图片失真问题。

Question

我现在在做一个项目，就是将一些倾斜的TIF图片调正，然后切需要的部分出来，把新切出来的图片保存为 600 dpi,8 bpp,Lzw压缩的新TIF。在这个过程中发现了一个问题就是，切出来的图片会失真。后来发现，原来图片经过旋转之后，会造成失真的现象。请问大家有没有解决的方法，麻烦指点一二，我感激不尽。谢谢。下面是我用来旋转的算法。

  public Bitmap RotateImage(Image image, float angle)
    {
      if (image == null)
        throw new ArgumentNullException("image");
      if (angle == 0)
        return image as Bitmap;

      const double pi2 = Math.PI / 2.0;

      double oldWidth = (double)image.Width;//记录下图片原来的宽和高
      double oldHeight = (double)image.Height;

      double theta = ((double)angle) * Math.PI / 180.0;//弧度=角度*PI/180;

      double locked_theta = theta;

      while (locked_theta < 0.0)
        locked_theta += 2 * Math.PI;//locked=locked+2*Math.PI

      double newWidth, newHeight;
      int nWidth, nHeight;

      double adjacentTop, oppositeTop;
      double adjacentBottom, oppositeBottom;

      if ((locked_theta >= 0.0 && locked_theta < pi2) || (locked_theta >= Math.PI && locked_theta < (Math.PI + pi2)))
      {
        adjacentTop = Math.Abs(Math.Cos(locked_theta)) * oldWidth;
        oppositeTop = Math.Abs(Math.Sin(locked_theta)) * oldWidth;

        adjacentBottom = Math.Abs(Math.Cos(locked_theta)) * oldHeight;
        oppositeBottom = Math.Abs(Math.Sin(locked_theta)) * oldHeight;
      }
      else
      {
        adjacentTop = Math.Abs(Math.Sin(locked_theta)) * oldHeight;
        oppositeTop = Math.Abs(Math.Cos(locked_theta)) * oldHeight;

        adjacentBottom = Math.Abs(Math.Sin(locked_theta)) * oldWidth;
        oppositeBottom = Math.Abs(Math.Cos(locked_theta)) * oldWidth;
      }

      newWidth = adjacentTop + oppositeBottom;
      newHeight = adjacentBottom + oppositeTop;

      nWidth = (int)Math.Ceiling(newWidth);
      nHeight = (int)Math.Ceiling(newHeight);

      Bitmap rotatedBmp = new Bitmap(nWidth, nHeight);//,image.PixelFormat);
      rotatedBmp.SetResolution(image.HorizontalResolution, image.VerticalResolution);

      using (Graphics g = Graphics.FromImage(rotatedBmp))
      {
        Point[] points;
        if (locked_theta >= 0.0 && locked_theta < pi2)
        {
          points = new Point[] { 
											 new Point( (int) oppositeBottom, 0 ), 
											 new Point( nWidth, (int) oppositeTop ),
											 new Point( 0, (int) adjacentBottom )
										 };

        }
        else if (locked_theta >= pi2 && locked_theta < Math.PI)
        {
          points = new Point[] { 
											 new Point( nWidth, (int) oppositeTop ),
											 new Point( (int) adjacentTop, nHeight ),
											 new Point( (int) oppositeBottom, 0 )						 
										 };
        }
        else if (locked_theta >= Math.PI && locked_theta < (Math.PI + pi2))
        {
          points = new Point[] { 
											 new Point( (int) adjacentTop, nHeight ), 
											 new Point( 0, (int) adjacentBottom ),
											 new Point( nWidth, (int) oppositeTop )
										 };
        }
        else
        {
          points = new Point[] { 
											 new Point( 0, (int) adjacentBottom ), 
											 new Point( (int) oppositeBottom, 0 ),
											 new Point( (int) adjacentTop, nHeight )		
										 };
        }

        g.CompositingQuality = CompositingQuality.HighQuality;
        g.SmoothingMode = SmoothingMode.HighQuality;
        g.InterpolationMode = InterpolationMode.HighQualityBicubic;
        g.DrawImage(image, points);
      }
      return rotatedBmp;
    }

 

Answer 1

旋转图片用这个        public void KiRotate90()
        {
            this._img.RotateFlip(RotateFlipType.Rotate90FlipNone);
        }
 

Answer 2

如果可以的话：录制成Photoshop宏。调用宏就能完成上述全部工作，而且是整个目录批处理的。我对自己上万张数码照片就是这么干的。

Answer 3

请问photoshop的宏怎样用C#去调用。

Answer 4

谢谢你的回答。我需要旋转任意角度的。

Answer 5

我是在Photoshop里直接干的，没有用C#操作过Photoshop。

http://topic.csdn.net/t/20050331/12/3897236.html
http://www.adobe.com/devnet/photoshop/

Answer 6

谢谢前辈。请问前辈对C# 图像处理编程这一块熟不熟悉，如果熟悉，麻烦推荐些好的资料给我学习下。我刚接触这方面的内容，好多知识都不理解。不知道是不是C#对图像处理这一块不怎么强大，我总感觉有点缺陷。唉。。。