Hello. i have an Ubuntu 10.04 and Ros diamondback. I try to do image_transport tutorial ( http://www.ros.org/wiki/image_transport/Tutorials) i run (as here http://www.ros.org/wiki/image_transport/Tutorials/ExaminingImagePublisherSubscriber ) ------------------------------------------------------------------------------------------- alexander@alexander-laptop:~/learning_image_transport$ rosrun learning_image_transport my_publisher home/alexander/image.jpg --------------------------------------------------------------------------------------------- And i got next error: ----------------------------------------------------- OpenCV Error: Null pointer (NULL array pointer is passed) in cvGetMat, file /tmp/buildd/ros-diamondback-vision-opencv-1.4.3/debian/ros-diamondback-vision-opencv/opt/ros/diamondback/stacks/vision_opencv/opencv2/build/opencv-svn/modules/core/src/array.cpp, line 2380 terminate called after throwing an instance of 'cv::Exception' what(): /tmp/buildd/ros-diamondback-vision-opencv-1.4.3/debian/ros-diamondback-vision-opencv/opt/ros/diamondback/stacks/vision_opencv/opencv2/build/opencv-svn/modules/core/src/array.cpp:2380: error: (-27) NULL array pointer is passed in function cvGetMat Aborted -------------------------------------------------------------------------- How can i correct this situation? Thank you