Annotating WMS with XIMA(How to scribble on your map)

Ian TurtonCentre for Computational

GeographyUniversity of Leeds

i.turton@geog.leeds.ac.uk

Summary

• What?

• Why?

• How?

What is Annotation?

1. The act or process of furnishing critical commentary or explanatory notes.

2. A critical or explanatory note; a commentary.

• In geography often refers to adding a note to a map

Why Annotate?

• Draw attention to a point of interest

• Communicate • Collaborate• Summarise• Highlight patterns, similarities

/differences

Open Standards

• Availability– Open Standards are available for all to

read and implement.

• Maximize End-User Choice– Open Standards create a fair,

competitive market for implementations of the standard. They do not lock the customer in to a particular vendor or group.

Requirements

• Annotations…– Are independent features– Must annotate something– Often point to a spatial subset of an

image– May link to many maps or images– May have different shapes on different

maps– May have rich content– May have properties

Xima history

• 2001 – initial version – OGC-01-019

• 2004 – GML based version – OGC-04-034

• 2005 – GML in JPEG 2000 for Geographic Imagery (GMLJP2) – OGC-05-047

Xml IMage Annotation (XIMA) version 1

• Allows users to draw points, lines and polygons on to an image (WMS maps are images).

• User can attach text, images, video, URLs to the geometry.

• The xima representation can be stored on a server and passed to other users.

• A xima aware client can allow users to access the content of the annotations.

Annotated Map

Types of Annotation version 2

• Label• Point of Interest• Region of Interest• Feature of interest

Label

<Label><gml:position> <gml:Point srsName = “..”>

<gml:pos>200 200</gml:pos>

</gml:Point> </gml:position> <labelValue>Forest

Fires</labelValue></Label>

Point of Interest

<PointOfInterest> <gml:position> <gml:Point> <gml:pos>100

100</gml:pos> </gml:Point> </gml:position> <labelValue>fire source</labelValue></PointOfInterest>

Fire Source

Region of Interest

<RegionOfInterest> <gml:extentOf> <gml:Polygon srsName="#epsg4326"> <gml:exterior> <gml:LinearRing> <gml:coordinates>0,0 100,0 100,100

0,100 0,0</gml:coordinates> </gml:LinearRing> </gml:exterior> </gml:Polygon> </gml:extentOf> <labelValue>fire impact region</labelValue> <indicatedBy> <Arrow> <start> <gml:Point> <gml:pos>-50 -50</gml:pos> </gml:Point> </start> <end> <gml:Point> <gml:pos>0 0</gml:pos> </gml:Point> </end> </Arrow> </indicatedBy></RegionOfInterest>

Fire Impact Area June 2003

Feature of Interest

<FeatureOfInterest><gml:position><gml:Point><gml:pos>155 160</gml:pos></gml:Point></gml:position><labelValue>forest

road</labelValue><gml:featureMember

xlink:href="#p1"/></FeatureOfInterest>

Feature Database (e.g. OGC WFS)

Feature pointer

Fire Access Road

Simpler implementation

• No need for specialist clients or servers

• GML features stored in transactional WFS

• Any WFS client can now display annotations.

Annotation for jpeg2000

• Splits the annotation into– Pointer

• A GML curve

– Content• A label or image

– Annotates• GML geometry

Specialised Annotation elements

• PointOfInterest• CurveOfInterest• RegionOfInterest• FeatureOfInterest

• Can be styled using gml:defaultStyle or SLD

Conclusions

• Annotating maps and images is a good thing.

• XIMA is not yet a standard but its getting there.

• Watch this space.