Perceptual Problems in Analyzing Industrial Radiographs

Abstract

Given recent advances In Image processing and analysis techniques, It seems that It should be within the state of the art to perform automatic analysis of Industrial radiographs to locate defects in manufactured Items. However, human inspectors are routinely able to detect certain subtle defects that are beyond our current capabil ltles in Image processing. This paper describes a specific radiographic inspection problem (analysis of the filler in an artillery shell), indicating the difficulties that arise in trying to detect subtle flaws, and especially flaws close to material boundaries. The relationships between human perception and the computer algorithms are indicated, and unexpected differences are pointed out (for example, the boundary determined by the human observer differs from the boundary position determined by most algorithms using a change of intensity criteria).