longervision/examples_opencv

Some Examples in OpenCV

OpenCV_Examples

Some Examples in OpenCV

examples_opencv's Issues

why the calibrated intrinsic matrix drifts a lot from the true value?

Hello there,
I was using this demo to calibrating my own camera while the result showed a unacceptable drifts from the truth.
OpenCV version 3.2.0
Python version 3.6.7
The input images series is like below:

and the corresponding detected images is

There is one problem I am not that sure is, the asymmetric calibration target I used has a differently distance between the columns and rows which could be seen clearly from my code
longerCalibrate.txt

Finally, the result of intrinsic calibration is

camera_matrix:

• [451.6701112652139, 0.0, 777.2304056394676]
• [0.0, 469.37232191132745, 321.2437268938009]
• [0.0, 0.0, 1.0]
  dist_coeff:
• [-0.1705178885286108, 0.013773972732487686, 0.0012506566857040959, 0.004203751684462792,
  0.006202670677996154]

but actually, the intrinsic matrix should be
9.543190920000000000e+02 0.000000000000000000e+00 6.399660030000000000e+02 0.000000000000000000e+00 9.543190920000000000e+02 3.634058530000000000e+02 0.000000000000000000e+00 0.000000000000000000e+00 1.000000000000000000e+00

this is true because the resolution of these pictures is 1280x720, more reasonable

So the question is, is there anything wrong with my code or is it a kernel problem of the opencv function?

OpenCV Error: Assertion failed ((K.depth() == CV_32F || K.depth() == CV_64F) && (D.depth() == CV_32F || D.depth() == CV_64F))

Hi,

I tried your project and it is interesting. But I find this error:
OpenCV Error: Assertion failed ((K.depth() == CV_32F || K.depth() == CV_64F) && (D.depth() == CV_32F || D.depth() == CV_64F))
Do you know any solution to fix it?

Thanks,
Gergely