2014-11-25 02:55:15 -0500 commented question OpenCV 2.4.9 + Asus Xtion Pro Live When you built opencv, did you set the -WITH_OPENNI flag? I had a similar problem when I didn't know that. If not you have to build it again with the right flags set. It could also be a problem with your openni/primesense version. But since you can launch the viewer that shouldn't be it. 2014-11-25 02:26:40 -0500 asked a question Stereo Vision With Fisheye and FOV camera Hi, I have two stereo cameras with different focal length and a baseline of roughly 10cm. I performed an in- and extrinsic calibration using a tool based on Bouguets algorithm under http://www.vision.caltech.edu/bouguetj/calib_doc/ Here are the output I got: Intrinsic parameters of left camera (HD): Focal Length: fc_left = [ 941.65838 941.99357 ] � [ 1.19499 1.55626 ] Principal point: cc_left = [ 643.69533 348.60145 ] � [ 1.28309 1.52477 ] Skew: alpha_c_left = [ 0.00000 ] � [ 0.00000 ] => angle of pixel axes = 90.00000 � 0.00000 degrees Distortion: kc_left = [ 0.17235 -0.30426 0.00261 0.00016 0.00000 ] � [ 0.00382 0.00795 0.00066 0.00056 0.00000 ] Pixel error: err = [ 0.14001 0.15865 ]  Intrinsic parameters of right camera (Wide Angle): Focal Length: fc_right = [ 275.62703 275.32800 ] � [ 1.56095 1.91438 ] Principal point: cc_right = [ 322.41626 234.36411 ] � [ 2.46595 2.00803 ] Skew: alpha_c_right = [ 0.00000 ] � [ 0.00000 ] => angle of pixel axes = 90.00000 � 0.00000 degrees Distortion: kc_right = [ -0.30762 0.11325 -0.00185 -0.00070 0.00000 ] � [ 0.00756 0.00923 0.00092 0.00115 0.00000 ]  Extrinsic parameters (position of right camera wrt left camera): Rotation vector: om = [ -0.04394 0.00216 -0.00449 ]  Translation vector:  T = [ -108.66272 -0.94249 -6.31156 ].  I then put the data into opencvs functions ->stereoRectify( ..., CALIB_USE_INTRINSIC_GUESS, -1 , ... ) ->initUndistortRectifyMap() -> remap(... INNTER_LINEAR) In case you wonder why the fisheye image is still so much distorted at the outer parts, that is because I only calibrated the common viewing area of the two cameras. to get the rectified version of left and right hand side images. Here is what the output looks like: When I feed the rectified images then into the Stereo block matcher (StereoBM()) I do do not manage to get a good depth map from that. Also with other images I fail getting good results with this setup. Therefore my questions are: What can I expect from the rectification? Is that a good result or should the images be aligned with pixel accuracy over the whole scene? What can I do to get good results for my stereo application - or what are the reasons for the bad performance of my code (Is it possible to combine the Fisheye camera and a "normal" field of view camera in a stereo setup with good results)? Due to the difference in the focal length and the image size, I can only use a small part of the fisheye image. Any Ideas how I could make the best out of it (e.g. Interpolation with data from right hand side image?)? Cheers! 2013-11-23 17:44:08 -0500 asked a question OpenCV + QTCreator -> cannot read file from hard disk? Hi, I wanted to switch from Code::Blocks to QTCreator after formatting my hard disk. But when I want to use the code I was compiling before without any errors, I now get an errormessage /usr/include/opencv2/core/operations.hpp:2794: error: no matching function for call to 'read(cv::FileNodeIterator, std::vector&)'  when I execute the following: std::vector key2 cv::FileStorage fs("keypoint.yml", cv::FileStorage::READ); cv::FileNode kptFileNode1 = fs["Class1"]; cv::read( kptFileNode1, key2 ); fs.release();  The error is related to the type of the vector, but why did it work before (in Code::Blocks) and how can I fix this? I'm using ubuntu 12.04 with opencv-2.4.7 and Qt Creator 2.4.1 . Thanks for helping.