I am trying to install opencv in my centOs system. When I am giving the below command it is showing the information below :


[root@asterisk1 opencv-rpm]# rpm -ivh opencv-1.0.0-1.el4.rf.i386.rpm --nodeps
warning: opencv-1.0.0-1.el4.rf.i386.rpm: V3 DSA signature: NOKEY, key ID 6b8d79e6
Preparing... ########################################### [100%]
package opencv-1.0.0-1.el4.rf is already installed


but when I am querying whether it is installed or not by the command below it is showing this information:

[root@asterisk1 opencv-rpm]# rpm -q opencv-1.0.0-1.el4.rf.i386.rpm
package opencv-1.0.0-1.el4.rf.i386.rpm is not installed


so I am not understanding what exactly is happening. So can you figure out what is the problem.

After figuring out the problem can you also tell me the commands to run the opencv application.

Thanks to you in advance.

This tells you the rpm is already installed
you probably want to do rpm -qa| grep opencv to confirm whether a package is installed, it will return all instances and appropriate versions

then http://opencv.willowgarage.com/wiki/ should help regarding usage

disclaimer: i do not know opencv

'rpm -ql opencv' prints a file list :
/usr/bin/opencv-createsamples
/usr/bin/opencv-haartraining
/usr/bin/opencv-performance
/usr/lib/libcv.so.1
etc. etc.
The documentation will tell ( hopefully ) how to use
the opencv program. ( See the link, # 2, thierrys.)

" opencv-1.0.0-1.el4.rf.i386.rpm " is a 'rpmforge' package
and will usually be installed with 'yum install opencv'
if you have the rpmforge repository in /etc/yum.repos.d/
( http://dag.wieers.com/rpm/FAQ.php#B )
.....

The "rpm database package id" is not
'opencv-1.0.0-1.el4.rf.i386.rpm' but just 'opencv' or 'opencv-1.0.0-1.el5.rf'.
.....