Cost surface

To establish a cost surface according to an image’s propagation algorithms, a friction value is attributed to each pixel according to the ‘cost’ of the crossing it presents. The shift from one pixel to another totals up the costs attributed to the pixels traversed. The cost could depend on the distance, if a pixel represents 100 metres, traversing 10 pixels would represent a cost surface of 1 kilometre. But this cost could also depend on other factors, such as the time of the crossing, the energy cost, or the environmental cost depending on the themes studied. A cost surface is used for propagation algorithms.