[gdal-dev] FWD: OGC seeks comment on revised GML in JPEG 2000

[Jukka Rahkonen]

Mateusz Łoskot <mateusz <at> loskot.net> writes:

> Hi,
> 
> I think this may be of interested within the GDAL community:
> 
> http://www.opengeospatial.org/pressroom/pressreleases/1965

Hi,

First time ever I tried to send feedback to OGC. Let's see if my mail went
through. I commented two issues:

1. It looks like OGC has defined that origin in georeferencing means the
centre of pixel in change number 6:
Clarification of the use of CRS and Rectified grid coverage / image
georeference with origin point (at pixel center). Is this interpretation
right and could it be expressed in some fool proof way, like
"Origin of the RectifiedGrid is placed at the centre point of the corner pixel"

2. Throughout the paper srsNames are given in two different ways. 
- srsName="http://www.opengis.net/def/crs/EPSG/0/4326"
- srsName="urn:ogc:def:crs:EPSG::4326"
In one example there is even this.
- srsName="EPSG:4326"

I believe that it means that both http and urn versions can be used but
there was not enough room in the 91 pages long document to tell that.
Perhaps the meaning is to be explicit and therefore there is a reference to
another document with number OGC 07-092r3
http://portal.opengeospatial.org/files/?artifact_id=30575
However, reading OGC 07-092r3 does not help, that document does not mention
at all that srsName="http://www.opengis.net/def/crs/EPSG/0/4326" could be
used but it knows only the urn syntax.

The same thing in with units of measures. There is a table 3 "URIs for
units-of-measure" that gives examples of how to refer to UoM and they are like
- http://www.opengis.net/def/uom/OGC/1.0/metre or
- http://www.opengis.net/def/uom/EPSG/6.3/9001

But in XML examples UoMs are expressed mostly as
- uom="urn:ogc:def:uom:EPSG::9001"

There seems to be also at least one copy-paste error in the examples:
<Envelope srsName="http://www.opengis.net/def/crs/EPSG/0/4326" 
axisLabels="Lat Long" uomLabels="deg deg" srsDimension="2">
<lowerCorner>270379.500 3942462.000</lowerCorner>
<upperCorner>518842.500 3942462.000</upperCorner>
</Envelope>

-Jukka Rahkonen-