2008.08.22 16:40 "Re: [Tiff] creating sparse files......", by Bob Friesenhahn
libtiff is a library that is commonly used by programs that need tiff input/output. How many of those are going to explictly write large amounts (you need at least 4k before the OS will leave a block open!), of zeroes and then edit the tiff file inplace?
I can't say. It does not really matter how many such applications there are (just takes one) if the code is to be placed into libtiff itself. Libtiff is a high-performance library which is expected to go super fast as long as compression is not used.
Yes, enabeling compression should work wonders. Somehow I'm stuck with an application suite which suddenly lost the option to pass the compression flags around.
I see. If you did have control over the application, then you could supply your own I/O module which does exactly what you want without modifying libtiff at all.
Given that this is the case, having libtiff create sparse files for files that ARE sparse, seems like something that is useful in general. For example, in the application suite I'm talking about (hugin/panotools), someone might have decided that for the short-lived temp files, compression and decompression wastes CPU cycles.
If these are open source applications then you should be able to modify them and submit a patch to the authors.
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/