Improving the Representation of Large Landforms in Analytical Relief Shading

Download or read book Improving the Representation of Large Landforms in Analytical Relief Shading written by Brooke E. Marston and published by . This book was released on 2014 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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-based network 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 shaded relief image. Similar to manual relief shading, major landforms and the structure of the terrain are more clearly shown in the final shaded relief image. The presented method best highlights major landforms in terrain characterized by sharp, clearly defined ridges and valleys.