Patent Number: 6,310,985

Title: Measuring angular rotation of an object

Abstract: A system is disclosed for determining the rotational orientation of anobject. An image of the object is digitally captured. The digital image isfiltered through an edge detection operation to enhance the edgeinformation contained in the image. The filtered image is rotated througha series of incremental angles to produce a series of rotated images. Eachrotated image is projected onto an x-axis and y-axis defined by pixel gridaxes defined by the original image. The projection of the rotated imagesproduces projected pixel counts formed by the summation of pixel valuedifferences of the x-axis and y-axis on the projected image. For eachrotated image, a score corresponding to the sum of the difference ofgray-scale values for adjacent projected pixels is computed. The scoresfor the projections of each rotated image are plotted on a score-anglegraph. A curve which includes the highest score and the neighboring nexthighest scores is interpolated to determine the peak score. The peak scorecorresponds to the scene angle of the object relative to the x-axis andy-axis defined by the original image.

Inventors: White; Raymond G. (San Jose, CA)

Assignee:

International Classification:

Expiration Date: 10/32013