Detection of objects in an object

Abstract

The invention relates to a method for detecting an object (23; 53; 104; 402, 404; 501; 603) having at least one symmetry property in the interior of the inspection object (102) based on at least a transmission image (1a; 40a; 400a; 500a; 600a ; 600b; 600c) comprising the steps of: (a) detection of edges (29, 31; 59, 65; 410a, 412a, 410b, 412b, 442, 446, 418a, 420a, 418b, 420b, 444, 448; 512a, 512b) of individual objects contained in the transmission image, and generating a corresponding edge image (1b; 40b; 400b; 500b); and (b) searching a symmetry line (27; 61; 408, 416, 511; 601a; 601b; 601c), the one in the transmission image (1a; 40a; 400a; 500a; 600a; 600b; 600c) object contained (23; 53 ; 104; 402, 404; 501; 603) having at least one symmetry property is assigned based on another with respect to the symmetry line (27; 61; 408, 416, 511; 601a; 601b; 601c) symmetrically arranged pairs of edge pixels of the edge image (1b ; 40b; 400b; 500b); wherein in step (b) to determine the line of symmetry (27; 61; 408, 416, 511; 601a; 601b; 601c) in the edge image (1b; 40b; 400b; 500b) only those edge pixels are taken into account with respect to the symmetry line (27 ; 61; 408, 416, 511; 601a; 601b; 601c) in one (in the transmission image 1a; 40a; 400a; 500a; 600a; 600b; 600c object contained) (23; 53; 104; 402, 404; 501; 603 ) to which the edge belongs, is located. The invention further relates to a device (210) for image processing having at least a processor (211) adapted for performing the method.