Method and device for automatically determining the ridge lines of a variable-height area

摘要

The invention relates to a device (1) comprising: means (3) for receiving an image of a pre-determined area, containing the heights of points therein; means (8) for determining the directions of flow; means (9) for finding source points that can be used to create a binary image; means (11) for filtering the binary image; processing means (13) that can be used to obtain a set of lines formed by source points; means (15) for creating, from said set of lines, a set of sequences of segments illustrating the ridge lines of the area; and means (19) for transmitting said set of sequences of segments to user means (22).

主权项

1. Method for automatically determining ridge lines of a particular variable-height area, according to which method the following successive operations are performed automatically:
a) on the basis of an image of said area (ZO), which contains the heights of points therein, flow directions (30) are determined; b) on the basis of said flow directions (30), source points which make it possible to create a binary image (I2) are sought, a source point being a point towards which no point in its vicinity leads along said flow directions (30); c) said binary image (I2) is filtered to eliminate isolated points so as to obtain elements (31) formed of adjacent source points; d) the elements (31) thus obtained are processed so as to obtain a set of lines (32) formed of source points; and e) on the basis of said set of lines (32), a set of sequences of segments (Si) illustrating the ridge lines of said area (ZO) is created, by performing the following successive operations:
pre-processing is carried out to prepare the data received from step d) for extraction;ridge lines are extracted; andfinal processing is carried out to eliminate duplicates and preserve only the segments which are longer than an adjustable threshold length.