[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
opening and display large file
- Subject: opening and display large file
- From: Sylvain Carette <sylvainc(at)total.net>
- Date: Wed, 30 Aug 2000 06:56:10 GMT
- Newsgroups: comp.lang.idl-pvwave
- Organization: Sympatico
- Xref: news.doit.wisc.edu comp.lang.idl-pvwave:21166
How do you manage to display very large images? What is the options?
From the manual, it seem that using "assoc" is a winner but maybe
with one little example it would be more clear how can this be (It seem
to me that it is an important aspect of programming with IDL since most
of the time you'll deal with larger than memory files).
Even with assoc, dont you still have to copy from the file to an
array before display?
I dont decipher exactly why and when to use readu or read_binary,
the file pointer, assoc or writing to an offscreen buffer.
I tried to open and display a GTOPO30 tile (4800 x 6000 int). tv
could not display it - froze. I tried "slide_image" but it didnt scroll
with "retain=1" while "retain=2" and "retain=3" result in windows error
Since most of my data fall in the 30mb to 610 mb range, I need absolutely
to open and display very large file. What is available? Pointers, sample
code, library, ideas, etc, I'm listening.... Just knowing that it have
to be handled on your own or that IDL provide facility (that they forgot
to explain in the manual) to deal with this will already be invaluable