Method and apparatus for analyzing an image to detect and identify defects
US5815198A · kind A · utility
Inventors
Key dates
| Filing date | May 31, 1996 |
| Grant date | Sep 29, 1998 |
| Priority date | — |
| Expiry date | May 31, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30124
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The Invention includes a method and apparatus which analyzes an image of an object to detect and identify defects in the object. The present invention utilizes a scanning technique which converts a 2-D image of the object into a 1-D image, a transformation technique which extracts relevant features from the image, and a fuzzy inferencing technique which utilizes the features generated by the transformation technique to detect and identify defects. The present invention preferably includes an off-line learning process which selects the optimum transform coefficients for a given set of defects and stores the corresponding features in a rulebase. Preferably, the wavelet transform is used as the transformation technique to provide an analysis of the image which is localized in the frequency and time domains. The present invention may also include an on-line learning process when the present invention is incorporated into a manufacturing process for real time inspection of the object being manufactured. The on-line learning process attempts to nullify the effects of noise which may be associated with the image sensors being used to read the image by using a similarity function to mainta…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.