Справочник Пользователя для National Instruments IMAQ Vision for LabWindows TM /CVI

Use 

imaqFindLCDSegments()

 to calculate the ROI 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 

imaqReadLCD()

 to read multiple digits of 

an LCD or LED.

In addition to making measurements after you set regions of inspection, 
you can also identify parts using classification, optical character 
recognition (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.

Before you classify objects, you must train the classifier session with 
samples of the objects using the NI Classification Training Interface. 
Go to Start»Programs»National Instruments»Classification Training 
to launch the NI Classification Training Interface.

After you have trained samples of the objects you want to classify, use the 
following functions to classify the objects:

1.

Use 

imaqReadClassifierFile()

 to read in a classifier session that 

you created using the NI Classification Training Interface.

2.

Use 

imaqClassify()

 

to classify the object inside the ROI of the 

image under inspection into one of the classes you created using 
the NI Classification Training Interface.

3.

Use 

imaqDispose()

 

to free the resources that the classifier 

session used.