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TIFF and LibTiff Mail List Archive

Thread

2014.12.21 20:12 "[Tiff] PNG in TIFF ?", by Ulf Zibis
2014.12.21 20:20 "Re: [Tiff] PNG in TIFF ?", by Toby Thain
2014.12.21 20:49 "Re: [Tiff] PNG in TIFF ?", by Joris Van Damme
2014.12.22 01:54 "Re: [Tiff] PNG in TIFF ?", by Tom Lane
2014.12.22 02:29 "Re: [Tiff] PNG in TIFF ?", by Bob Friesenhahn
2014.12.22 02:55 "Re: [Tiff] PNG in TIFF ?", by Toby Thain
2014.12.22 03:19 "Re: [Tiff] PNG in TIFF ?", by Bob Friesenhahn
2014.12.22 08:51 "Re: [Tiff] PNG in TIFF ?", by Joris Van Damme
2014.12.22 14:59 "Re: [Tiff] PNG in TIFF ?", by Tom Lane
2014.12.22 15:30 "Re: [Tiff] PNG in TIFF ?", by Joris Van Damme
2014.12.22 23:02 "Re: [Tiff] PNG in TIFF ?", by Ulf Zibis
2014.12.27 22:24 "Re: [Tiff] PNG in TIFF ?", by Ulf Zibis

2014.12.22 08:51 "Re: [Tiff] PNG in TIFF ?", by Joris Van Damme

Tom,

That's not really PNG's compression method though. PNG does use deflate but there is a pixel-differencing filter in front of that; for lots of image types the filtering step is critical to the amount of compression you can get.

I tend to always use flate compression with the Predictor tag, in TIFF. I found that does indeed make a lot of difference (no pun intended).

I take it what you're saying is that the differencing filters in PNG are more advanced, and that there's more of them to (automatically or semi-automatically) choose from? I always thought the law of diminishing returns would likely apply, but I've never actually attempted to really measure. Would it be safe to say that the simple Predictor scheme in TIFF goes a long way, you think, or do I overestimate its capability when it comes to the bottom line compressed file size?

Best regards,

Joris