2001.05.02 19:43 "Re: TIFFSetDirectory speed?", by Helge Blischke

How costly is it to set the directory in say a 5,000 page TIFF file? For instance, if I want to go to page 4,000 can libtiff easily jump there or does it actually have to read the previous 3,999 pages to get to page 4,000?

If I got the TIFF spec correctly, each page of a multipage TIFF file has it's own IFD, thus what you'd have to do is to walk through the IFD chain until the page number tag contains the desired page number.

As the spec allows the pages to be stored in any order, you may have to inspect more than your 3,000 IFDs.

Helge

H.Blischke@srz-berlin.de
H.Blischke@srz-berlin.com
H.Blischke@acm.org