Abstract
A practical experiment for producing a contour map automatically from aerial stereo photographs using a drum scanning micro densitometer and a general purpose computer is described. The procesure is based partly on the Kreiling's method, and partly on the Konecny's method.
Among a sequence of procesures for automatical contour drawing, this paper contains photo digitizing, calibration of the image coordinate system using 4 fiducial marks, and automatical relative orientation using 2-dimensional image correlation. And following procesures, that is, digital rectification, production of grid elevation files using 1-dimensional image correlation, and contour map drawing will be discussed in the subsequent paper.
Some remarks obtained by the experiment are:
1) A drum scanning micro densitometer caused considerable irregular deformations in the image, which might not be tolerable from a photogrammetric point of view.
2) In the test of automatical relative orientation using 2-dimensional image correlation technique, when high contrast points are selected as the orientation points on the left image, the homologeous points were capable of being searched with higher precision than when one identified the homologeous points on the image printed with a line printer by eye-sight.
3) However, in the case that orientation points were given arbitrarily on the left image, the homologeous points in the mountainous region could not be searched at all.
