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

After you learn the calibration information, you can save it so that you 
do not have to relearn the information for subsequent processing. Use 

imaqWriteVisionFile()

 to save the image of the grid and its associated 

calibration information to a file. To read the file containing the calibration 
information use 

imaqReadVisionFile()

. Refer to the Attach 

Calibration Information section of this chapter for more information about 
attaching the calibration information you read from another image.

Now that you have calibrated your setup correctly, you can 
apply the calibration settings to images that you acquire. Use 

imaqCopyCalibrationInfo()

 to attach the calibration information of 

the current setup to each image you acquire. This function takes in a source 
image containing the calibration information and a destination image that 
you want to calibrate. The destination image is your inspection image with 
the calibration information attached to it.

Using the calibration information attached to the image, you can accurately 
convert pixel coordinates to real-world coordinates to make any of the 
analytic geometry measurements with 

imaqTransformPixelToRealWorld()

. If your application requires that 

you make shape measurements, correct the image by removing distortion 
with 

imaqCorrectImage()

.

Correcting images is a time-intensive operation.

A calibrated image is not the same as a corrected image. Because 
calibration information is part of the image, it is propagated throughout the 
processing and analysis of the image. Functions that modify the image size, 
such as an image rotation function, void the calibration information. Use 

imaqWriteVisionFile()

 to save the image and all of the attached 

calibration information to a file.