"Access violation" when assigning matrix values

[karnavor]

Hello,

I am writing a program to estimate the fundamental matrix between two images, using OpenCV. This is a computer vision technique, but the error I am getting is something to do with memory in the program itself. I have copied the code exactly from this reliable source: http://books.google.co.uk/books?id=s...xample&f=false

Here is the code below:

int main()
{
	int point_count = 100;
	CvMat* points1;
	CvMat* points2;
	CvMat* status;
	CvMat* fundamental_matrix;

	points1 = cvCreateMat(1,point_count,CV_32FC2);
	points2 = cvCreateMat(1,point_count,CV_32FC2);
	status = cvCreateMat(1,point_count,CV_8UC1);

	/* Fill the points here … */
	for(int i = 0; i < point_count; i++ )
	{
	    points1->data.db[i*2] = 2;
	    points1->data.db[i*2+1] = 4;
	    points2->data.db[i*2] = 5;
	    points2->data.db[i*2+1] = 3;
	}

	fundamental_matrix = cvCreateMat(3,3,CV_32FC1);
	int fm_count = cvFindFundamentalMat( 
	points1,points2,fundamental_matrix,
	CV_FM_RANSAC,1.0,0.99,status );

        return 0;
}

However, when this is run, I get the following error:

"Unhandled exception at 0x0040122b in TestProgram.exe: 0xC0000005: Access violation writing location 0x0037d000."

This occurs when i = 54, at the line "points2->data.db[i*2] = 5;"

It seems to be suggesting that I don't have enough memory to make this assignment, but I have reserved enough. My "points2" matrix contains 100 elements, each of type CV_32FC2 (which represent two floating points), and thus the matrix should be able to hold 200 floating points.

Furthermore, this code is copied exactly from the source, which is a reliable text book. So, the code should run, and I am very confused as to why I am getting this error.

Thanks for any help