Ciao John, please read below...
On 11/20/06, John Mitchell <mitchelljj98@anonymised.com> wrote:
Chris,
Thanks for your response. I will attempt to summarize what you just wrote
in order to make sure that I understand you fully.
When GeoServer 1.5 comes out it will include the ability to handle and
display ECW format files. Will this include the ECW plug in?
We have been inspecting various ways for supporting ECW data sources
in GeoTools,GeoServer:
-1- Using the old Java bindings provided by ERMapper
-2- Using GDAL Java bindings
-3- Wrting SWIG binding directly for ECW.
I tried the first one but I quickly dropped it because it was pretty
bad. GeoTools raster support sits on top of ImageIO and JAI and those
bindings were not what we needed to respect this stack
The third one would be the best one but it is very very very complex
and for the moment we decided to not pursue it.
The solution we pursued was using the GDAL java bindings which allows
to connects to a wide variety of datasources comprehending ECW through
ERMapper lib.
As of now we have a decent versions of them working on JPEG2K, ECW,
HDF and a couple of other formats. We have not released yet because
there is still some work to do in order to improve quality and further
investigate some possible issues with thread-safety problems with GDAL
itself (anyway, if just talking about reading capabilities things
should be fine).
If I wanted to utilize ECW within GeoServer sooner I could utilize the
initial beta version which will be coming out quite soon, but I would have
to implement the ECW plug in or contract out this task to Simone and
Alessio.
Well, whether or not pursue the GeoServer road and who to ask for
implementing the ECW is your choice. What I can say is that we have
already worked out a decent ECW plugin even though as I said before it
still needs some testing and quality improvements.
Any idea on when the 1.5 beta is coming out? Any idea on when the
1.5 stable is coming out? So I should just keep checking the web site on
the download link in order to see if the latest beta version is 1.5 or the
latest stable version is 1.5 .
A beta version is foreseen quite soon. The GeoServer team (well, the
TOPP GeoServer team) is now busy with 1.4 and OWS4 but right after it
a beta version of GeoServer 1.5 should come out. At least these are
the plans. However, this is for anybody who may be interested,
fundings can change/shorten/grow plans for releases.
Any idea on the performance of GeoServer in
handling ECW files?
Well so far using the GDAL bindings, performances have been pretty
good. At foss06 I was going around with my laptop to show people a
working example of a 450mb geotiff compressed a ECW and it was pretty
good. However, there area couple of things that I would like to do in
order to increase performances.
Last week I wanted to see if there was an alternate to utilizing Pixia
software (which is very very expensive) in displaying raster data within a
web browser, so I sent an email to the mapbuilder developers mail list and
it was suggested that I consider uses either ER Mapper (which is very
expensive but not as expensive as Pixia) or mapserver which is an open
source product. I have already installed the trial version of both ER
Mapper Professional ($1000 for MBC and $7700 for professional) which
converts raster files into either ECW or Jpeg 2000 compressed files
If you want to compress data into ECW you will have to buy the codec
from ERMapper anyway. The free version work s with files under 500mb.
Using a mosaic plugin in conjunction with the free codec you can use a
lot of data at a time.
and ER
Mapper Image Web Server (IWS which costs $68,000 for unlimited terabytes)
which displays both ECW and Jpeg 2000 format files. Both Pixia and ER
Mapper IWS advertise there products as being able to display terabytes of
information very quickly.
I have never seen Pixia at work, but ERMapper IWS is really fast (no
surprise, they created the ECW format!).
Any idea on GeoServer 1.5 ability to handle terabytes of ECW format files
and far as stability and speed?
Well, as you can Imagine from what I said previously I cannot really
answer this question. I can tell you that I have tried data in ECW
format up to 500mb and I have tried Pyramids of geotiff of around
20gb. It is in general hard to talk about terabytes even because 1
terabyte can be both 20.000 files of 50mb as well as 10 files of 10 Gb
which already makes enough difference.
Everything being equal I would like to have GeoServer handle my raster data
since I already have it handle my PostGIS data. With Pixia I need a
separate Pixia apache server, with ER Mapper IWS I need to have IIS, and
MapServer has it's own server also.
I agree with that. I personally usually run mapserver+geoserver but it
is often a pain. The reason why I started the GeoServer-raster project
along with my colleague Alessio Fabiani was because I wanted to have
everything in GeoServer and I have to say that we are getting there,
it has been hard but we are getting there. I can't wait to see all the
GeoServer developers working on 1.5....
Regards,
Simone.
Thanks,
John Mitchell
--
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Eng. Simone Giannecchini
President /CEO GeoSolutions
http://www.geo-solutions.it
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