OpencvSharp 使用透視變換。

static void Main(string[] args)
{
        // 輸入需要轉(zhuǎn)變的圖的四個角的坐標(biāo)（可以通過代碼獲得）
        var srcPoints = new Point2f[] {
            new Point2f(69, 110),
            new Point2f(81, 857),
            new Point2f(1042, 786),
            new Point2f(1038, 147),
        };

        // 需要轉(zhuǎn)換的圖指定轉(zhuǎn)換后四個角的坐標(biāo)
        var dstPoints = new Point2f[] {
            new Point2f(0, 0),
            new Point2f(0, 480),
            new Point2f(640, 480),
            new Point2f(640, 0),
        };

        using (var matrix = Cv2.GetPerspectiveTransform(srcPoints, dstPoints))
        using (var src = new Mat("Images/1.jpg"))
        using (var dst = new Mat(new Size(640, 480), MatType.CV_8UC3))
        {
            // 透視變換
            Cv2.WarpPerspective(src, dst, matrix, dst.Size());
            using (new Window("result", dst))
            {
                Cv2.WaitKey();
            }
        }
    }