to file.png by executing:

xwd -root -display :0 | convert xwd:- file.png

I attached file "test.xwd" which shows the bug of xwdtopnm

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[linuxball (linuxball)]

Just for completeness I tested xwdtopnm of netpbm (2:10.0-15ubuntu2) in Ubuntu 14.04.5 LTS and I confirm that it suffers from this bug, too.