jpg file after convert rotate corrupted.

[chenlq]

I need rotate a jpg image by covert .
using command like:
convert -rotate -90 img.jpg nimg.jpg
The new image 'nimg.jpg' is rotated but corrupted with many vertical line on surface.

$ convert -version
Version: ImageMagick 6.4.6 2008-12-26 Q16 OpenMP
$ uname -a
Linux xx.com 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:19 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux

before:


after:

[chenlq]

sorry. It'is already resolved in
viewtopic.php?f=1&t=12745