Redistort the image / undo image rectification

Question

I am using the omnidirectional camera module in OpenCV to find depth maps from input stereo images. I am getting the disparity maps like this:

However I want to redistort this particular image so that it looks like the original input image like this:

That is it should look like the camera's original field of view. Can anyone tell me how to re-distort a particular image?

Answer 1

If you have your camera intrinsics from calibration you can try to use this OpenCV function:

cv::omnidir::undistortImage()

using distortion parameters (k1*, k2, p1, p2) with k1* = -k1 (it is a wild shot, I have never tried it).

See the note on radial distortion types in the Camera Calibration and 3D Reconstruction module:

https://docs.opencv.org/2.4/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html