The software currently available for analytical relief shading does not generally permit local adaptations of the light direction, the simulation of aerial perspective, and other necessary techniques developed for manual relief shading. To remedy this deficiency, a program for computer-assisted relief shading has been developed that allows users to locally adapt shading characteristics, permitting seamless interactive control over the entire process. The grey values of the image are determined by a combination of aspect-based shading for steep regions, diffuse reflection for lowlands, and a bright grey tone for flat areas. Furthermore, an algorithm for the simulation of aerial perspective is presented. Tests with the program have shown that, with minimal investment of time, the quality of analytically produced shaded relief can be improved significantly. Using the proposed techniques and software presented herein, experienced cartographers can transfer their manual relief-shading knowledge and experience to the digital realm.
|Number of pages||10|
|Publication status||Published - 1 Dec 2001|