A timely detection of a coated board streak defect in subsampling conditions using monochrome vision system

This paper presents a study of an important improvement in an already installed monochrome vision system for detection of defects during coated board manufacture. This improvement allows the inspection system to detect targeted defect in subsampling conditions (i.e. Nyquist theorem is not satisfied). This improvement is accomplished entirely in the image processing software without the need for additional changes in the vision hardware. Processing software is optimized for SIMD instruction set requiring no improvement in the processing hardware. Results obtained by the use of this improved algorithm provide real time detection of the targeted defect that in turns enables elimination of the waist coated board.