2009.01.13 13:23 "Re: [Tiff] Libtiff compression ratios", by Gerben Vos
I am not sure if these parameters are available for ZIP compression using 'tiffcp'. The 'tiffcp' manual page does not seem to address ZIP compression, although it does discuss LZW.
The tiffcp help output says you can use the predictor option with ZIP compression, like "-c zip:2". But you can't set the compression quality this way.