| Re: Zipped Files [message #51853] |
Fri, 15 December 2006 06:16 |
David Fanning
Messages: 11724
Registered: August 2001
|
Senior Member |
|
|
Norbert Hahn writes:
> The problem may be worse than you might think. A zipped Tiff
> file has an uncompressed header, while the data part is zipped.
> Feeding the whole file into some unzip will not work. However,
> GeoTiff may be different than ordinary tiff files with zipped
> data.
I had no problems (that I noticed) upzipping and reading
the file. Do you mean some particular upzip applications
have problems with this, or... Not clear what you are
warning me about here. :-)
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")
|
|
|
|
| Re: Zipped Files [message #51854 is a reply to message #51853] |
Fri, 15 December 2006 05:41  |
Norbert Hahn
Messages: 46
Registered: May 2003
|
Member |
|
|
David Fanning <news@dfanning.com> wrote:
> Folks,
>
> Is there any possibility of reading zipped GeoTiff or
> HDF files directly in IDL? I'm a little pressed at the moment, but
> a quick reading of the documentation leads me to think not.
> Can anyone confirm that these files have to be unzipped first
> to read them?
The problem may be worse than you might think. A zipped Tiff
file has an uncompressed header, while the data part is zipped.
Feeding the whole file into some unzip will not work. However,
GeoTiff may be different than ordinary tiff files with zipped
data.
Norbert
|
|
|
|
| Re: Zipped Files [message #51859 is a reply to message #51854] |
Thu, 14 December 2006 17:49 |
Robbie
Messages: 165
Registered: February 2006
|
Senior Member |
|
|
David,
Generally not. Just about every data converter in IDL requests a
filename. None of them take a filehandle or string as the data source.
If they did then the solution would be much simpler.
Recent versions of windows support "compressed (zipped) directories",
but you can only see them in explorer. I think that there may be
software out there which mucks about with the filesystem driver to
trick other applications into thinking that compressed directories are
really there.
This is one of *those* features which makes IDL 10x harder than any
other language. It almost had me re-implementing IDLffXML* just so I
could feed a string into the XML parser.
Arrrrgh..... Now you share my frustration.
Robbie
http://www.barnett.id.au/idl
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
