Cartographic Relief Presentation

This design paper presents new guidance for creating map legends in a dynamic environment. Our contribution is a set ofguidelines for legend design in a visualization context and a series of illustrative themes through which they may be expressed. Theseare demonstrated in an applications context through interactive software prototypes. The guidelines are derived from cartographicliterature and in liaison with EDINA who provide digital mapping services for UK tertiary education. They enhance approaches tolegend design that have evolved for static media with visualization by considering: selection, layout, symbols, position, dynamismand design and process. Broad visualization legend themes include: The Ground Truth Legend, The Legend as Statistical Graphicand The Map is the Legend. Together, these concepts enable us to augment legends with dynamic properties that address specificneeds, rethink their nature and role and contribute to a wider re-evaluation of maps as artifacts of usage rather than statements offact. EDINA has acquired funding to enhance their clients with visualization legends that use these concepts as a consequence ofthis work. The guidance applies to the design of a wide range of legends and keys used in cartography and information visualization.

/pdf/rethinking-map-legends-with-visualization-4jozw66wfp.pdf

Rethinking Map Legends with Visualization

Relief shading is the most common type of cartographic relief representation for print and digital maps. Manual relief shading results in informative and visually pleasing representations of terrain, but it is time consuming and expensive to produce. Current analytical relief shading can be created quickly, but the resulting maps are not as aesthetically appealing and do not show landscape features in an explicit manner. This article introduces an automated digital method that produces shaded relief with locally adjusted illumination directions to simulate the techniques and cartographic principles of manual relief shading. Ridgelines and valley lines are derived from a digital terrain model, vectorized, and used in a diffusion curve algorithm. A graph analysis generalizes the lines before using them for diffusion curve shading. The direction of illumination is adjusted based on the spatial orientation of ridgelines and valley lines. The diffusion curve shading is combined with standard analytical relief shading to create a final diffusion relief shading image. Similar to manual relief shading, major landforms and the structure of the terrain are more clearly shown in the diffusion relief shading. The presented method best highlights major landforms in terrain characterized by sharp, clearly defined ridges and valleys.

http://cartography.oregonstate.edu/pdf/2015_Marston_Jenny_ImprovingTheRepresentationOfMajorLandformsInAnalyticalReliefShading.pdf

Improving the representation of major landforms in analytical relief shading

Maps with coloured relief shading, modulated by elevation and by exposure to illumination, present topography in a particularly vivid and descriptive manner. Carefully modulated illumination and shading shown in continuous colour tones simulate the third dimension of topography, helping map-readers to conceive more easily the terrain's important landforms. Since the end of the 19th century, cartographers have developed a wide variety of colour schemes. The first part of this paper illustrates the graphical and technical developments of the past, leading to Swiss-style coloured relief shading; the second part presents a new computer-based method for colourizing grey-shaded relief inspired by classic colour schemes. The method uses a colour look-up table and a digital elevation model. The colour look-up table has colours for all combinations of initial grey values and terrain elevations. It is constructed from interactively placed colour reference points.

https://cartography.oregonstate.edu/pdf/2006_JennyHurni_SwissStyleShading.pdf

Swiss-Style Colour Relief Shading Modulated by Elevation and by Exposure to Illumination

In economy, society and personal life map-based interactive geospatial visualization becomes a natural element of a growing number of applications and systems. The visualization of 3D geospatial information, however, raises the question how to represent the information in an effective way. Considerable research has been done in technology-driven directions in the fields of cartography and computer graphics (e.g., design principles, visualization techniques). Here, non-photorealistic rendering (NPR) represents a promising visualization category – situated between both fields – that offers a large number of degrees for the cartography-oriented visual design of complex 2D and 3D geospatial information for a given application context. Still today, however, specifications and techniques for mapping cartographic design principles to the state-of-the-art rendering pipeline of 3D computer graphics remain to be explored. This paper revisits cartographic design principles for 3D geospatial visualization and introdu...

Cartography-Oriented Design of 3D Geospatial Information Visualization – Overview and Techniques

On topographic mountain maps, cliff drawings are among map elements that are most difficult to produce. However, they belong to some of the most spectacular representations on maps. This paper gives a short historic overview of the development of cliff drawing and describes the most common styles of cliff representations. New techniques are presented in detail for the generation of simplified ridge-line representations in an entirely digital and effective manner. The paper shows examples of mountain maps produced using this semi-automated method and suggests further developments. Sur les cartes topographiques de montagne, les rochers figurent parmi les elements les plus difficiles a reproduire, mais aussi parmi les representations les plus spectaculaires. Cet article propose une vue d'ensemble de l'historique de la representation de rochers et decrit les differents styles de dessins les plus couramment utilises. De nouvelles methodes numeriques extremement efficaces, permettant la generation d'une represe...

Digital cliff drawing for topographic maps; traditional representations by means of new technologies

Scree patterns are an important element of mountain maps in Swiss style. The size and density of scree dots vary with the exposition towards a source of illumination, which makes the dots extremely labour intensive to map without specialized algorithms. This paper identifies design principles for the symbolisation of scree fields on mountain slopes and presents a digital method for the quick placement of dot symbols requiring only minimal interventions by a cartographer. When digitally produced scree is combined with a shaded relief and a rock drawing, the terrain appears as a continuous three-dimensional surface to the reader. The described method is implemented in Scree Painter, a specialized free open-source software application. Scree patterns produced with Scree Painter match the quality standards of manually generated scree representations.

Scree Representation on Topographic Maps

Interactive Analytical Shading and Cliff Drawing: Advances in Digital Relief Presentation for Topographic Mountain Maps

title/>Patterns consisting of point symbols are commonly applied to symbolize land cover. Tree symbols, for example, indicate forested areas; small irregular dots show quarries and pits; or regular line symbols represent a vineyard. This paper presents an automatic method for synthesizing patterns consisting of one or more point symbols. Symbols of varying sizes or graphical appearance can be combined according to user-defined ratios. The automatic method generates patterns of regularly or irregularly distributed symbols. It ensures that symbols do not overlap and do not graphically conflict with other map features. The method has been implemented in a free plug-in for the Adobe Illustrator vector graphics editor.

http://cartography.oregonstate.edu/pdf/2010_Jenny_etal_PointPatternSynthesis.pdf

Point Pattern Synthesis

Proportional symbol maps are frequently used to represent numerical data. Commonly used symbols are squares or circles that are area-proportional to the numerical values. Proportional-symbol mapping is included in most geographic information systems (GIS) and is frequently used in digital atlases or Web mapping engines. Graduated symbols are simple for the map author to generate and easy for the reader to understand. However, if the reader is to accurately associate the symbol size on the map with the underlying numerical value, a carefully designed legend is essential. To link a symbol with a numerical value, the map reader mentally positions the symbol in the legend and estimates the value from the symbols shown in the legend. To reduce the associated estimation error, a legend should have the following qualities:

Ernst Hutzler

Papers

Digital cliff drawing for topographic maps; traditional representations by means of new technologies

Scree Representation on Topographic Maps

Interactive Analytical Shading and Cliff Drawing: Advances in Digital Relief Presentation for Topographic Mountain Maps

Point Pattern Synthesis

Self-Adjusting Legends for Proportional Symbol Maps