ImageProcessor.cs 3.9 KB

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  1. using System;
  2. using System.Drawing;
  3. using System.Drawing.Drawing2D;
  4. using System.Drawing.Imaging;
  5. using System.IO;
  6. using MediaBrowser.Common.Drawing;
  7. namespace MediaBrowser.Api
  8. {
  9. public static class ImageProcessor
  10. {
  11. /// <summary>
  12. /// Resizes an image from a source stream and saves the result to an output stream
  13. /// </summary>
  14. /// <param name="width">Use if a fixed width is required. Aspect ratio will be preserved.</param>
  15. /// <param name="height">Use if a fixed height is required. Aspect ratio will be preserved.</param>
  16. /// <param name="maxWidth">Use if a max width is required. Aspect ratio will be preserved.</param>
  17. /// <param name="maxHeight">Use if a max height is required. Aspect ratio will be preserved.</param>
  18. /// <param name="quality">Quality level, from 0-100. Currently only applies to JPG. The default value should suffice.</param>
  19. public static void ProcessImage(Stream sourceImageStream, Stream toStream, int? width, int? height, int? maxWidth, int? maxHeight, int? quality)
  20. {
  21. Image originalImage = Image.FromStream(sourceImageStream);
  22. Size newSize = DrawingUtils.Resize(originalImage.Size, width, height, maxWidth, maxHeight);
  23. Bitmap thumbnail = new Bitmap(newSize.Width, newSize.Height, originalImage.PixelFormat);
  24. thumbnail.SetResolution(originalImage.HorizontalResolution, originalImage.VerticalResolution);
  25. Graphics thumbnailGraph = Graphics.FromImage(thumbnail);
  26. thumbnailGraph.CompositingQuality = CompositingQuality.HighQuality;
  27. thumbnailGraph.SmoothingMode = SmoothingMode.HighQuality;
  28. thumbnailGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;
  29. thumbnailGraph.PixelOffsetMode = PixelOffsetMode.HighQuality;
  30. thumbnailGraph.CompositingMode = CompositingMode.SourceOver;
  31. thumbnailGraph.DrawImage(originalImage, 0, 0, newSize.Width, newSize.Height);
  32. Write(originalImage, thumbnail, toStream, quality);
  33. thumbnailGraph.Dispose();
  34. thumbnail.Dispose();
  35. originalImage.Dispose();
  36. }
  37. private static void Write(Image originalImage, Image newImage, Stream toStream, int? quality)
  38. {
  39. // Use special save methods for jpeg and png that will result in a much higher quality image
  40. // All other formats use the generic Image.Save
  41. if (ImageFormat.Jpeg.Equals(originalImage.RawFormat))
  42. {
  43. SaveJpeg(newImage, toStream, quality);
  44. }
  45. else if (ImageFormat.Png.Equals(originalImage.RawFormat))
  46. {
  47. newImage.Save(toStream, ImageFormat.Png);
  48. }
  49. else
  50. {
  51. newImage.Save(toStream, originalImage.RawFormat);
  52. }
  53. }
  54. private static void SaveJpeg(Image newImage, Stream target, int? quality)
  55. {
  56. if (!quality.HasValue)
  57. {
  58. quality = 90;
  59. }
  60. using (EncoderParameters encoderParameters = new EncoderParameters(1))
  61. {
  62. encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, quality.Value);
  63. newImage.Save(target, GetImageCodeInfo("image/jpeg"), encoderParameters);
  64. }
  65. }
  66. private static ImageCodecInfo GetImageCodeInfo(string mimeType)
  67. {
  68. ImageCodecInfo[] info = ImageCodecInfo.GetImageEncoders();
  69. for (int i = 0; i < info.Length; i++)
  70. {
  71. ImageCodecInfo ici = info[i];
  72. if (ici.MimeType.Equals(mimeType, StringComparison.OrdinalIgnoreCase))
  73. {
  74. return ici;
  75. }
  76. }
  77. return info[1];
  78. }
  79. }
  80. }