C#图像处理（4）：图像的剪裁

图像的剪裁方法，从中间剪裁返回剪裁后的左右两页，方法实现如下：

        /// <summary>
        /// 图片裁剪，返回左右两页
        /// </summary>
        /// <param name="Img">图片</param>
        /// <param name="RightMargin">从中间剪裁时左边图片向右偏移量</param>
        /// <param name="LeftMargin">从中间剪裁时右边图片向左偏移量</param>
        /// <returns>Dictionary</returns>
        public Dictionary<string, Bitmap> ImgDiv(Image Img, int RightMargin, int LeftMargin)
        {
            Dictionary<string, Bitmap> DictImg = new Dictionary<string, Bitmap>();
            //获取图片宽高
            int Width = Img.Width;
            int Height = Img.Height;
            //获取图片水平和垂直的分辨率
            float dpiX = Img.HorizontalResolution;
            float dpiY = Img.VerticalResolution;
            //创建一个位图文件
            Bitmap BitmapResult = new Bitmap((Width / 2) + RightMargin, Height, PixelFormat.Format24bppRgb);
            //设置位图文件的水平和垂直分辨率  与Img一致
            BitmapResult.SetResolution(dpiX, dpiY);
            //在位图文件上填充一个矩形框
            Graphics Grp = Graphics.FromImage(BitmapResult);
            System.Drawing.Rectangle Rec = new System.Drawing.Rectangle(0, 0, (Width / 2) + RightMargin, Height);
            Grp.DrawImage(Img, 0, 0, Rec, GraphicsUnit.Pixel);
            //返回位图文件
            Grp.Dispose();
            //获取左边图像
            DictImg["Left"] = BitmapResult;
            //在位图文件上填充一个矩形框
            Bitmap BitmapRight = new Bitmap((Width / 2) + LeftMargin, Height, PixelFormat.Format24bppRgb);
            BitmapRight.SetResolution(dpiX, dpiY);
            Graphics GrpRight = Graphics.FromImage(BitmapRight);
            System.Drawing.Rectangle RecRight = new System.Drawing.Rectangle((Width / 2) - LeftMargin, 0, (Width / 2) + LeftMargin, Height);
            GrpRight.DrawImage(Img, 0, 0, RecRight, GraphicsUnit.Pixel);
            //获取右边图像
            DictImg["Right"] = BitmapRight;
            GrpRight.Dispose();
            GC.Collect();
            //返回位图文件
            return DictImg;
        }