Tuesday, March 26, 2013

How to acquire spectral data

When you think about it, monochrome cameras are pretty crude devices. All they do is collect photons, with no regard for the wavelength of each one. Wouldn’t it be cool if a camera could sort the incoming photons into wavelength “buckets”?

Of course, that’s what a color camera does, using Red, Green, and Blue filters to ensure only a narrow range of wavelengths reach each pixel. The software has to figure out exactly what color was seen, interpolating between what was captured.

Hyperspectral imaging takes this further, enabling wavelength “slices” to be captured and analyzed. The concept has been around for some years, but to date the hyperspectral imagers I’ve seen have all been rather clunky, not to mention, expensive.

Imec and Adimec are attempting to change that, as described in these two posts on the Adimec blog, “Imec demonstrates a compact, low cost, fast hyperspectral imaging solution, part 1” and the follow up “Part 2”. There’s also a link to video demo, but you’ll have to read the Adimec posts to get to that.

I said before that color imaging is really hard. (“Why color machine vision is really difficult”) and it might seem that more spectral “channels” will make it harder, but I think the opposite is true. With less need to interpolate, we’ll be better able to zero in on the specific color we want, always assuming we can get the lighting right.

1 comment:

Anonymous said...

Specim has been doing this for years: http://www.specim.fi/index.php/products/industrial