Learning OpenCV

Putting Calibration All Together

OK, now it's time to put all of this together in an example. We'll present a program that performs the following tasks: it looks for chessboards of the dimensions that the user specified, grabs as many full images (i.e., those in which it can find all the chessboard corners) as the user requested, and computes the camera intrinsics and distortion parameters. Finally, the program enters a display mode whereby an undistorted version of the camera image can be viewed; see Example 11-1. When using this algorithm, you'll want to substantially change the chessboard views between successful captures. Otherwise, the matrices of points used to solve for calibration parameters may form an ill-conditioned (rank deficient) matrix and you will end up with either a bad solution or no solution at all.

Example 11-1. Reading a chessboard's width and height, reading and collecting the requested number of views, and calibrating the camera

// calib.cpp // Calling convention: // calib board_w board_h number_of_views // // Hit 'p' to pause/unpause, ESC to quit // #include <cv.h> #include <highgui.h> #include <stdio.h> #include <stdlib.h> int n_boards = 0; //Will be set by input list const int board_dt = 20; //Wait 20 frames per chessboard view int board_w; int board_h; int main(int argc, char* argv[]) { if(argc != 4){ printf("ERROR: Wrong number of input parameters\n"); return -1; } board_w = atoi(argv[1]); board_h = atoi(argv[2]); n_boards = atoi(argv[3]); int board_n ...