Work with matrix in emgu cv

Question

I have a matrix (2D) of an image in EMGU cv,how can I fill the rest of the matrix with zeros but keep a certain area(rectangle) with the original data?

Answer 1

    // Rectangle's parameters
    static int x = 3;
    static int y = 3;
    static int width = 2;
    static int height = 2;

    Rectangle specificArea = new Rectangle(x, y, width, height);

    // Your image matrix; 20x20 just a sample
    Matrix imageMatrix = new Matrix(20, 20);


    public Matrix cropMatrix()
    {
        // Crop a specific area from image matrix
        Matrix specificMatrix = imageMatrix.GetSubRect(specificArea);

        // Matrix with full of zeros and same size with imageMatrix
        Matrix croppedMatrix = imageMatrix.CopyBlank();

        for (int i = x; i < x+width; i++)
        {
            for (int j = y; j < y+height; j++)
            {
                // Set croppedMatrix with saved values
                croppedMatrix[i, j] = specificMatrix[i-x, j-y];
            }
        }

        return croppedMatrix;
    }