Log surface determination technique

Abstract

A log surface determination technique involves optically measuring a tree stem and accurately separating the image of the tree stem from adjacent background, determining the true surface of the stem, eliminating discontinuities or anomalies, and identifying the ends of the stem, thereby making more accurate the definition of diameter measurement planes and more accurate edges or sides of the stem for permitting a more precise evaluation of the tree stem to obtain optimal board feet yield. The tree stem is optically scanned to produce data representative of a series of adjacent optical slices through the stem, with successive optical slices of the tree stem being aligned with one another to produce a composite picture of the surface of the stem which may include a number of edges containing both the size of the stem and anomalies such as branch stubs, bark chips, etc. Through a refinement algorithm, employing an X-shaped filter, the existence of a true edge or side of the stem can be identified as contrasted to anomalies which would otherwise produce erroneous data for subsequent tree stem evaluation. Through this filtering process, once the anomalies are removed, gaps in the outline of the tree stem which result from the filtering process are filled in by an interpolation procedure based upon adjacent portions of the stem edges.