Algorithms to reconstruct digital elevation map(DEM) from elevation contour is widely used in many applications. In the process of designing a 3D terrain visualization program

where only elevation contour map is available

a new method

region intra interpolation algorithm

was proposed. It utilizes the structural features of elevation contour images

that is

image is partitioned into many regions by elevation contours and each region is only bound to at most 2 elevation values. Therefore each point inside this region can be calculated as a linear interpolation from the two boundary values. The problem then turns into finding the two shortest distances to its bounding elevation contours. Fast realization is also given out

and this speed up also achieved by special design utilizing elevation contour structures to save time on searching for the closest points. Compare with current algorithm like Quadrant Search algorithm

which is design based on a model of random distributing of known value

it shows good performance on both speed and accuracy.