TOPONYMS 26th International Cartographic Conference August 25-30, - PowerPoint PPT Presentation

TOPONYMS 26th International Cartographic Conference August 25-30, 2013 | Dresden Germany PLACEMENT ON WEB MAPS analysis with proposed solutions University of Zagreb Robert Župan and Stanislav Frangeš Faculty of Geodesy rzupan@geof.hr sfranges@geof.hr Croatia

Presentation content 2 Introduction  Common errors of label placement  Assumption and rules  Research process  Research findings  Conclusion and additional research 

Introduction 3 Geographic names Map labelling –   are the heritage of attaching text material and (toponyms) to spiritual culture of geographic a people, and the features set of all toponyms Features must  makes heritage of be labelled to all mankind convey information.

Problem Definition 4 The Map Label Placement Problem Placing map feature labels  Legibly  Without overlap (features / other labels)  Maintaining visual association between features  and their labels

Map without toponyms 5 Maps without  toponyms or their labels give little information The same holds  for charts and graphs

Common errors of label placement for some most popular and global web map servers 6 Google Earth and common errors of label placement.(left fig. – shows overlaps and the right fig. shows duplicate toponym)

Common errors of label placement for some most popular and global web map servers 7 Left – Google Earth with many overlaps with all layers turned on. Right – Google Maps with different label generalization degree between Slovenia and Croatia.

Common errors of label placement for some most popular and global web map servers 8 Ask Maps web map service with map from Nokia and Microsoft and their misrepresentation and toponym visualization.

Common errors of label placement for some most popular and global web map servers 9 Large scale map in Openstreetmap and some toponyms are shown on the map but some are not visible until zooming in although there is enough space?

Two possibilities 10 Label Size Maximization   Maximize the size of the placed labels  The labeling has to be complete Label Number Maximization   Maximize the number of placed labels  Labels have fixed size Most literature focuses on Label Number  Maximization, so will this presentation

Three kinds of labels 11 Town 1 Town 3 Town 2 Town 4 Straight, horizontal Curved name Curved name with name spacing between characters

Assumptions 12 toponyms related item or coordinate (oikonyms, oronyms) and  toponyms following the line (oronyms, regionyms, territoryonyms,  hydronyms) toponyms inside the closed polygon or an area that provide  information about the that area (regionyms and territoryonyms or the names of national parks, military training grounds, etc.) there is a hierarchy showing the various types of toponyms  according to the criterion such as the type of toponyms, the importance of objects for which provide attribute information, categorization of subspecies of toponyms, color, font size of toponym, etc. Hierarchy is needed due to the significance of one kind of toponym over the other and automatic decision on the choice of toponym placement, as one of the processes of map generalization.

Elastic labels 13 According to first assumption, solution is:

Proposal for geometric solution 14 How to represent a rectangle? X 1 <X 2 , Y 1 <Y 2 , and so forth.

Horizontal collision detection 15 4 cases for collision detection

Vertical collision detection 16 4 cases for collision detection

Collision detection 17 No edges overlap, but still a collision for map label of happens whenever X1 ′ < X1 and X2 ′ toponyms. This case > X1.

Collision detection 18 Except in that special case, a collision only exists if there is both a vertical and horizontal collision.

Possible rectangle movements? 19 Sliding label presenting possible positions for toponym, software choice for priority placement, and priorities for label placement according to different authors.

Detection of the intersection of lines and rectangle 20 Test of collision for moving rectangles (left) and case with no collision in final position although there is intersection.

Detection of the intersection of lines and rectangle 21 Case where paths do not intersect

Detection of the intersection of lines and rectangle 22 Paths of rectangle r1 and r2 intersects without collision at the final point.

Detection of the predicted trajectory 23 r2 is below r1 when the left edge of r1 is collinear with the right edge of r2 so r1 and r2 do not collide

Detection of the predicted trajectory 24 r2 is initially to the left of r1 and finishes below and to the right of A, colliding with r1 along the way.

Using rectangles and rhombs depending on the type of letters 25 Collision prediction along curve or trajectory approximating letters with rectangulars or rhombs.

Using rectangles and rhombs for overlap detection

Conclusions 27 The overlap of toponym with other cartographic  objects and map content in this case is been ignored, though it also must be taken into account New algorithmic framework for fast and consistent  labelling To be tested how the proposed model behaves in the  real computing server environment.

TOPONYMS 26th International Cartographic Conference August 25-30, 2013 | Dresden Germany PLACEMENT ON WEB MAPS analysis with proposed solutions THANK YOU FOR YOUR ATTENTION! University of Zagreb Robert Župan and Stanislav Frangeš Faculty of Geodesy rzupan@geof.hr sfranges@geof.hr Croatia