[OSGeo Africa] uDig and MRSID and how to move open source where you want

Jody Garnett jgarnett at refractions.net
Thu Nov 22 14:27:28 EST 2007

Good thing uDig developers lurk on this list (due to my time spent in 
Jo'burg last year).
> Hi all
> I’m taking the liberty of forwarding a query from a new list member re 
> UDig, MrSID and mobile devices to the list hoping that some of you 
> will be able to help him.
> Gavin
> Deon’s first questions:
>    1. I need to read/convert MrSid aerial photos to display them in
>       UDig but have not been able to find anything on the website. Any
>       ideas?
We have just added some experimental support for MRSID (via a GDAL 
bridge on the tech side of things) on uDig trunk. This is some paid work 
we are doing for a client; but the results are public in the source code 
tree. If you are interested jump on udig-devel and meet the developers.
>    1. Someone has asked me regarding installing UDig on a network and
>       I said that it was the best to run individual software on every
>       machine and just point it to the database. I have not had a
>       comeback but was just wondering…?
That sounds fine; udig would keep some configuration information per 
user in their app data directory on uDig. So far the only glitches have 
been due to Vista; more testing in the real world would be welcome.
>    1. We are thinking about linking some mobile devices to UDig but
>       can’t seem to find anything in this regard on the web. Any
>       suggestions in this regard?
What did you have in mind? So far community modules keep getting created 
to hack GPS information (and sometimes depth finder information) into uDig.
> My initial response:
>    1. As far as I know, GDAL reads MrSID, which means one solution is
>       to serve the images through a MapServer WMS service. Then UDig
>       or any other client will be able to use them anywhere on the
>       network.
That is a good solution; due to the work we did to get a GDAL bridge 
going for uDig the next round of GeoServer will probably have MRSID as 
well; so that will be another option for the J2EE shops around.
>    1. I’d recommend installing UDig on each machine. Installing and
>       updating could be done over the network however.
>    2. What do you mean by ‘linking mobile devices’? Perhaps you could
>       be more specific?
> Deon’s subsequent query:
> Hi Gavin
> I have just been to an ESRI workshop where we discussed things like 
> ArcPad and other GPS devices linked to ArcGIS. Obviously it was very 
> detailed but my query is much more general. I would like to know what 
> functionality UDig has in terms of linking to handheld GPS’s.
Out of the box *none* :-) But there are a couple community modules on 
that topic; I think a google summer of code student hacked in that 
> For instance we are currently considering (how far we will get is 
> another issue entirely) sending our inspectors out with GPS’s and 
> having them log what they see in terms of things like address, 
> business type, land use etc. and then linking these coordinates to the 
> specific land parcel. The data could be very specific i.e. an address 
> number or perhaps even a longish comment. I’m sorry I cannot be more 
> specific but we are basically brainstorming at this stage.
No worries; the kind of thing you describe is often what people use uDig 
as a base to build from. The uDig we put up for you to download is 
really just a sample to try and interest developers; it is getting 
better and better the more developers we add to our community, but the 
focus for everyone is on these "custom" applications in which GIS is a 
small part. I think the major benifit in rolling out a custom 
application for inspectors is that you don't confuse them with a bunch 
of GIS bells and whistles that just get in the way of doing their job.
> I have played around with UDig as front-end for a while now and have 
> found it rather slow – is this the way it is or are there some tweaks 
> that I could try. Obviously I’m comparing it with ArcGIS which is 
> rather unfair but I’d just like to know.
Interesting; we have been optimizing (particularly shapefile rendering 
speed) for a while now. The comparison is not unfair; it is reality. I 
would like to know where your data is (PostGIS, ArcSDE, Shapefiles) and 
make sure you have your indexes created, and finally if you are looking 
in the data in the same projection as it is stored in? There are a bunch 
of rendering options (like transparency and anti aliasing) that you can 
turn off as well.
> Are there any other desktops other than UDig and QGis that I should 
> try. I’m not quite ready to go delving into the other database-related 
> stuff quite now and am specifically looking at smaller desktop 
> applications with some minor editing of mainly existing shapefiles and 
> using existing aerial photos as “backdrops” (therefore my query re 
> MrSid as our Tiffs are huge!
QGis is a good thing to look at; it has a single threaded design but for 
your needs it may be perfect. OpenJUMP and gvSig are also worth looking at.
> As indicated before to a certain extent I’m not comparing apples with 
> apples but currently I am experimenting trying to utilize features 
> that can/will impress the unconverted and match or even improve ArcGIS 
> functionality. My initial investigations seem to indicate that OSS 
> might not be quite ready to take over large organizational GIS 
> functions (in Ekurhuleni Metro for instance) but I am also very 
> interested in the smaller users as we have many requests from outside 
> parties who need to read shapefiles but cannot afford an ArcGIS kind 
> of application.
Right; as indicated above most of what we can get paid to build is 
specific applications that target a particular workflow. If you can 
round up interested parties that want to push uDig (or any open source 
project frankly) in the simple shapefile editor direction then please 
look at funding open source.

(As an open source project lead I would *love* to have a group of 
hackers in Africa working on this stuff; perhaps for the next FOSS4G we 
can get some hands on training time in).
> I know I sound a little vague on many fronts (and I cannot be 
> considered a techie) but I will certainly be getting into contact you 
> for more detailed stuff later if you will indulge me.

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