Patent ID: 8866899
Filing Date: 2014-10-21
Classification: G01N,G06T

Abstract:
1. An apparatus for identifying a defect in an electronic circuit having periodic features, the apparatus comprising: a. a camera for obtaining an image of the electronic circuit; and b. an image processing system comprising a processing unit and a memory, the image processing system being configured to: i. receive the image of the electronic circuit from the camera; ii. perform a diagonal shift of the received image of the electronic circuit by at least a diagonal size of the periodic features of the electronic circuit to produce a shifted image of the electronic circuit; iii. identify a candidate defect using the image of the electronic circuit and the shifted image of the electronic circuit; iv. compute one or more local defect-free reference images of an area of the electronic circuit using at least one selected image area containing no defects in the proximity of the identified candidate defect; and v. determine the defect in the electronic circuit using the computed defect-free reference image of the electronic circuit and the image of the electronic circuit.