bool JPEGReader::Extract( ICCProfile& icc )
{
icc.Clear();
if ( !IsOpen() )
return false;
if ( jpeg_decompressor->marker_list == nullptr )
return true;
ByteArray iccData;
uint32 iccSize = 0;
uint32 iccChunkOffset = 0;
const ::jpeg_marker_struct* m = jpeg_decompressor->marker_list;
do
{
if ( !STRNCASECMP( (const char*)m->data, "ICC_PROFILE", 11 ) )
{
//
// ICC_PROFILE 0 i N ddddddddddddd...ddd
// -----------
// iCC id
//
// 0 = nul character
// i = index number of this chunk
// N = total number of chunks
// d = data bytes in this chunk
//
void* iccChunkData = m->data + 14;
// Allocate ICC data block when we see the first chunk.
if ( iccChunkOffset == 0 )
{
// iccChunkData points now to an ICC profile header.
// The first field in an ICC profile header is the uint32
// profile length in bytes. ICC profiles are encoded using
// big endian byte order.
iccSize = BigToLittleEndian( *(const uint32*)iccChunkData );
if ( iccSize == 0 )
return true;
iccData = ByteArray( size_type( iccSize ) );
}
uint32 iccChunkSize = m->data_length - 14;
// Guard us against insane ICC profile data.
if ( iccChunkOffset+iccChunkSize > iccSize )
return true;
::memcpy( iccData.At( iccChunkOffset ), iccChunkData, iccChunkSize );
iccChunkOffset += iccChunkSize;
// More chunks ?
if ( m->data[12] >= m->data[13] )
break;
}
}
while ( (m = m->next) != nullptr );
icc.Set( iccData );
return true;
}
