Ut-battelle, Inc.

Lawrence Livermore National Security, LLC

Klaus-peter Ziock

Thomas P Karnowski

Timothy F Gee

Lorenzo Fabris

Mark F Cunningham

James Samuel Goddard, Jr

James S Goddard

Frezghi H Ghebretati, Jr

Multiple homography transformations corresponding to different heights are generated in the field of view. A group of salient points within a common estimated height range is identified in a time series of video images of a moving object. Inter-salient point distances are measured for the group of salient points under the multiple homography transformations corresponding to the different heights. Variations in the inter-salient point distances under the multiple homography transformations are compared. The height of the group of salient points is estimated to be the height corresponding to the homography transformation that minimizes the variations.

Estimating vehicle height using homographic projections

The relationship between the high energy radiation imager pixel (HERIP) coordinate and real-world x-coordinate is determined by a least square fit between the HERIP x-coordinate and the measured real-world x-coordinates of calibration markers that emit high energy radiation imager and reflect visible light. Upon calibration, a high energy radiation imager pixel position may be determined based on a real-world coordinate of a moving vehicle. Further, a scale parameter for said high energy radiation imager may be determined based on the real-world coordinate. The scale parameter depends on the y-coordinate of the moving vehicle as provided by a visible light camera. The high energy radiation imager may be employed to detect radiation from moving vehicles in multiple lanes, which correspondingly have different distances to the high energy radiation imager.

Calibration method for video and radiation imagers

In a vehicle, a single detector plane simultaneously measures radiation coming through two coded-aperture masks, one on either side of the detector. To determine which side of the vehicle a source is, the two shadow masks are inverses of each other, i.e., one is a mask and the other is the anti-mask. All of the data that is collected is processed through two versions of an image reconstruction algorithm. One treats the data as if it were obtained through the mask, the other as though the data is obtained through the anti-mask.

Dual-sided coded-aperture imager

Growing community of inventors

Clinton, TN, United States of America

Klaus-peter Ziock