Hi community,

I'm trying to use the image_pipeline-package to realize a stereovisual system with ros and opencv.

When I use the node for calibration of one usb-camera I get an error every time I put the chessboard (8x6) in front of the camera and the node freezes. I googled the problem and found two ros-questions similar to my problem. One answer was to install a 64-bit version of ubuntu, and the second one was to remove opencv-files from the ros-libraries and install the original opencv-files instead. Now I'm wondering if theres another way to get rid of my problem and where it comes from. I attached the output of my console below my request.

Part two of my problem: When I try to use the stereocamreacalibraton the node tells me that all parameters are there, but then there doesn't pop up the gui.

I'm currently using Ubuntu 12.04 with ros-hydro-installation.

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++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ rosrun cameracalibration cameracalibrator.py --size 8x6 --square 0.0242 image:=/stereo/left/imageraw camera:=/stereo/left Waiting for service /stereo/left/setcamerainfo ... OK *** Added sample 1, px = 0.931, py = 0.486, psize = 0.349, skew = 0.186 OpenCV Error: Assertion failed (blockSize % 2 == 1 && blockSize > 1) in adaptiveThreshold, file /tmp/buildd/ros-hydro-opencv2-2.4.6-1precise-20130919-0139/modules/imgproc/src/thresh.cpp, line 797 Exception in thread Thread-3: Traceback (most recent call last): File "/usr/lib/python2.7/threading.py", line 551, in _bootstrapinner self.run() File "/home/faps/catkinws/src/imagepipeline/cameracalibration/nodes/cameracalibrator.py", line 68, in run self.function(m) File "/home/faps/catkinws/src/imagepipeline/cameracalibration/nodes/cameracalibrator.py", line 134, in handlemonocular drawable = self.c.handlemsg(msg) File "/home/faps/catkinws/src/imagepipeline/cameracalibration/src/cameracalibration/calibrator.py", line 740, in handlemsg scribmono, corners, downsampledcorners, board, (xscale, yscale) = self.downsampleanddetect(gray) File "/home/faps/catkinws/src/imagepipeline/cameracalibration/src/cameracalibration/calibrator.py", line 410, in downsampleanddetect (ok, downsampledcorners, board) = self.getcorners(scrib, refine = True) File "/home/faps/catkinws/src/imagepipeline/cameracalibration/src/cameracalibration/calibrator.py", line 378, in getcorners (ok, corners) = _getcorners(img, b, refine) File "/home/faps/catkinws/src/imagepipeline/cameracalibration/src/cameracalibration/calibrator.py", line 156, in getcorners (ok, corners) = cv.FindChessboardCorners(mono, (board.ncols, board.nrows), cv.CVCALIBCBADAPTIVETHRESH | cv.CVCALIBCBNORMALIZEIMAGE | cv2.CALIBCBFAST_CHECK) error: blockSize % 2 == 1 && blockSize > 1

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