EdgeThreshold Property

NI Vision for Visual Basic

EdgeThreshold Property

Syntax

CWIMAQQRSearchOptions.EdgeThreshold

Data Type

Long

Purpose

Specifies the minimum contrast a pixel must have in order to be considered part of a QR code cell edge.

Remarks

The lower this value, the more potential edge candidates the method will examine during the location phase. Setting this value too low will decrease the performance of the method because the method will examine too many potential edge candidates. Setting this value too high may also decrease the performance of the method by removing valid edge candidates, making location require more iterations. Setting this value too high may also cause the method to fail to identify the QR code because all edge candidates are eliminated. The default value is 30.