An observation on TIFF compression in CS6 and LR4
/forum/topic/1178354/0



bbbdco
Registered: Aug 09, 2004
Total Posts: 4
Country: United States

Can some one please explain this observation to me:

I took a flattened TIFF 16 image in CS6 and saved it with ZIP compression on my Mac computer.

I took the identical TIFF 16 image in LR4 and saved it with ZIP compression.

The results are as follows:

Size of original TIFF file: 83.1 MB

Size of TIFF saved with CS6 ZIP: 80.7 MB

Size of the same TIFF saved with LR4 ZIP: 69.7 MB

It's as if the LR4 version of ZIP compression works better than the CS6 version. Is this possible? I can't find any info on the internet to help me with this.

Dan



WAYCOOL
Registered: May 15, 2004
Total Posts: 2421
Country: United States

I have no idea what's going on but it is possible zip a file in more than one way and get different compression.



Greg Campbell
Registered: Jan 10, 2004
Total Posts: 1308
Country: United States

Must be one of those 'Mac things.'

Actually, there are many different ways to apply the basic Zip compression technique. (Technically, Zip is a different and somewhat more efficient compression scheme than the 'LZW' scheme used in a Tiff.) Whenever compressing, the computer has a window of data in which it tries to find duplicate data. Besides using different routines, different compression programs/implementations usually offer varying/user defined window (also called dictionary) sizes. I think most graphics formats, such as Tiff, Gif, etc., only looks at one row of pixels at a time, whereas a general purpose Zip program may have a window of many megabytes. The larger the window, and the more sophisticated the compression scheme, the greater the potential compression.



morganb4
Registered: Nov 03, 2005
Total Posts: 5313
Country: Australia

Why do you use TIFF compression? srs question...



bbbdco
Registered: Aug 09, 2004
Total Posts: 4
Country: United States

I do not use Tiff Compression. I was just researching it to see how much it would compress my files in case I wanted to change the way I save my photos. Obviously, LR4 does a better job at compression. I have about 10 Terabytes of photos, and was just considering a way to possibly save some room. But have not made any decisions. Everything is currently backed up to 3 separate systems (hard drives, RAID, Time Machine, etc.)

Dan



morganb4
Registered: Nov 03, 2005
Total Posts: 5313
Country: Australia

Was asking because having compressed TIFFS gives you a performance hit in PS, in terms of opening and closing files.



knower
Registered: Aug 13, 2012
Total Posts: 111
Country: Canada

It's not to exclude that Photoshop saves information in a different way than LR because of the header of the file.
This happens usually between different software and changes the ratio of the compression quite a bit.

Nothing to really worry about though

G.