Monday, September 8, 2008

Learn more about GigE Line Scan

Line scan applications are an interesting subset of the machine vision universe, and if you’ve ever taken a close look you’ll know that they are not straightforward. (For the newbies amongst you, a line scan camera is much like a scanner or fax machine: it’s a single line camera, the full image being produced by ‘scanning’ across the surface to be examined and then assembling the lines together.)

A particular issue with line scan is cost. Most modern line scan cameras use the CameraLink protocol, which is fast but needs special framegrabbers and cables, and these are not cheap. Conversely, one of the selling points of Gigabit Ethernet (GigE) is low cost, due to CAT5/6 cabling and inexpensive network cards.

So a GigE line scan camera would seem to make sense. However, there are some issues to be addressed, in particular, speed and triggering. These points, and more, are covered in a white paper I recently unearthed on the Basler web site, “
Gigabit Ethernet and Line Scan Cameras – do they really fit?” (You’ll need to register to access the 13 page paper.)

The paper focuses principally on the Basler ‘
runner’ series of cameras, but there’s enough technical detail in the paper to make it relevant to anyone exploring a line scan application. If you want to do some comparison shopping, I suggest also checking out the Spyder 3 family from Dalsa.

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