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Grid Coding Technique For Extraction Of Curvature Of Objects In Machine Vision Applications

IP.com Disclosure Number: IPCOM000077796D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Penningston, KS: AUTHOR [+2]

Abstract

If a grid coded picture is obtained by projection of spatially modulated light, for example. grid projection or laser scanning. and recording is performed off-axis, then measurement of the rate of change of spatial frequency across the encoded picture immediately gives a measurement of measurement of the local curvature across objects in the field of view. This process can be performed readily in a computer and might be amenable to optical processing.

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Grid Coding Technique For Extraction Of Curvature Of Objects In Machine Vision Applications

If a grid coded picture is obtained by projection of spatially modulated light, for example. grid projection or laser scanning. and recording is performed off- axis, then measurement of the rate of change of spatial frequency across the encoded picture immediately gives a measurement of measurement of the local curvature across objects in the field of view. This process can be performed readily in a computer and might be amenable to optical processing.

Projection of a linear grid or square grid will yield curvature directly from calculation of the rate of change of frequency while other forms of grid, for example, zone plate, would require allowances to be made in the calculation for the rate of change of frequency of the projected grid. This latter modification would be relatively simple in practice. Higher derivatives can be measured to obtain rate of change of curvature, etc., which are important factors in determination of the shape of objects within the field of view.

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