Tuesday, June 5, 2012

What’s driving higher bandwidth camera interfaces

Notice how there’s no question mark at the end of this post’s title? That’s because it’s not a question.

I recently came across a press release regarding a new 12.7Mp image sensor from OmniVision. (The press release was on the Optics.org website.) With pixels that, by my reckoning are about 2 microns square, this is capable of 24fps at full resolution. Now you don’t need me to tell you that that’s a whole lot of data bits for a poor old framegrabber to handle.

Of course, I can’t say that this particular piece of silicon will end up in a machine vision camera, but I’m sure OmniVision will not be alone in developing such sensors. And knowing what you vision inspection folks are like, as soon as you’re offered more pixels you’ll take them, and at the full frame rate. After all, Adimec demo’d a 25Mp camera running at 32fps at the Vision Show last month.

So that’s why we need these new interfaces like CoaXpress and HSLink.

1 comment:

Mike Miethig said...

Bandwidth certainly is a driver to move to better ways of data transfer, but not the only one. DALSA's HSLINK has been successfully deployed for about 2 years and forms the foundation of AIA's Camera Link HS (CLHS), released at the Boston show this past May. The 16 GBytes/sec of data transfer wasn't the only motivation considered by the committee. CLHS ensures data reliability using small FPGA based resend buffers, support for frame by frame camera control to fully exploit CMOS sensor technology, low latency bidirectional GPIO needed for system interface, future proof design through off the shelf components and adaptable to different physical layers as demonstrated by the 3 Gbps and 10 Gbps implementations. Fiber optic cabling enables long distance, small size and high bandwidths. As you mentioned, high data bandwidths are difficult to process and CLHS enables parallel processing implementations, while the receiving frame grabber can perform image processing to reduce the host loading. So there is more than just bandwidth increase in the new interfaces.
Mike Miethig, CLHS Chair, Technical Manager, Teledyne DALSA