Filters/FilterPng.cs

   1 //
   2 // FilterPng.cs
   3 //
   4 // Copyright (C) 2004 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a
   9 // copy of this software and associated documentation files (the "Software"),
  10 // to deal in the Software without restriction, including without limitation
  11 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12 // and/or sell copies of the Software, and to permit persons to whom the
  13 // Software is furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in
  16 // all copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24 // DEALINGS IN THE SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.IO;
  29
  30 using Beagle.Util;
  31 using Beagle.Daemon;
  32
  33 using SemWeb;
  34
  35 namespace Beagle.Filters {
  36
  37         public class FilterPng : FilterImage {
  38
  39                 public FilterPng () : base ()
  40                 {
  41                         AddSupportedFlavor (FilterFlavor.NewFromMimeType ("image/png"));
  42                 }
  43
  44                 protected override void PullImageProperties ()
  45                 {
  46                         PngHeader png = new PngHeader (Stream);
  47
  48                         foreach (PngHeader.Chunk chunk in png.Chunks){
  49                                 if (chunk is PngHeader.IhdrChunk) {
  50                                         PngHeader.IhdrChunk ihdr = (PngHeader.IhdrChunk)chunk;
  51
  52                                         Width = (int)ihdr.Width;
  53                                         Height = (int)ihdr.Height;
  54                                         Depth = ihdr.Depth;
  55
  56                                         bool hasAlpha = false;
  57                                         string colorType = null;
  58
  59                                         switch (ihdr.Color) {
  60                                         case PngHeader.ColorType.Gray:
  61                                                 colorType = "Greyscale";
  62                                                 hasAlpha = false;
  63                                                 break;
  64                                         case PngHeader.ColorType.Rgb:
  65                                                 colorType = "Truecolor";
  66                                                 hasAlpha = false;
  67                                                 break;
  68                                         case PngHeader.ColorType.Indexed:
  69                                                 colorType = "Indexed";
  70                                                 hasAlpha = false;
  71                                                 break;
  72                                         case PngHeader.ColorType.GrayAlpha:
  73                                                 colorType = "Greyscale";
  74                                                 hasAlpha = true;
  75                                                 break;
  76                                         case PngHeader.ColorType.RgbAlpha:
  77                                                 colorType = "Truecolor";
  78                                                 hasAlpha = true;
  79                                                 break;
  80                                         }
  81
  82                                         AddProperty (Beagle.Property.NewUnsearched ("fixme:colortype", colorType));
  83                                         AddProperty (Beagle.Property.NewBool ("fixme:hasalpha", hasAlpha));
  84                                 } else if (chunk is PngHeader.TextChunk) {
  85                                         ExtractTextProperty ((PngHeader.TextChunk) chunk);
  86                                 }
  87                         }
  88
  89                         Finished ();
  90                 }
  91
  92                 private void ExtractTextProperty (PngHeader.TextChunk tchunk)
  93                 {
  94                         switch (tchunk.Keyword) {
  95                         case "Title":
  96                                 AddProperty (Beagle.Property.New ("dc:title", tchunk.Text));
  97                                 break;
  98                         case "Author":
  99                                 AddProperty (Beagle.Property.New ("dc:creator", tchunk.Text));
 100                                 break;
 101                         case "Copyright":
 102                                 AddProperty (Beagle.Property.New ("dc:rights", tchunk.Text));
 103                                 break;
 104                         case "Description":
 105                                 AddProperty (Beagle.Property.New ("png:description", tchunk.Text));
 106                                 break;
 107                         case "Comment":
 108                                 AddProperty (Beagle.Property.New ("png:comment", tchunk.Text));
 109                                 break;
 110                         case "XMP":
 111                         case "XML:com.adobe.xmp":
 112                                 XmpFile xmp = new XmpFile (new MemoryStream (tchunk.TextData));
 113                                 AddXmpProperties (xmp);
 114                                 break;
 115                         case "Disclaimer":
 116                         case "Warning":
 117                         case "Source":
 118                         case "Creation Time":
 119                         case "Software":
 120                                 break;
 121                         }
 122                 }
 123         }
 124 }