title: Get EXIF Orientation Tag,Rotate to Proper Orientation, Process Image and Save the Image with proper Orientation
body: <p>My program processes some images in batch.I currently need to read the exif orientation tag of the image,rotate it to proper orientation,do some processing and save the image without any EXIF Orientation Tag,but with proper Rotation.(or with EXIF tag with Proper Orientation) </p>
  
  <p>I am reading EXIF and Rotating using <a href="http://www.codeproject.com/Articles/11305/EXIFextractor-library-to-extract-EXIF-information" rel="noreferrer">this library</a>:</p>
  
  <pre><code>  var bmp = new Bitmap(pathToImageFile);
      var exif = new EXIFextractor(ref bmp, "n"); // get source from http://www.codeproject.com/KB/graphics/exifextractor.aspx?fid=207371
  
      if (exif["Orientation"] != null)
      {
      RotateFlipType flip = OrientationToFlipType(exif["Orientation"].ToString());
  
      if (flip != RotateFlipType.RotateNoneFlipNone) // don't flip of orientation is correct
      {
      bmp.RotateFlip(flip);
      bmp.Save(pathToImageFile, ImageFormat.Jpeg);
      }
  
      // Match the orientation code to the correct rotation:
  
      private static RotateFlipType OrientationToFlipType(string orientation)
      {
      switch (int.Parse(orientation))
      {
      case 1:
      return RotateFlipType.RotateNoneFlipNone;
  
      case 2:
      return RotateFlipType.RotateNoneFlipX;
  
      case 3:
      return RotateFlipType.Rotate180FlipNone;
      case 4:
      return RotateFlipType.Rotate180FlipX;
      break;
      case 5:
      return RotateFlipType.Rotate90FlipX;
      break;
      case 6:
      return RotateFlipType.Rotate90FlipNone;
      case 7:
      return RotateFlipType.Rotate270FlipX;
      case 8:
      return RotateFlipType.Rotate270FlipNone;
      default:
      return 
  }
  }
  </code></pre>
  
  <p>This works. but when saving this image, the exif rotation tag still exists which makes the image to be in wrong orientation.
  What i can do is </p>
  
  <pre><code>       var bmp = new Bitmap(OS.FileName);       
         var exif = new EXIFextractor(ref bmp, "n");
         exif.setTag(0x112, "1");
         bmp.save("strippedexifimage");
  </code></pre>
  
  <p>But this code when used in a loop slows down my program by around 50%.Is there a alternative way? May be code to counter rotate the image after applying the rotation,will that work? </p>
  
  <p><strong><em>Update:</em></strong></p>
  
  <p>@Hans Passant Your answer works, but the result it produce is same as the ones produced by the library. When i use bitmap.save(),both library and your code works.But when i use the following code to save my image depending on the format selected by the user. Imgformat can be  <code>imgformat = "image/png";,imgformat = "image/jpeg";</code> etc some images still get saved with wrong exif orientation tag. ie: i see the wrong image preview in windows explorer,When i open the image with MS Paint,the image is having correct orientation.What im i doing wrong? Please help.</p>
  
  <pre><code>private void saveJpeg(string path, Bitmap img, long quality)
          {
  
  
              EncoderParameter qualityParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
  
  
              ImageCodecInfo Codec = this.getEncoderInfo(imgformat);
               if (Codec == null)
                return;
  
              EncoderParameters encoderParams = new EncoderParameters(1);
              encoderParams.Param[0] = qualityParam;    
              img.Save(path + ext, Codec, encoderParams);
          }
  
  
  
   private ImageCodecInfo getEncoderInfo(string mimeType)
          {
              // Get image codecs for all image formats
              ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
  
              // Find the correct image codec
              for (int i = 0; i &lt; codecs.Length; i++)
                  if (codecs[i].MimeType == mimeType)
                      return codecs[i];
              return null;
          }
  </code></pre>