US 2018/0128602 A1 · MEASUREMENT METHOD, MEASUREMENT APPARATUS, MEASUREMENT PROGRAM AND COMPUTER READABLE RECORDING MEDIUM IN WHICH MEASUREMENT PROGRAM HAS BEEN RECORDED

Abstract

A phase of a specific frequency component of an image of a grid image on the surface of an object taken by a camera is found, and the location of the surface of the object is found from the phase. As a result, measurement that is strong against noise can be carried out without projecting a grid having a brightness distribution of precise cosine waves. In addition, the process is simple and can be used for the surface of a moving object. The number of pixels used for the measurement is smaller than that in the sampling moire method.

Claims10

Dependent claims

A measurement method for measuring the location of a surface of an object from an image of a grid image on the surface of the object taken by a camera, comprising the steps of:

inputting an image taken by a camera in an adjusted state where one grid period of said grid image consists of N pixels where N is an integer greater than 2;
sampling a number of sequential pixels from the inputted image;
finding a phase of a frequency component where one period consists of N pixels from the image of the sampled sequential pixels;
and
finding the location of the surface of the object from said phase.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

14/906,987Filed 30 Jun 2014

Published

10 May 2018

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01B 11/2513
By projecting a pattern, e.g. one or more lines, moiré fringes on the object: with several lines being projected in more than one direction, e.g.…
G01B 11/25
For measuring contours or curvatures: by projecting a pattern, e.g. one or more lines, moiré fringes on the object
G01B 11/254
By projecting a pattern, e.g. one or more lines, moiré fringes on the object: projection of a pattern, viewing through a pattern, e.g. moiré
G06T 7/521
Depth or shape recovery: from laser ranging, e.g. using interferometry; from the projection of structured light

Measurement method, measurement apparatus, measurement program and computer readable recording medium in which measurement program has been recorded

Life of this patent

Measurement method, measurement apparatus, measurement program and computer readable recording medium in which measurement program has been recorded

Life of this patent

Abstract

Claims10