Tuesday, December 20, 2011

Aspect ratios and wine bottles

Despite all the growth, machine vision is still a niche industry. We’re not big enough to have the semiconductor guys make sensors just for us (leaving the linescan sub-niche out of the discussion,) so instead we have to make do with what’s churned out for consumer applications. Most of the time this isn’t a problem, but there are times when I find I’m throwing away a whole bunch of pixels.

Example? Well imagine viewing a wine bottle from the side. This has an aspect ratio something like 16:4 so to get the whole thing on a typical 16:9 aspect ratio sensor I have to include a whole lot of empty space in my image. Wouldn’t it be useful to have a long thin sensor?

Well, while I was reading up on Ximea’s USB3 cameras I spotted such a thing. Their sexily-named MQ022MG-CM has a CMV2000 sensor of 2048 x 1088 pixels. Now this sensor may be used by other camera vendors too, I haven’t bothered looking. It just struck me, while downing a glass of merlot, that long, thin sensors would be a useful thing to have.


Anonymous said...

Sick Ranger has sensor size 1536*512, even better for wine bottles if you're worried about unused pixels.

Brian Durand said...

I've been hearing a lot of good things about the new sensors from CMOSIS. Basler offers two cameras based on the CMV2000 sensor. The GigE version has been popular, but is limited to 50 full frames/second. The CameraLink version can transmit a whopping 340 frames/second.

The Sick Ranger mentioned does have an interesting aspect ratio -- ideal for 3D laser triangulaion with the built-in processing. But very expensive for a standard 2D project.