Filters/FilterBmp.cs

   1 //
   2 // FilterBmp.cs
   3 //
   4 // Copyright (C) 2006 Alexander Macdonald <alex@alexmac.cc>
   5 //
   6
   7 // Permission is hereby granted, free of charge, to any person obtaining a
   8 // copy of this software and associated documentation files (the "Software"),
   9 // to deal in the Software without restriction, including without limitation
  10 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11 // and/or sell copies of the Software, and to permit persons to whom the
  12 // Software is furnished to do so, subject to the following conditions:
  13 //
  14 // The above copyright notice and this permission notice shall be included in
  15 // all copies or substantial portions of the Software.
  16 //
  17 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23 // DEALINGS IN THE SOFTWARE.
  24 //
  25
  26 using System;
  27 using System.IO;
  28 using System.Text;
  29
  30 using Beagle.Util;
  31 using Beagle.Daemon;
  32
  33 namespace Beagle.Filters
  34 {
  35         public class FilterBMP : FilterImage
  36         {
  37                 enum BitmapCompressionTypes {
  38                         None,
  39                         RunLength8Bit,
  40                         RunLength4Bit,
  41                         RGBBitmapWithMask
  42                 };
  43
  44                 struct BitmapHeader {
  45                         public ushort type;                          // Magic identifier
  46                         public uint size;                            // File size in bytes
  47                         //public ushort reserved1, reserved2;        // unused
  48                         public uint offset;                          // Offset to image data, bytes
  49                 };
  50
  51                 struct BitmapInfoHeader {
  52                         public uint size;                            // Header size in bytes
  53                         public int width,height;                     // width and height of image
  54                         public ushort planes;                        // Number of colour planes
  55                         public ushort bits;                          // Bits per pixel
  56                         public BitmapCompressionTypes compression;   // Compression type
  57                         public uint imagesize;                       // Image size in bytes
  58                         public int xresolution,yresolution;          // Pixels per meter
  59                         public uint ncolors;                         // Number of colours
  60                         public uint importantcolors;                 // Important colours
  61                 };
  62
  63                 public FilterBMP () : base ()
  64                 {
  65                         AddSupportedFlavor (FilterFlavor.NewFromMimeType ("image/bmp"));
  66                         PreLoad = false;
  67                 }
  68
  69                 protected override void PullImageProperties ()
  70                 {
  71                         byte [] data = new byte [54];
  72                         Stream.Read (data, 0, data.Length);
  73
  74                         // Read the Header
  75                         // We're not using it for anything, so we might as well not parse it.
  76                         /*
  77                         BitmapHeader bmh;
  78                         bmh.type        = EndianConverter.ToUInt16 (data, 0, true);
  79                         bmh.size        = EndianConverter.ToUInt32 (data, 2, true);
  80                         bmh.reserved1   = EndianConverter.ToUInt16 (data, 6, true);
  81                         bmh.reserved2   = EndianConverter.ToUInt16 (data, 8, true);
  82                         bmh.offset      = EndianConverter.ToUInt32 (data, 10, true);
  83                         */
  84
  85                         /* Read the Info Header */
  86                         BitmapInfoHeader bmih;
  87                         bmih.size               = EndianConverter.ToUInt32 (data, 14, true);
  88                         bmih.width              = EndianConverter.ToInt32  (data, 18, true);
  89                         bmih.height             = EndianConverter.ToInt32  (data, 22, true);
  90                         bmih.planes             = EndianConverter.ToUInt16 (data, 26, true);
  91                         bmih.bits               = EndianConverter.ToUInt16 (data, 28, true);
  92                         bmih.compression        = (BitmapCompressionTypes) EndianConverter.ToUInt32 (data, 30, true);
  93                         bmih.imagesize          = EndianConverter.ToUInt32 (data, 34, true);
  94                         bmih.xresolution        = EndianConverter.ToInt32  (data, 38, true);
  95                         bmih.yresolution        = EndianConverter.ToInt32  (data, 42, true);
  96                         bmih.ncolors            = EndianConverter.ToUInt32 (data, 46, true);
  97                         bmih.importantcolors    = EndianConverter.ToUInt32 (data, 50, true);
  98
  99                         Width = bmih.width;
 100                         Height = bmih.height;
 101                         Depth = bmih.bits;
 102
 103                         AddProperty (Beagle.Property.NewUnsearched ("exif:Planes", bmih.planes));
 104
 105                         switch  (bmih.compression) {
 106                                 case BitmapCompressionTypes.None:
 107                                         AddProperty (Beagle.Property.NewUnsearched ("exif:Compression", "none"));
 108                                         break;
 109                                 case BitmapCompressionTypes.RunLength8Bit:
 110                                         AddProperty (Beagle.Property.NewUnsearched ("exif:Compression", "8bit Runlength"));
 111                                         break;
 112                                 case BitmapCompressionTypes.RunLength4Bit:
 113                                         AddProperty (Beagle.Property.NewUnsearched ("exif:Compression", "4bit Runlength"));
 114                                         break;
 115                                 case BitmapCompressionTypes.RGBBitmapWithMask:
 116                                         AddProperty (Beagle.Property.NewUnsearched ("exif:Compression", "RGB bitmap with mask"));
 117                                         break;
 118                                 default:
 119                                         AddProperty (Beagle.Property.NewUnsearched ("exif:Compression", "unknown"));
 120                                         break;
 121                         }
 122
 123                         AddProperty (Beagle.Property.NewUnsearched ("exif:XResolution",     bmih.xresolution));
 124                         AddProperty (Beagle.Property.NewUnsearched ("exif:YResolution",     bmih.yresolution));
 125                         AddProperty (Beagle.Property.NewUnsearched ("exif:NumberOfColors",  bmih.ncolors));
 126                         AddProperty (Beagle.Property.NewUnsearched ("exif:ImportantColors", bmih.importantcolors));
 127                 }
 128         }
 129 }