Hi all,<div><br></div><div>I am writing something using nodelet to process images from kinect, using openni_nodelet under openni_camera package to retrieve images from kinect, and my nodelet to subscribe it.</div><div><br>
</div><div>I wrote a launch file to start the nodelet_mgr, openni_nodelet and my nodelet, and I use openCV windows to display images got from openni_nodelet, I wrote something like this as the callback:</div><div><br></div>
<div>onRGBDImage(const pcl::PointCloud&lt;pcl::PointXYZRGB&gt;::ConstPtr&amp; cloud_msg)</div><div>{</div><div>    cv::Mat mat_rgb;</div><div>    // Convert from cloud_msg to cv::Mat</div><div>    //...</div><div>    cv::imshow(mat_rgb);</div>
<div>    cv::waitKey(5);</div><div>}</div><div><br></div><div>But when I start all nodes using the launch file, sometimes it can display images properly, but sometimes it cannot, and the openCV window goes grey(Not responding because no call to cv::waitKey() for some time)</div>
<div><br></div><div>I don&#39;t know whether there exists some rules that I should follow when using nodelet, e.g. subscribers should start after publishers? How can I make it work every time?</div><div><br></div><div>I am using electric under ubuntu 10.10.</div>
<div><br></div><div>Thanks for any help.</div><div><br></div><div>P.S. Here is my launch file:</div><div><br></div><div><div>&lt;launch&gt;</div><div>  &lt;node pkg=&quot;nodelet&quot; type=&quot;nodelet&quot; name=&quot;nodelet_mgr&quot;  args=&quot;manager&quot; output=&quot;screen&quot;/&gt;</div>
<div><br></div><div>  &lt;!-- openni_camera nodelet --&gt;</div><div>  &lt;node pkg=&quot;nodelet&quot; type=&quot;nodelet&quot; name=&quot;openni_camera&quot; args=&quot;load openni_camera/OpenNINodelet nodelet_mgr&quot;&gt;</div>
<div>    &lt;param name=&quot;device_id&quot; value=&quot;#1&quot;/&gt; &lt;!-- this line uses first enumerated device --&gt;</div><div>    &lt;rosparam command=&quot;load&quot; file=&quot;$(find openni_camera)/info/openni_params.yaml&quot; /&gt;</div>
<div>    &lt;param name=&quot;rgb_frame_id&quot; value=&quot;/openni_rgb_optical_frame&quot; /&gt;</div><div>    &lt;param name=&quot;depth_frame_id&quot; value=&quot;/openni_depth_optical_frame&quot; /&gt;</div><div>    &lt;param name=&quot;depth_registration&quot; value=&quot;true&quot; /&gt;</div>
<div>    &lt;param name=&quot;image_mode&quot; value=&quot;2&quot; /&gt;</div><div>    &lt;param name=&quot;depth_mode&quot; value=&quot;2&quot; /&gt;</div><div>    &lt;param name=&quot;debayering&quot; value=&quot;2&quot; /&gt;</div>
<div>    &lt;param name=&quot;depth_time_offset&quot; value=&quot;0&quot; /&gt;</div><div>    &lt;param name=&quot;image_time_offset&quot; value=&quot;0&quot; /&gt;</div><div>  &lt;/node&gt;</div><div>  &lt;include file=&quot;$(find openni_camera)/launch/kinect_frames.launch&quot;/&gt;</div>
<div><br></div><div>  &lt;node pkg=&quot;nodelet&quot; type=&quot;nodelet&quot; name=&quot;TabletopObj&quot; args=&quot;load vision/TableTopObjNodelet nodelet_mgr&quot; output=&quot;screen&quot;&gt;</div><div>  &lt;/node&gt;</div>
<div>&lt;/launch&gt;</div><div><br></div>-- <br>Regards<br><br>University of Science and Technology of China<br>School of Computer Science and Technology<div>Multi-Agent System Lab<br><br>K.Chen</div><br>
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