cvUndistort2 () and cvRemap () crash

Question

I was doing example 11-1 of \"Learning OpenCV\" by Bradski. Unfortunately the given example doesn\'t work on my computer.

The program is supposed to calibrate camera

Answer 1

The problem is that cvUndistort2 and cvRemap receive 8bit images only. Hence, in order to process color images, one must use cvSplit and cvMerge:

   IplImage *r = cvCreateImage(cvGetSize(image),8,1);//subpixel
   IplImage *g = cvCreateImage(cvGetSize(image),8,1);//subpixel
   IplImage *b = cvCreateImage(cvGetSize(image),8,1);//subpixel

   while(image) {
       cvShowImage( "Calibration", image ); // Show raw image
       //cvCvtColor(image, gray_image, CV_BGR2GRAY);
       cvSplit(image, r,g,b, NULL);

       cvRemap( r, r, mapx, mapy ); // Undistort image
       cvRemap( g, g, mapx, mapy ); // Undistort image
       cvRemap( b, b, mapx, mapy ); // Undistort image

       cvMerge(r,g,b, NULL, image);
   cvShowImage( "Undistort", image); // Show corrected image

Answer 2

try

cvRemap( t, image, mapx, mapy ); 
cvUndistort2(t ,image , intrinsic, distortion);

instead of

cvRemap( image, t, mapx, mapy ); // Undistort image
       cvUndistort2(image, t, intrinsic, distortion);