Correlation methods of identifying defects in imaging devices

Details Correlation methods of identifying defects in imaging devices Correlation methods of identifying defects in imaging devices

1993-03-25

1994-11-01

Razavi, Michael T.

Image analysis

Histogram processing

For setting a threshold

382 42, 382 8, G06K 964

Patent

active

053613074

ABSTRACT:
An automated system for determining artifacts in images indicating defects in an imaging device being tested employs a constant radiation source which supplies radiation of spatially uniform intensity to the imaging device to be tested. The imaging device then creates a flood image A.sup.(0). A region of interest (ROI) mask means for all pixel values of flood image A.sup.(0) sets values to zero outside of the imaging devices field of view to produce a flood image A.sup.(1). An image normalization means normalizes flood image A.sup.(1) to have an average value of zero producing a normalized flood image A. A correlation means performs an autocorrelation of normalized flood image A to produce a correlation field which is then masked to select portions of the correlation field. The correlation values of the selected regions are summed, the squares of the correlation values are summed and the resulting sums are normalized for mask shape and flood image intensity to determine and quantify the presence of specific artifacts. These normalized summed values may be compared to predetermined thresholds to determine if the artifacts have a magnitude above an acceptable level. Based upon the results of the comparison, a corrective action may be taken such as removing the imaging device from a manufacturing line or adjusting the imaging device and retesting it.

REFERENCES:
patent: 3278899 (1966-10-01), Shelton, Jr. et al.
patent: 4228420 (1980-10-01), Fenimore et al.
patent: 4322808 (1982-03-01), Weiss
patent: 4360797 (1982-11-01), Fenimore et al.
patent: 4589140 (1986-05-01), Bishop et al.
patent: 4794531 (1988-12-01), Morishita et al.
patent: 4924875 (1990-05-01), Chamoun
patent: 4993823 (1991-02-01), Schaffer, Jr. et al.
patent: 5007101 (1991-04-01), Imahashi et al.
patent: 5036857 (1991-08-01), Semmlow et al.
patent: 5221834 (1993-06-01), Lisson et al.
patent: 5224176 (1993-06-01), Crain

Affiliated with

Also associated with

Rating

Correlation methods of identifying defects in imaging devices does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Correlation methods of identifying defects in imaging devices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Correlation methods of identifying defects in imaging devices will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1807199