-----Messaggio originale-----
Da: Andrea Aime [mailto:aaime@anonymised.com]Well, this is a hole in the tiff+tfw approach we're trying to
fix, that is, tfw does not provide CRS information.
A new wiki page is needed to guide people using image + tfw files.
Do you have time to write one?
I would be glad to do that. In the next days I'll menage to accomplish the task.
May I edit directly the wiki pages or have I to send a document to someone?
There are a few cases here that make us still want to have that page:
* data without CRS -> you have to provide us one (the gt2-image is
buggy in this respect)
* data with a CRS that cannot be mapped to any known EPSG code.
Here you have to choose one since the standard tells us
that we have
to advertise an EPSG code, possibly one with little
trasformation cost
compared to the native one.
* data with a CRS that can be mapped to EPSG codes, but only after a
5-10 search in the EPSG database. This happens when the
WKT does not
provide an EPSG code, but just the projection parameters.
I guess you would not want to wait for the search to be fully
performed if you already know the code, hence the lookup
SRS and the
possibility for you to input by hand.Ah, I guess I need to add a user page explaining the ins and
outs of this way of doing things. I've tried to make
Geoserver work in most situations, the result is not really
as straightforward as I'd like.
Any suggestions on how to improve it?
Well, I agree it was a good idea to have the software doing its job and reading the CRS definition from the data. But maybe the actual situation is a bit too much rigid, and not much intuitive, at least for the normal/new user (like me).
I mean: now Geoserver reads the CRS from the data, and take that as good AND the user cannot change it. The user can supply (via web admin interface) another CRS and Geoserver traslate on the fly from the "native" guessed CRS to the user chosen CRS. Right? In this way, if there is not a native CRS, the user can supply one (not sure what the gt2-image bugs can cause in this case).
What about having Geoserver reading the CRS (or at least trying to) from the data, then presenting this to the user (in the web admin interface) as a proposed (recommended, change-this-at-your-own-risk, etc.) SRID, then having the user accept the default value or specifing a different one. After having set the SRID, Geoserver should assume data are in the specified SRID (guessed or inputed from the user, it's the same). This seems much more intuitive for me.
I did some other tests, and there seems to be a problem with the Coverage Editor page (besides what I've already written about, the wrong 4326 lookup with no prj file):
- tif+tfw+prj files (EPSG in the prj: 3003)
- create CoverageStore, all ok
- create Coverage, all ok: it reads the 3003 SRID
- hit submit, apply, save, all ok
- edit the coverage configuration again, change the SRID in EPSG:26591, press submit: it doesn't update the WKT text (leave the 3003 one)
- press apply, save: on disk the info.xml reports the new SRID 26591, but the web page still shows the 3003 WKT
- press load on the web admin
- enter the Coverage Editor again: now there is the correct SRID (26591) and its WKT
Am I confused or there something wrong?
If this is a defect, I can fill a Jira issue. With this I have 3 issues to file about WCS, but Jira seems broken (at least on geoserver project) , when I hit "Create a new issue" I get this:
500 Servlet Exception
java.lang.NullPointerException
at com.atlassian.jira.plugin.webresource.JiraWebResourceIntegration.getBaseUrl(JiraWebResourceIntegration.java:42)
at com.atlassian.plugin.webresource.WebResourceManagerImpl.getStaticResourcePrefix(WebResourceManagerImpl.java:182)
at _jsp._500page__jsp._jspService(includes/decorators/stylesheettag.jsp:12)
at com.caucho.jsp.JavaPage.service(JavaPage.java:60)
at com.caucho.jsp.Page.pageservice(Page.java:570)
at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:159)
at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:115)
[...]
Cheers,
Fabio