Vincent_V's profile - activity

Not sure if it could help but I just had the same issue while upgrading from Ubuntu 18.04 and Melodic to 20.04 and Noeti

Not sure if it could help but I just had the same issue while upgrading from Ubuntu 18.04 and Melodic to 20.04 and Noeti

Found it!

In order to use rxbag (much more efficient than the extract_image node => did not extract all the images of my bags files) you have to :

1°) select with your mouse the length of your timeline (a slightly cyan color show up as you select it)

2°) play your bag file (let it run)

3°) select the view "image"

4°) click on the button on the right of the text "frame%04d.png"

5°) And here normaly pop's up an another window that offers you to save all the frames

Regards

I knew that technique but it seems that it does not extract all the images when you saved them with a specific frame rate. So if you don't recompile the all extract_images.cpp with the specific framerate it does not work well. That's why I was looking for an another solution at this problem.

Hello everyone !

I was wondering is there is any steps to follow in order to save all the frames that I put into a rosbag on my computer with rxbag.

I noticed that there is a button "save frames" when you open it with the following : "View (by type) -> sensor_msgs/Image->stereo/left/image_rect "

I'm able to "select" the frames or should I say the Timeline in the default menu of rxbag (because it's written at the bottom of the image_viewer that it "Save frames from selected region") but it seems to have no effect when I click on the "save frames" button.

any hints ?

Best regards

Hi all !

Now with my own camera driver (thanks to all of you) I'm able to run stereo_image_proc and obtain disparity and corrected images.

Now I'm facing a little problem that I'm sure was already solved.

I would like , with the stereo rectified images, to make a stereo matching in OpenCV.

How can I created a node that subscribe to 2 image topics at the same time with the same callback method that will convert the message_image to an OpenCV image with CVbridge.

I know how to convert images and do all the stuff with it thanks to this tutorial http://www.ros.org/wiki/cv_bridge/Tutorials/UsingCvBridgeToConvertBetweenROSImagesAndOpenCVImages

But I don't know how to do it with two images topics to subscribe to :)!

I did a little search within the stereo_image_proc node (with the disparity.cpp )how they manage to do that (with the camera_info too) but the on-demand option do not suit me at all. However, since my camera are not very well synchronized (I use approximate_sync because of an arduino external trigger) I 'll also need to sync these two with the ros.time and their according time stamp ! (Or at least check if they'll be approximatly synced !

So I'm asking you is there any tutorials about it ? or do you know a way to do it simply ?

Regards

Thanks

I figure out what was wrong according to my second update.

It was my driver that has something wrong.

I was setting roi.x_offset and roi.y_offset to 16 instead of 0 in order to have a 640x480 image instead of a 640x512. But I forgot that with these cameras it's done automatically by the hardware of the cameras.

Thanks for the help.

Hi,

There is two things you should try :

First : I see that you type image:/usb_cam but It should be for remapping image:=/usb_cam with the "=" !

Then I did not see what you have set for your camera since it seems that you have paste the answer of you terminal right after you camera:=/ command

So to complete your command line do a rostopic list as follow

vvittori@delos:~/ros_workspace/stereo_robust_matching$ rostopic list
/camera/camera_info
/camera/image_raw
/camera/image_raw/compressed
/camera/image_raw/compressed/parameter_descriptions
/camera/image_raw/compressed/parameter_updates
/camera/image_raw/theora
/camera/image_raw/theora/parameter_descriptions
/camera/image_raw/theora/parameter_updates
/cameraUEYE_node/parameter_descriptions
/cameraUEYE_node/parameter_updates
/rosout
/rosout_agg

and then set the command line as follow (in my exemple /camera/image_raw is my image and /camera is my camera name )

rosrun camera_calibration cameracalibrator.py --size 8x6 --square 0.108 image:=/camera/image_raw camera:=/camera

So for you it should be I gess

rosrun camera_calibration cameracalibrator.py --size 10x7 --square 0.022  image:=/usb_cam/image_raw camera:=/usb_cam

Regards

V.v

I don't know what properly set is for you ? Here is in the main post the bag file you ask . Thank you

Oh thanks Patrick I didn't notice that part in the wiki page ! I was still block at the rosnode info stereo/proc results that they give us.

Anyway I've tried what you told me with the following command line (I have change stereo_test to stereo in my launch file)

ROS_NAMESPACE=stereo rosrun stereo_image_proc stereo_image_proc __name:=PROC

and

rosrun image_view stereo_view stereo:=/stereo image:=image_rect

as written in the wiki page. Then, I did see what you told me that right after I launch the previous command it subscribed at

[ INFO] [1334565947.793592670]: Subscribing to:
    * /stereo/left/image_rect
    * /stereo/right/image_rect
    * /stereo/disparity

and yet I had the following error that occured :

OpenCV Error: Assertion failed (0 <= roi.x && 0 <= roi.width && roi.x + roi.width <= m.cols && 0 <= roi.y && 0 <= roi.height && roi.y + roi.height <= m.rows) in Mat, file /tmp/buildd/libopencv-2.3.1+svn6514+branch23/modules/core/src/matrix.cpp, line 303
OpenCV Error: Assertion failed (0 <= roi.x && 0 <= roi.width && roi.x + roi.width <= m.cols && 0 <= roi.y && 0 <= roi.height && roi.y + roi.height <= m.rows) in Mat, file /tmp/buildd/libopencv-2.3.1+svn6514+branch23/modules/core/src/matrix.cpp, line 303
terminate called after throwing an instance of 'cv::Exception'
  what():  /tmp/buildd/libopencv-2.3.1+svn6514+branch23/modules/core/src/matrix.cpp:303: error: (-215) 0 <= roi.x && 0 <= roi.width && roi.x + roi.width <= m.cols && 0 <= roi.y && 0 <= roi.height && roi.y + roi.height <= m.rows in function Mat
Aborted

Do you know what it could be ?

Thanks

Regards

V.v

It was a "test" choice but I think that it is not a big deal as long as you specified it in the ROS_NAMESPACE . I maybe wrong I'll check it !

Hi !

I had the same issue once with my Ueye camera (USB) and because my synchonisation was not that good I had to use at the end of the calibration command line the following argument:

--approximate = 0.1

Thing that you have put too in your command line. But try a different number !

If you want more information about this option see http://www.ros.org/wiki/camera_calibration at 4.1.1

Besides I don't know if it's recommended but you do not need the stereo_image_proc node to make your calibration.

regards

V.v