AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2009.01.12 01:19 "[Tiff] Libtiff compression ratios", by myopicwatchmaker
2009.01.12 02:51 "Re: [Tiff] Libtiff compression ratios", by Bob Friesenhahn
2009.01.13 13:23 "Re: [Tiff] Libtiff compression ratios", by Gerben Vos
2009.01.12 16:50 "Re: [Tiff] Libtiff compression ratios", by Chris Cox
2009.01.13 21:01 "Re: [Tiff] Libtiff compression ratios", by Nick
2009.01.13 21:22 "Re: [Tiff] Libtiff compression ratios", by Bob Friesenhahn
2009.01.13 21:56 "Re: [Tiff] Libtiff compression ratios", by Toby Thain
2009.01.13 22:11 "Re: [Tiff] Libtiff compression ratios", by Frank Warmerdam

2009.01.13 21:56 "Re: [Tiff] Libtiff compression ratios", by Toby Thain

On 13-Jan-09, at 4:01 PM, Nick wrote:

Setting TIFFTAG_PREDICTOR to PREDICTOR_HORIZONTAL worked beautifully. With the predictor running, libtiff's compression ratios reach parity with Photoshop.

Increasing the deflate compression ratio to its maximum via TIFFTAG_ZIPQUALITY had only marginal effects on compression (a 2% improvement) while tripling the computation time required.

I appreciate the advice! Perhaps PREDICTOR_HORIZONTAL might make a good default value for the libtiff predictor tag?

It would restrict compatibility to those readers that implement the predictor.

--Toby

> Nick
>
>