Re: [Geotools-gt2-users] GIS, GeoAPI tutorial?

[Jody G. <jga...@re...>]

Hi Jesse - I am working on putting documentation onto the wiki (on and 
off when I get time) - have a good steady stream of questions is nice; 
but having people such as yourself to review the wiki pages is even 
better :-)

I don't have an example of reading a GeoTIFF file right now ... I know 
you use a the GeoTIFF format and end up with a GridCoverage at the end 
of the day... GridCoverage has an extent (the bounds of the image) and a 
coordinate reference system (which you will need to figure out what the 
points mean).

Jesse Sightler wrote:
> Is there some tutorial somewhere for those of us who are new to this 
> world of Geo APIs?  Ie, something with some nice examples of how one 
> might go about solving simple problems given some input file (say a 
> GeoTIFF file, eg)?
>
> I've been studying the code for a bit, and have slowly learned how to 
> get around my earlier issues with a NPE (it should really give a nicer 
> message when the EPSG data isn't available :) ), but I'm completely 
> new to all of this.
>
> Do the APIs provide easy ways to do things like the following:
>
>     * Find the pixel position of a given geographical coordinate? 
>       Translate that position based on scaling the image?
>
This one will be a bit harder - GridCoverage lets you sample the data at 
a specific point; I think you can figure out the number of rows and columns
>
>     * Find the distance between two pixels within the raster based
>       upon the geographical data in the underlying geotiff?
>
You can find some "distance on spheroid" methods that will tell you the 
distance between two points.
> I apologize if these are questions that get asked often.  As I said, 
> I'm a complete newbie and am trying to pick this stuff up from bits 
> and pieces on the web.  The whole terminology is pretty foreign to 
> me.  :)
It is hard to get going; especially since all this stuff deals in data 
terms and could not care less about pixels :-(

Jody