C# 双线性和双立方卷积插值

/*        
输入:float[,] dem_in:二维数字高程数组
     float scaleX:宽度放大倍数
     float scaleY:高度放大倍数
     int interp_type:选择内插算法 0:双线性内插,1:双立方卷积内插
输出:float[,] dem_out:放大后的二维数字高程数组

例:
float[,] dem_out;

Zoom(dem_in, dem_out, 5, 10, 0);  //采用双线性内插算法将dem_in的宽度放大5倍,高度放大10倍后存入dem_out中
或Zoom(dem_in, dem_out, 5, 1); //采用双立方卷积内插算法将dem_in放大5倍后存入dem_out中

附:
采用立方卷积内插算法时针对不同模型可调整参数a的值以实现最佳效果,a的典型值为-1, -0.5, -0.75, 0.5, 0.75, 1,默认值为-0.75
*/
public void Zoom(ref float[,] dem_in, out float[,] dem_out, float scaleX, float scaleY, int interp_type)
        {
            try
            {
                if (interp_type == 0)
                {
                    Zoom_bilinear_interp(ref dem_in, out dem_out, scaleX, scaleY);
                }
                else if (interp_type == 1)
                {
                    Zoom_cubic_interp(ref dem_in, out dem_out, scaleX, scaleY);
                }
                else
                {

                    dem_out = new float[0, 0];
                    return;
                }
            }
            catch(Exception e)
            {
                MessageBox.Show(e.Message.ToString());
                dem_out = new float[0, 0];
                return;
            }
        }

        public void Zoom(ref float[,] dem_in, out float[,] dem_out, float scale, int interp_type)
        {
            Zoom(ref dem_in, out dem_out, scale, scale, interp_type);
        }

        private void Zoom_bilinear_interp(ref float[,] dem_in, out float[,] dem_out, float scaleX, float scaleY)
        {
            int originalHeight = dem_in.GetLength(0);
            int originalWidth = dem_in.GetLength(1);

            int newHeight = (int)(originalHeight * scaleY);
            int newWidth = (int)(originalWidth * scaleX);

            dem_out = new float[newHeight, newWidth];
            float u = 0f, v = 0f, x = 0f, y = 0f;
            int m = 0, n = 0;
            for (int i = 0; i < newHeight; ++i)
            {