public override ImageMetaData ReadMetaData(Stream stream)
{
if (0xff != stream.ReadByte() || 0xd8 != stream.ReadByte())
{
return(null);
}
using (var file = new ArcView.Reader(stream))
{
while (-1 != file.PeekChar())
{
ushort marker = Binary.BigEndian(file.ReadUInt16());
if ((marker & 0xff00) != 0xff00)
{
break;
}
int length = Binary.BigEndian(file.ReadUInt16());
if ((marker & 0x00f0) == 0xc0 && marker != 0xffc4)
{
if (length < 8)
{
break;
}
int bits = file.ReadByte();
uint height = Binary.BigEndian(file.ReadUInt16());
uint width = Binary.BigEndian(file.ReadUInt16());
int components = file.ReadByte();
return(new ImageMetaData {
Width = width,
Height = height,
BPP = bits * components,
});
}
file.BaseStream.Seek(length - 2, SeekOrigin.Current);
}
return(null);
}
}
public override ImageMetaData ReadMetaData(Stream stream)
{
if (0xff != stream.ReadByte() || 0xd8 != stream.ReadByte())
return null;
using (var file = new ArcView.Reader (stream))
{
while (-1 != file.PeekChar())
{
ushort marker = Binary.BigEndian (file.ReadUInt16());
if ((marker & 0xff00) != 0xff00)
break;
int length = Binary.BigEndian (file.ReadUInt16());
if ((marker & 0x00f0) == 0xc0 && marker != 0xffc4)
{
if (length < 8)
break;
int bits = file.ReadByte();
uint height = Binary.BigEndian (file.ReadUInt16());
uint width = Binary.BigEndian (file.ReadUInt16());
int components = file.ReadByte();
return new ImageMetaData {
Width = width,
Height = height,
BPP = bits * components,
};
}
file.BaseStream.Seek (length-2, SeekOrigin.Current);
}
return null;
}
}
public override ImageMetaData ReadMetaData(Stream stream)
{
using (var file = new ArcView.Reader(stream))
{
short id_length = file.ReadByte();
short colormap_type = file.ReadByte();
if (colormap_type > 1)
{
return(null);
}
short image_type = file.ReadByte();
ushort colormap_first = file.ReadUInt16();
ushort colormap_length = file.ReadUInt16();
short colormap_depth = file.ReadByte();
int pos_x = file.ReadInt16();
int pos_y = file.ReadInt16();
uint width = file.ReadUInt16();
uint height = file.ReadUInt16();
int bpp = file.ReadByte();
if (bpp != 32 && bpp != 24 && bpp != 16 && bpp != 15 && bpp != 8)
{
return(null);
}
short descriptor = file.ReadByte();
uint colormap_offset = (uint)(18 + id_length);
switch (image_type)
{
default: return(null);
case 1: // Uncompressed, color-mapped images.
case 9: // Runlength encoded color-mapped images.
case 32: // Compressed color-mapped data, using Huffman, Delta, and
// runlength encoding.
case 33: // Compressed color-mapped data, using Huffman, Delta, and
// runlength encoding. 4-pass quadtree-type process.
if (colormap_depth != 24 && colormap_depth != 32)
{
return(null);
}
break;
case 2: // Uncompressed, RGB images.
case 3: // Uncompressed, black and white images.
case 10: // Runlength encoded RGB images.
case 11: // Compressed, black and white images.
break;
}
return(new TgaMetaData {
OffsetX = pos_x,
OffsetY = pos_y,
Width = width,
Height = height,
BPP = bpp,
ImageType = image_type,
ColormapType = colormap_type,
ColormapOffset = colormap_offset,
ColormapFirst = colormap_first,
ColormapLength = colormap_length,
ColormapDepth = colormap_depth,
Descriptor = descriptor,
});
}
}
public override ImageMetaData ReadMetaData(Stream stream)
{
ImageMetaData meta = null;
var file = new ArcView.Reader(stream);
try
{
file.ReadUInt32();
if (file.ReadUInt32() != 0x0a1a0a0d)
{
return(null);
}
uint chunk_size = Binary.BigEndian(file.ReadUInt32());
char[] chunk_type = new char[4];
file.Read(chunk_type, 0, 4);
if (!chunk_type.SequenceEqual("IHDR"))
{
return(null);
}
meta = new ImageMetaData();
meta.Width = Binary.BigEndian(file.ReadUInt32());
meta.Height = Binary.BigEndian(file.ReadUInt32());
int bpp = file.ReadByte();
int color_type = file.ReadByte();
switch (color_type)
{
case 2: meta.BPP = bpp * 3; break;
case 3: meta.BPP = 24; break;
case 4: meta.BPP = bpp * 2; break;
case 6: meta.BPP = bpp * 4; break;
default: meta.BPP = bpp; break;
}
SkipBytes(file, 7);
for (;;)
{
chunk_size = Binary.BigEndian(file.ReadUInt32());
file.Read(chunk_type, 0, 4);
if (chunk_type.SequenceEqual("IDAT") || chunk_type.SequenceEqual("IEND"))
{
break;
}
if (chunk_type.SequenceEqual("oFFs"))
{
int x = Binary.BigEndian(file.ReadInt32());
int y = Binary.BigEndian(file.ReadInt32());
if (0 == file.ReadByte())
{
meta.OffsetX = x;
meta.OffsetY = y;
}
break;
}
SkipBytes(file, chunk_size + 4);
}
}
catch
{
meta = null;
}
finally
{
file.Dispose();
if (stream.CanSeek)
{
stream.Position = 0;
}
}
return(meta);
}