Bitmap.LockBits

        private int[][] makeJaggedArray(int rowsCount, int columsCount)
        {
            int[][] jaggedArray = new int[rowsCount][];
            for (int row = 0; row < rowsCount; row++)
            {
                jaggedArray[row]= new int[columsCount];
            }
            return jaggedArray;
        }

        private int[][] makePixelsMatrix()
        {
            var bmp = new Bitmap(this.pictureBox1.Image);
            var rect = Rectangle.FromLTRB(0, 0, bmp.Width, bmp.Height);
            var data = bmp.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
            var matrix = makeJaggedArray(bmp.Height,bmp.Width);

            for (int row = 0; row < data.Height; row++)
            {
                var buffer = new int[data.Width];
                Marshal.Copy((data.Scan0 + row * data.Stride), buffer, 0, buffer.Length);
                for (int col = 0; col < data.Width; col++)
                {
                    matrix[row][col] = buffer[col];
                }
            }
            bmp.UnlockBits(data);
            return matrix;
        }

        private Bitmap MakeBitmapWithMatrix(int[][] matrix)
        {
            var myBitmap = new Bitmap(pictureBox1.Image.Width, pictureBox1.Image.Height);
            var rect = new Rectangle(0, 0, myBitmap.Width, myBitmap.Height);
            var data = myBitmap.LockBits(rect, ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);

            for (int row = 0; row < data.Height; row++)
            {
                Marshal.Copy(matrix[row], 0, (data.Scan0 + row * data.Stride), matrix[row].Length);
            }
            myBitmap.UnlockBits(data);
            return myBitmap;
        }