Title :
System for inspecting pad-printed characters using the normalized correlation of the segmented character images
Author :
Sato, Kazuhiko ; Kan´no, Hiroshi ; Ito, Tsutomu
Author_Institution :
Sony Magnetic Products Inc., Miyagi, Japan
fDate :
28 Oct-1 Nov 1991
Abstract :
A system has been developed for checking the quality of pad-printed characters on video cassettes using digital image processing. This system can detect blurred characters, characters with missing parts, and undesirable spots. A character is divided into several segments and the normalized correlation for each segment is calculated so that the result can be reflected by small defects and becomes similar to that of visual inspection. This special inspection algorithm has also improved the inspection speed. It takes less than 1.2 s to inspect one cassette by using five high-speed image-processing boards
Keywords :
automatic optical inspection; image processing; quality control; automatic optical inspection; blurred characters; computerised picture processing; digital image processing; high-speed image-processing boards; normalized correlation; pad-printed characters; quality; segmented character images; video cassettes; Cameras; Control systems; Fluctuations; Fluorescence; Image processing; Image segmentation; Indium tin oxide; Ink; Inspection; Lighting control;
Conference_Titel :
Industrial Electronics, Control and Instrumentation, 1991. Proceedings. IECON '91., 1991 International Conference on
Conference_Location :
Kobe
Print_ISBN :
0-87942-688-8
DOI :
10.1109/IECON.1991.239047
