public DHT(DHT prev)
{
id = new byte[prev.id.Length];
head_length = prev.head_length;
prev.id.CopyTo(id, 0);
table = prev.table;
}
public Cjpeg(Cjpeg prev)
{
app0 = new APP0(prev.app0);
dqt = new DQT(prev.dqt);
dht = new DHT(prev.dht);
sof = new SOF0(prev.sof);
sos = new SOS(prev.sos);
cb = new CBlock(prev.cb);
}