On 11/19/2011 10:55 PM, Puneet Kishor wrote:
Hi all,
Am following up on reading ERDAS Imagine files with PDL. I tried
reading it with PDL::IO::FlexRaw but failed. I have put a sample
Imagine file on my Dropbox http://dl.dropbox.com/u/3526821/r_1.img if
someone else wants to give it a whirl.
Of course, I can read it well with the various utility programs
provided by GDAL, however, PDL would give me better ability to do
computations on parts of the data. The gdal utilities provided are
fairly simplistic.
As mentioned earlier, the chief interest here is to read the ERDAS
file directly by PDL, if at all possible, because converting it to an
intermediate format would require more tools and more steps in the
processing chain.
This has set me thinking -- it would be wonderful to actually have a
PDL::GDAL module in the spirit of PDL::GIS::Proj and
PDL::Transform::Cartography (probably, a long term effort might want
to focus on bringing all the GIS-related modules under an umbrella
PDL::Geo:: namespace). GDAL (http://www.gdal.org/), and its
associated vector IO library OGR (http://www.gdal.org/ogr/index.html)
can read and write a lot of different formats, so PDL would
automagically get the same abilities.
Also of interest -- I recently stumbled upon an image IO library
called Bio-Formats (developed right here on my campus). It is
Java-based, so I don't know if it can be embraced by PDL, but it can
read many, many different scientific image formats, and write out a
few standard ones. More info on Bio-Formats is at
http://loci.wisc.edu/software/bio-formats
Maybe the Java or Java::Import module would be of
use to you here. I haven't used these modules but
the documentation look good for what you are wanting
to do...
On Nov 10, 2011, at 3:15 PM, Puneet Kishor wrote:
Thanks Chris,
On Nov 10, 2011, at 3:09 PM, Chris Marshall wrote:
Maybe this img2tif utility is relevant?
http://home.gdal.org/projects/imagine/hfa_index.html
I am already using gdal to directly read the .img files, so that is
not an issue. The reason I want to read those files in PDL is so I
can do query and analysis more than what gdal can do. For example,
gdal can query the value at a location (a specific x,y location),
but I'd like to query an area (a polygon), and create summary stats
for that area. I thinking PDL can give me more flexibility.
Otherwise, you can cook up a way to read the files from the file
format information (if it is available). Another possibility is
to use another program to convert the files to something that is
already directly readable in PDL.
I'd rather not. In other words, I already have ERDAS files, and can
read them directly with gdal without further manipulation. I'd
rather not inject an extra step in between. Besides the burden of
an extra step, I would probably lose information when converting it
from Imagine to something like tiff.
--Chris
On Thu, Nov 10, 2011 at 3:36 PM, Puneet
Kishor<[email protected]> wrote:
Is there a way I can read in .img files from ERDAS using PDL?
-- Puneet Kishor
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