// Simple radial correction demonstration.
// Uses just one parameter
//
// John Robinson 2004.

#include "picture.h"
int main(int argc, char *argv[]) {
	colour_picture in(argc, argv, 480, 640, 80);	
	// Set up sequence processing. The paramters 480, 640 are the
	// size of the camera image if there are no arguments.
	// Parameter 80 is for large border because we'll be doing geometric
	// transforms that go into the border area.
	double corr;
	parampic corrpic(-0.1,0.1,0,"Radial parameter");
	in.show("Input");
	colour_picture out(in);
	out.show("Output");
	const int origy(out.nrows()/2);
	const int origx(out.ncols()/2);
	double oldx, oldy;
	while(!in.closerequested() && !out.closerequested()) {
		in.next();
		in.dc_pad(); // Extend the values on the pictures borders out.
		in.reshow();
		corrpic.X(corr);
		for (int newy = 0; newy < out.nrows(); newy++)
		for (int newx = 0; newx < out.ncols(); newx++) {
			int y = newy - origy;
			int x = newx - origx;
			double rsquared = (double)y*y + x*x;
			double offset = corr*rsquared/(double)(origx*origy);
			oldy = y - offset*y + origy;
			oldx = x - offset*x + origx;
			out.map(newx,newy,in,oldx,oldy,0);
			}
		out.reshow();
		}
	return 1;
	}