US 2007/0183666 A1 · Method utilizing intensity interpolation for measuring edge locations in a high precision machine vision inspection system

Abstract

A method for operating a video tool to perform precision edge detection in an image. The method includes determining estimated image intensity values corresponding to positions along a straight line aligned with a defined scan line orientation. The location of an edge point along the straight line is determined based on the estimated intensity values and their positions along the straight line. The method reduces sub-pixel orientation-dependent variations that may otherwise be present in edge measurements. Intensity values may be estimated by interpolating between nearest neighbor image pixel intensity values. When positions along the straight line are chosen to coincide with a pixel row or column, the interpolating may be linear interpolation between the intensities of just two adjacent pixels.

Claims17

Dependent claims

A method for determining the location of an edge feature in an inspection image of a workpiece acquired by a machine vision inspection system, the method comprising:

a) identifying an edge feature included in the image;
b) defining a scan line orientation to be used for determining the location of at least one edge point of the edge feature;
c) determining a plurality of estimated image intensity values corresponding to positions along a straight line that is aligned with the defined scan line orientation;
and
d) determining the location of the edge point along the straight line based on the plurality of estimated image intensity values and their corresponding positions along the straight line.

2 more elements

A video tool for determining the location of an edge feature in an inspection image of a workpiece acquired by a machine vision inspection system, the video tool comprising:

a graphical user interface edge-identifying element positionable on a display of the image to identify an edge feature included in the image;
means for defining a scan line orientation to be used for determining the location of at least one edge point of the edge feature;
and
an edge point locating routine that comprises:
instructions that control the machine vision inspection system to perform operations for determining a plurality of estimated image intensity values corresponding to positions along a straight line that is aligned with the defined scan line orientation;
and
instructions that control the machine vision inspection system to perform operations for determining the location of the edge point along the straight line based on the plurality of estimated image intensity values and their corresponding positions along the straight line.

4 more elements

Dependencies are inferred from the claim text.

Method utilizing intensity interpolation for measuring edge locations in a high precision machine vision inspection system

Life of this patent

Method utilizing intensity interpolation for measuring edge locations in a high precision machine vision inspection system

Life of this patent

Abstract

Claims17