Stereo calibration sample producing zoomed-out rectification

asked 2015-12-16 11:44:50 -0600

Boogaloo gravatar image

I have the stereo calibration sample working perfectly using the supplied chessboard frames, but when using my own images, that have the same VGA resolution and similar chessboard poses, the resultant rectified images are reduced to the centre area of the VGA image, i.e. the camera has zoomed out, also both are rotated 20 degrees to counterclockwise.

I suppose the R and T values from stereocalibrate are causing this, but why? My own camera-grabbed images have been made to closely match the sample images, and look almost identical.

The only obvious difference is that my chessboard is 10 x 7, and the sample's is 8 x 6 - but I did change the board parameter to 9 x 6!

I'm getting and RMS error of 0.632, Avg of 1.208

What could be causing the correctly rectified results to be scaled down, like the camera has been pulled back?

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Comments

I've just noticed that the valid region for the rectified image is wrong, it has a vertical misalignment as you can see on the screen grab: https://www.sendspace.com/file/z79c8i

Boogaloo gravatar imageBoogaloo ( 2015-12-16 13:21:06 -0600 )edit