METHOD FOR ANALYZING PROPERTIES OF A MOVABLE WOOD OBJECT, SUCH AS e.g. A TREE TRUNK

摘要

PCT No. PCT/FI97/00132 Sec. 371 Date Oct. 30, 1998 Sec. 102(e) Date Oct. 30, 1998 PCT Filed Feb. 27, 1997 PCT Pub. No. WO97/32199 PCT Pub. Date Sep. 4, 1997A method for determining the properties of a log, in which a moving log is radiographed by at least more than one X-radiation source, and the radiographic information is received by a detector array measuring radiation. Stemwood and knots of the log are calculated by a principle which is based on a known geometry and density of stemwood and knots. After measurement, the effect of stemwood in radiographic projections, and hence the analysis for locating knots, is eliminated by filtering. The knot mass is then converted from radiographic projections into volumetric elements of a cylindrical coordinate system and, from the value of each volumetric element, an evidence value representative of the presence of a knot in the element is derived. The evidence values of mutually associated elements are then combined, thus producing an aggregate evidence value which permits the knots to be located.