Generation of arbitrary moire contours for automated inspection

Autor: Joel H. Blatt, Bernard R. Gilbert
Rok vydání: 1994
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.169359
Popis: We have developed a method of creating arbitrary moire patterns from any arbitrary diffusely reflecting object that does not require any physical grating fabrication. The moire patterns can be made in any form, from equal depth contours, to error maps, to any pattern that would aid in automated or machine aided inspection or sorting. We first generate the desired output moire pattern, either in the computer or by capturing the image of the desired pattern. We then use a Michelson interferometer to generate and project variable spatial frequency gratings on the perfect target and capture the image of these distorted gratings. We next compute the shape of a filter (transmission or viewing) grating that would cause the desired output from the perfect target input. The computer filter shapes are then converted to NTSC composite video and mixed with the video signal from the target camera. If the target seen matches the perfect target, the desired moire output pattern is produced.
Databáze: OpenAIRE