OpenCV : LinearPolar transformations | Unwrap fisheye image to Panorama

       In this post I am demonstarting how LinearPolar transform can used to unwrap 360 degree image to panoramic image.

    Basically we have to load the image and input to LinearPolar function, the function have the arguments

 src – Source image
 dst – Destination image.
 center – The transformation center;
 maxRadius – The radius of the bounding circle to transform.
 flags – INTER_CUBIC, WARP_FILL_OUTLIERS, WARP_INVERSE_MAP etc..

C++ Code

    Mat src = imread("pan9.jpg", 1);
    Mat linearPolarMat;
    linearPolar(src,linearPolarMat,Point(src.cols/2, src.rows/2),src.cols/2,INTER_CUBIC);

    //Rotate 90 degree
    transpose(linearPolarMat, linearPolarMat);
    flip(linearPolarMat, linearPolarMat,0);

    imshow("linearPolar", linearPolarMat);
    imshow("src", src);
    waitKey();

Result

Source

linearPolar Transform

Source

linearPolar Transform

Here is another post related to unwrap fisheye image Unwrap 360 degree image using OpenCV | Converting fisheye image into panorama image