National Instruments IMAQTM 用户手册

© National Instruments Corporation

This chapter describes how to set up an imaging system, acquire and 
display an image, analyze the image, and prepare the image for additional 
processing.

Before you acquire, analyze, and process images, you must set up an 
imaging system. The manner in which you set up the system depends on the 
imaging environment and the type of analysis and processing you need to 
do. Your imaging system should produce images with high enough quality 
so that you can extract the information you need from the images.

Follow the guidelines below to set up an imaging system.

1.

Determine the type of equipment you need based on the space 
constraints and the size of the object you need to inspect. For more 
information, refer to Chapter 3, System Setup and Calibration, of the 
IMAQ Vision Concepts Manual.

a.

Make sure the camera sensor is large enough to satisfy the 
minimum resolution requirement. 

b.

Make sure the lens has a depth of field high enough to keep all of 
the objects in focus regardless of their distance from the lens. 
Also, make sure the lens has a focal length that meets your needs.

c.

Make sure the lighting provides enough contrast between the 
object under inspection and the background for you to extract the 
information you need from the image.

2.

Position the camera so that it is parallel to the object under inspection. 
If the camera acquires images of the object from an angle, perspective 
errors occur. Even though you can compensate for these errors with 
software, NI recommends that you use a perpendicular inspection 
angle to obtain the fastest and most accurate results.

3.

Select an image acquisition device that meets your needs. National 
Instruments offers several image acquisition devices, such as analog