A 'Vision System' is defined as a prebuilt solution that is ready to configure and deploy, containing the sensor, processor and software. While generally used to automate manufacturing and secure product quality, the use of vision systems in non-industrial applications such as medical, traffic, sports or entertainment is becoming common.
Selecting and correctly configuring the optimal illumination setup is one of the key factors when designing a vision system. Missing image information caused by incorrect illumination makes subsequent analysis much more difficult or even impossible, as no analysis algorithm can recover information that has never been captured.
Virtually all cameras need a lens of some kind to collect the light that is scattered from the surface of an object. The lens reconstructs this scattered light as an image on a light sensitive area behind the lens, normally a CCD or CMOS sensor.
Acquisition technology has seen major changes in the last few years,
particularly with the adoption of new bus technologies. Traditional
frame grabber technology has been joined by a range of generic
interfaces such as FireWire and USB (2.0 and 3.0) along with Gigabit
The basis of all imaging software is the ability to acquire, transfer,
manipulate and interpret the pixel data output by a camera. What happens to
these images can vary from the relatively simple task of saving them to disk,
through to using them in a complex pattern recognition application.
When selecting a PC for an imaging application there are many factors
that need to considered in order to ensure that the solution chosen
delivers the performance needed, combined with both long-term
reliability and stability of supply.
Although not essential for all applications, calibrating a vision system is important if you are looking to extract data and make decisions based on measurements using real world units, such as for robot guidance.
Today 3D machine vision is most commonly used for the precise three-
dimensional inspection and measurement of complex 3D free formed surfaces, but
new fields of applications are constantly being explored.
3D inspection is one of the latest buzzwords in the vision industry. The term 3D summarises a number of totally different acquisition and evaluation techniques that are used to gain object information that could not be easily analysed using 2D camera technology.
Once you have selected the field of view you require, resolution and
image quality are the most important lens selection criteria. The lens
has to fit the resolution of the camera and the requirements of the
With a perfect lens, all rays of light from a single point on an object
plane will be focused to a single point on the image plane. Any lens
behaviour that stops this happening is classified as aberration.