private void WriteImageDesc()
{
_fs.WriteByte(0x2c); // image separator
WriteShort(0); // image position x,y = 0,0
WriteShort(0);
WriteShort(_width); // image size
WriteShort(_height);
// packed fields
if (_firstFrame)
// no LCT - GCT is used for first (or only) frame
_fs.WriteByte(0);
else
// specify normal LCT
_fs.WriteByte(Convert.ToByte(0x80 | // 1 local color table 1=yes
0 | // 2 interlace - 0=no
0 | // 3 sorted - 0=no
0 | // 4-5 reserved
_palSize)); // 6-8 size of color table
}