An advanced processing method of ECT images based on defect-orientations

Abstract

This paper presents a novel procedure for eddy-current image processing based on defect-orientations. First, nonlinear filtering technique is used to eliminate the noise and offset component in the ECT signals keeping the shape of defect-origined signals. Then the direction finding and the pattern matching methods are carried out to find the position of the defect with a specific direction. Based on the derived information, the classification of defects and image synthesis are carried out. Through an application to images derived from samples having defects in various orientations, the effectiveness of the proposed method is verified.