Справочник Пользователя для National Instruments IMAQTM

•

FindMidLine

—Finds the line that is midway between a point and a 

line and is parallel to the line.

•

FindPolygonArea

—Calculates the area of a polygon specified by its 

vertex points.

You can make measurements based on the values obtained by meter, LCD, 
and barcode readers.

Use 

CWIMAQMeterArc.CreateFromPoints

 or 

CWIMAQMeterArc.CreateFromLines

 to calibrate a meter or 

gauge that you want to read. 

CWIMAQMeterArc.CreateFromLines

 

calibrates the meter using the initial position and the full-scale position 
of the needle. 

CWIMAQMeterArc.CreateFromPoints

 calibrates the 

meter using three points on the meter: the base of the needle, the tip of 
the needle at its initial position, and the tip of the needle at its full-scale 
position. Use 

CWIMAQVision.ReadMeter

 to read the position of the 

needle using the CWIMAQMeterArc object.

Use 

CWIMAQVision.FindLCDSegments

 to calculate the regions of 

interest around each digit in an LCD or LED. To find the area of each 
digit, all the segments of the indicator must be activated. Use 

CWIMAQVision.ReadLCD

 to read the digits of an LCD or LED.

In addition to making measurements after you set regions of inspection, 
you also can identify parts using classification, OCR, and barcode reading.

Use classification to identify an unknown object by comparing a set of its 
significant features to a set of features that conceptually represent classes 
of known objects. Typical applications involving classification include the 
following:

•

Sorting—Sorts objects of varied shapes. For example, sorting different 
mechanical parts on a conveyor belt into different bins.

•

Inspection—Inspects objects by assigning each object an identification 
score and then rejecting objects that do not closely match members of 
the training set.