Evaluation Engineering - December 2008 - (Page 38)

MACHINE VISION Vision System Online Help by Tom Lecklider, Senior Technical Editor achine vision applications involve widely varying degrees of difficulty. Some are straightforward and easily handled by one of the so-called smart cameras. Smart cameras have sufficient built-in processing capabilities to perform basic image analysis tasks. Vision sensors are similar but more limited in the kinds of applications they address. Both types may provide a complete solution by integrating lighting, a camera, image processing, and camera-to-host I/O. More difﬁcult applications require some outside help unless you have experience designing and implementing machine vision solutions. Many system integrators with the necessary experience are happy to discuss possible approaches to your problem. You need a clear understanding of what must be accomplished, but you don’t have to know how to do it. This is the point at which contacting machine vision experts makes sense. W h a t a b o u t t h e l a rg e range of applications between the relatively easy and the very difﬁcult? What are your chances of handling the jobs yourself? How much online information is available? M What can you learn on your own about machine vision even if a system integrator ultimately is called in? Online Resources On many websites, the most common form of user help is a selection matrix. In most cases, these are product-oriented rather than applicationoriented. A camera selection matrix might include the sensor size, vertical and horizontal pixel resolution, frame rate, and perhaps interface type. Unless you have a reasonable level of experience in camera selection, it’s not easy to make trade-offs among a large number of parameters when presented this way. Technical notes, case studies, and white papers also can provide useful information. Not surprisingly, white papers and case studies generally deal with a company’s own technology and products. Given the expertise a company may have in something like smart cameras, you can learn a great deal about capabilities and deployment by reading a few case studies. Broader, less product-specific information is presented in a technical note. A popular topic on several sites is comparison of CMOS- and CCDbased cameras. In fact, this topic has been a popular subject for many years. Initially, CCDs were by far the technology of choice, having better dynamic range and linearity. Today, CMOS sensors have improved to the point that for many applications they offer better performance at a lower cost. Many companies publish their own online newsletters. Although this document generally is used as a marketing tool, newsletters often contain helpful The Fundamental Parameters of an Imaging System Courtesy of Edmund Optics 3 8 • E E • December 2008 www.e v al u a ti o n e n g i n e e r i n g . c o m http://www.evaluationengineering.com

Table of Contents Feed for the Digital Edition of Evaluation Engineering - December 2008

Evaluation Engineering - December 2008 Contents Editorial Product Briefing Test Software C-V Measurements Nanoelectronics Test Product Guide Company Guide Machine Vision EMC Test Index of Advertisers

Evaluation Engineering - December 2008

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