[ros-users] Digital Camera 1394 in ROS?

[Jack O'Quin]

On Fri, Mar 19, 2010 at 5:23 AM, Peshala <peshala at hlab.iis.u-tokyo.ac.jp> wrote:
>
>> The current version publishes /<nodename>/camera/image_raw for
>> compatibility with the other camera drivers. It should display in
>> rviz, although rviz will complain:
>>
>>   Status error
>>   CameraInfo/P resulted in an invalid position calculation (nans or
>> infs)

>> You can update svn and try it again. To find the correct topic name in
>> rviz. click on the [...] box to the right of the Image Topic field
>> under Camera.

> Jack,
> Thank you very much for your reply.
>
> Here is my current status.
> I tried using both camera1394 and cameradc1394 nodes. But still rviz
> does not display any images.
> When camera1394 was run, rostopic echo /camera1394/image does not
> display anything. So I assume there is no way rviz can display any
> images.

That is not the topic name it should be publishing. Try "rostopic
list", it should show a topic name like /camera1394/camera/image_raw
(assuming "camera1394" is the node name).

Try viewing that with image_view:

 $ rosrun image_view image_view image:=/camera1394/camera/image_raw

If that works, your camera is responding.

> When cameradc1394 was run, rostopic echo /camera1394/image display data.
> But still, as you mentioned, I could not find /camera/image_raw but
> instead the topics
> -Image(sensor_msgs/Image)
> -image(sensor_msgs/Image)
> -OriginalImage(sensor_msgs/Image) are there.
> rviz gives the following warning for this case.
> Discarding message from [/cameraopencv] due to empty frame_id.

Most of the compatibility issues with camera1394 probably affect
cameradc1394 similarly. Saving and restoring calibration data is the
main problem right now. The Willow Garage cameras have non-volatile
memory where they can save CameraInfo on the device. That does not
work for 1394 cameras.

The frame_id issue is probably unique to cameradc1394. It needs to be
set in the Header of the sensor_msgs/Image (and sensor_msg/CameraInfo)
messages. I don't think cameradc1394 is publishing CameraInfo yet. If
not, rviz refuses to show the image.

> Should I calibrate the camera first?
> I did the svn update but still something is missing.

Calibrating the camera will not help much until I get some code
written to save and restore the calibration data. There has been some
recent discussion about the best way to do that.
-- 
 joq