I am running a stereo calibration after calibrating each camera independently. When running the stereo calibrate if I leave the chessboard pattern visible to the two cameras relatively close and not moving it then the stereo calibration works. Moving farther away also works but if the calibration board is moved around it will typically fail with an assertion error:
OpenCV Error: Assertion failed (nimages > 0 && nimages == (int)imagePoints1.l() && (!imgPtMat2 || nimages == (int)imagePoints2.total())) in unknown func, file ......\src\opencv\modules\calib3d\src\calibration.cpp,line 3168
I assume the data passed into stereoCalibrate() is correct since it works when the calibration pattern is not moved. Why would moving the calibration pattern is moved around?