Hello,
I'm looking for directions on how to manipulate, programmatically,
very large GeoTIFF images.
My concern is about memory exhaustion and I'm looking for some
technique (or library) capable of doing image manipulations without
loading the entire image in memory.
I'm completely new to the subject of GIS and image processing, and
forgive me if I misplaced the post.
Best regards,
Eduardo
I'm looking for directions on how to manipulate, programmatically,
very large GeoTIFF images.My concern is about memory exhaustion and I'm looking for some
technique (or library) capable of doing image manipulations without
loading the entire image in memory.
Hi Eduardo,
How big is "very large"?
I loaded a 1.8gb GeoTIFF (no compression) into GRASS the other day with
r.in.gdal. No problems. (GRASS got the job because ERDAS choked on it)
GRASS does most raster processing with only one row of data in memory at
a time so it handles huge images & fine resolutions quite nicely.
(noteable exception I know of: r.in|out.mat)
Large file support (LFS, ie >2gb) is in newer versions of GRASS, but
is only lightly tested. "./configure --enable-largefile"
For more general GeoTIFF manipulations that don't really need a full
GIS, you might do better to use the gdal tools directly:
gdal_translate & gdalwarp from http://www.gdal.org.
Hamish
Hi Hamish,
Thanks for the reply.
I'm new to the field of image manipulation and GIS, so I'm a little
lost in what direction I should take. I only found about GRASS
searching the subject of image manipulation on the Internet.
What I really need is a library that implements the memory allocation
and image manipuation routines for GeoTIFF images. And, since the
images are big (from 1Gb to 2Gb) it must not load the entire image
in memory. This library will be the basis of a custon GeoTIFF viewer
application.
Do you think I can find something like this in http://www.gdal.org ?
My best regards,
Eduardo
On 6/22/05, Hamish <hamish_nospam@yahoo.com> wrote:
> I'm looking for directions on how to manipulate, programmatically,
> very large GeoTIFF images.
>
> My concern is about memory exhaustion and I'm looking for some
> technique (or library) capable of doing image manipulations without
> loading the entire image in memory.Hi Eduardo,
How big is "very large"?
I loaded a 1.8gb GeoTIFF (no compression) into GRASS the other day with
r.in.gdal. No problems. (GRASS got the job because ERDAS choked on it)GRASS does most raster processing with only one row of data in memory at
a time so it handles huge images & fine resolutions quite nicely.
(noteable exception I know of: r.in|out.mat)Large file support (LFS, ie >2gb) is in newer versions of GRASS, but
is only lightly tested. "./configure --enable-largefile"For more general GeoTIFF manipulations that don't really need a full
GIS, you might do better to use the gdal tools directly:
gdal_translate & gdalwarp from http://www.gdal.org.Hamish
Also, if you are using MacOS X.3 and earlier, you can't access > 2gb files.
By any chance has anyone tried Tiger and large files yet? In theory Tiger
should have started supporting 64-bit file access...
--j
On 6/21/05 10:40 PM, "Hamish" <hamish_nospam@yahoo.com> wrote:
I'm looking for directions on how to manipulate, programmatically,
very large GeoTIFF images.My concern is about memory exhaustion and I'm looking for some
technique (or library) capable of doing image manipulations without
loading the entire image in memory.Hi Eduardo,
How big is "very large"?
I loaded a 1.8gb GeoTIFF (no compression) into GRASS the other day with
r.in.gdal. No problems. (GRASS got the job because ERDAS choked on it)GRASS does most raster processing with only one row of data in memory at
a time so it handles huge images & fine resolutions quite nicely.
(noteable exception I know of: r.in|out.mat)Large file support (LFS, ie >2gb) is in newer versions of GRASS, but
is only lightly tested. "./configure --enable-largefile"For more general GeoTIFF manipulations that don't really need a full
GIS, you might do better to use the gdal tools directly:
gdal_translate & gdalwarp from http://www.gdal.org.Hamish
--
Jonathan A. Greenberg, PhD
NRC Research Associate
NASA Ames Research Center
MS 242-4
Moffett Field, CA 94035-1000
650-604-5896
AIM: jgrn307
MSN: jgrn307@hotmail.com
What I really need is a library that implements the memory allocation
and image manipuation routines for GeoTIFF images. And, since the
images are big (from 1Gb to 2Gb) it must not load the entire image
in memory. This library will be the basis of a custon GeoTIFF viewer
application.Do you think I can find something like this in http://www.gdal.org ?
GDAL is exactly what you are looking for.
Hamish