/* File Header Section
* Len Description Value
* 4 Signature "8BPS"
* 2 Version 1
* 6 Reserved not used.
* 2 Channels 1 ~ 56
* 4 Height 1 ~ 30,000
* 4 Width 1 ~ 30,000
* 2 Color Depth 1, 8, 16, 32
* 2 Color Mode 1 ~ 9
*/
private static void ReadHeader(ref PsdInfo info, PSDReader reader)
{
// Signature
if (reader.ReadByte() != 0x38 ||
reader.ReadByte() != 0x42 ||
reader.ReadByte() != 0x50 ||
reader.ReadByte() != 0x53)
{
throw new NotSupportedException();
}
// Version
var version = reader.ReadInt16();
if (version != 1)
{
throw new NotSupportedException();
}
// Reserved
reader.Position += 6;
// Channels
info.Channels = reader.ReadInt16();
// Height
info.Height = reader.ReadInt32();
// Width
info.Width = reader.ReadInt32();
// Color Depth
info.ColorDepth = reader.ReadInt16();
info.ColorDepthBytes = info.ColorDepth / 8;
if (info.ColorDepthBytes != 1 &&
info.ColorDepthBytes != 2 &&
info.ColorDepthBytes != 4)
{
throw new NotSupportedException();
}
// Color Mode
info.ColorMode = (ColorMods)reader.ReadInt16();
if (info.ColorMode == ColorMods.Bitmap)
{
throw new NotSupportedException();
}
info.Pixcels = info.Width * info.Height;
info.SizePerChannel = info.Pixcels * info.ColorDepthBytes;
}
// By RyuaNerin
private static void RLEDecompress(PSDReader reader, byte[] output, int count)
{
// https://en.wikipedia.org/wiki/PackBits
int ind = 0;
int len;
byte val;
while (ind < count)
{
len = reader.ReadByte();
// (1 + n) literal bytes of data
// bin sb ub
// 0000 0000 0 128
// 0111 1111 127 127
if (len < 128) // 0 ~ 127
{
while (len-- >= 0)
{
output[ind++] = reader.ReadByte();
}
}
// One byte of data, repeated (1 – n) times in the decompressed output
// bin sb ub not +2 1-n
// 1111 1111 -1 256 0000 0000 0000 0010 2
// 1000 0001 -127 129 0111 1110 1000 0000 128
else if (128 < len)
{
val = reader.ReadByte();
len = (len ^ 0xFF) + 2;
while (len-- > 0)
{
output[ind++] = val;
}
}
}
}
// By RyuaNerin
private static void RLEDecompress(PSDReader reader, byte[] output, int count)
{
// https://en.wikipedia.org/wiki/PackBits
int ind = 0;
int len;
byte val;
while (ind < count)
{
len = reader.ReadByte();
// (1 + n) literal bytes of data
// bin sb ub
// 0000 0000 0 128
// 0111 1111 127 127
if (len < 128) // 0 ~ 127
{
while (len-- >= 0)
output[ind++] = reader.ReadByte();
}
// One byte of data, repeated (1 – n) times in the decompressed output
// bin sb ub not +2 1-n
// 1111 1111 -1 256 0000 0000 0000 0010 2
// 1000 0001 -127 129 0111 1110 1000 0000 128
else if (128 < len)
{
val = reader.ReadByte();
len = (len ^ 0xFF) + 2;
while (len-- > 0)
output[ind++] = val;
}
}
}
/* Image Resources Section
* Len Description Value
* 4 Length
* n Resource Block Data
*/
/* Image Resource Blocks
* Len Description Value
* 4 Signature '8BIM'
* 2 Resource Id
* n Name
* 4 Resource Data Length
* n Resource Data
*/
private static void ReadImageResources(ref PsdInfo info, PSDReader reader)
{
var length = reader.ReadInt32();
short id;
int len;
info.TransparencyIndex = -1;
long pos = reader.Position + length;
while (reader.Position < pos)
{
// Signature
if (reader.ReadByte() != 0x38 ||
reader.ReadByte() != 0x42 ||
reader.ReadByte() != 0x49 ||
reader.ReadByte() != 0x4D)
throw new NotSupportedException();
// Resource Id
id = reader.ReadInt16();
// Name
len = reader.ReadByte();
if (len > 0)
{
if((len % 2) != 0)
len = reader.ReadByte();
reader.Position += len;
}
reader.Position += 1;
// Data Length
len = reader.ReadInt32();
if (len % 2 != 0)
len++;
switch (id)
{
case 1005: // ResolutionInfo structure
info.DpiX = reader.ReadInt16();
reader.Position += 6;
info.DpiY = reader.ReadInt16();
reader.Position += 6;
break;
case 1047: // Transparency Index. 2 bytes for the index of transparent color, if any.
info.TransparencyIndex = reader.ReadInt16();
break;
default:
reader.Position += len;
break;
}
}
}
/* File Header Section
* Len Description Value
* 4 Signature "8BPS"
* 2 Version 1
* 6 Reserved not used.
* 2 Channels 1 ~ 56
* 4 Height 1 ~ 30,000
* 4 Width 1 ~ 30,000
* 2 Color Depth 1, 8, 16, 32
* 2 Color Mode 1 ~ 9
*/
private static void ReadHeader(ref PsdInfo info, PSDReader reader)
{
// Signature
if (reader.ReadByte() != 0x38 ||
reader.ReadByte() != 0x42 ||
reader.ReadByte() != 0x50 ||
reader.ReadByte() != 0x53)
throw new NotSupportedException();
// Version
var version = reader.ReadInt16();
if (version != 1)
throw new NotSupportedException();
// Reserved
reader.Position += 6;
// Channels
info.Channels = reader.ReadInt16();
// Height
info.Height = reader.ReadInt32();
// Width
info.Width = reader.ReadInt32();
// Color Depth
info.ColorDepth = reader.ReadInt16();
info.ColorDepthBytes = info.ColorDepth / 8;
if (info.ColorDepthBytes != 1 &&
info.ColorDepthBytes != 2 &&
info.ColorDepthBytes != 4)
throw new NotSupportedException();
// Color Mode
info.ColorMode = (ColorMods)reader.ReadInt16();
if (info.ColorMode == ColorMods.Bitmap)
throw new NotSupportedException();
info.Pixcels = info.Width * info.Height;
info.SizePerChannel = info.Pixcels * info.ColorDepthBytes;
}
/* Image Resources Section
* Len Description Value
* 4 Length
* n Resource Block Data
*/
/* Image Resource Blocks
* Len Description Value
* 4 Signature '8BIM'
* 2 Resource Id
* n Name
* 4 Resource Data Length
* n Resource Data
*/
private static void ReadImageResources(ref PsdInfo info, PSDReader reader)
{
var length = reader.ReadInt32();
short id;
int len;
info.TransparencyIndex = -1;
long pos = reader.Position + length;
while (reader.Position < pos)
{
// Signature
if (reader.ReadByte() != 0x38 ||
reader.ReadByte() != 0x42 ||
reader.ReadByte() != 0x49 ||
reader.ReadByte() != 0x4D)
{
throw new NotSupportedException();
}
// Resource Id
id = reader.ReadInt16();
// Name
len = reader.ReadByte();
if (len > 0)
{
if ((len % 2) != 0)
{
len = reader.ReadByte();
}
reader.Position += len;
}
reader.Position += 1;
// Data Length
len = reader.ReadInt32();
if (len % 2 != 0)
{
len++;
}
switch (id)
{
case 1005: // ResolutionInfo structure
info.DpiX = reader.ReadInt16();
reader.Position += 6;
info.DpiY = reader.ReadInt16();
reader.Position += 6;
break;
case 1047: // Transparency Index. 2 bytes for the index of transparent color, if any.
info.TransparencyIndex = reader.ReadInt16();
break;
default:
reader.Position += len;
break;
}
}
}