Physical position noise for CCD chip for more resolution - Page 1
Forum section: electronics / general

author: daqq
author_rank: Super Contributor
timestamp: July 23, 2015, 06:56:40 pm
content: Hi guys,I've been thinking: If you vibrated a CCD chip randomly by a small amount (say, 0.5 of its pixel) in both the X and Y direction, could this be used to add positional noise to the chip, then captured full frames randomly, shouldn't it be possible through some clever math to achieve some spacial equivalent of what you get with dithering for an ADC - essentially gain a higher spacial resolution?If you just have a stationary CCD chip you can sample all you want, you will still be looking at the same points. But with some small vibration device (seeing as you have point sizes of several um these days, a MEMS vibration thingie on the PCB with the CCD chip should do it) you should be able to actually shift the point of view for each pixel, adding some dithering.Thanks,David

author: lukier
author_rank: Unknown
timestamp: July 23, 2015, 07:58:22 pm
content: It is already therehttps://en.wikipedia.org/wiki/SuperresolutionAnd instead of vibrating the sensor you can just move the camera, run your favorite multi-view stereo algorithm to estimate the poses and do the same:https://www.robots.ox.ac.uk/~vgg/publications/2003/Capel03/capel03.pdf

author: Someone
author_rank: Super Contributor
timestamp: July 23, 2015, 11:29:57 pm
content: http://image-sensors-world.blogspot.com.au/2014/11/active-pixel-color-sampling-story-goes.htmlSome maths as to why its not such a great idea.

author: miguelvp
author_rank: Super Contributor
timestamp: July 24, 2015, 12:59:55 am
content: As far as vibrating the CCD chip, some high end cameras do that but not for that purpose. As I recall they do it to shake the dust from the sensor if any got in there.But that was many years ago, not sure if they still do that.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: July 24, 2015, 12:26:38 pm
content: I'd try two tiny linear actuators (some sort of piezo device maybe?) that can move the CCD by 0.5 of a pixel. You've 4 positions to take samples from so four times the resolution, no fancy maths because you know the exact spacial relation between pixels already*, and obviously only one quarter the frame rate if you need the extra resolution in both directions.*So just a matter of putting each pixels data in the right spot of memory.EDIT: Just thinking about it something like this could be brilliant for people who want very high resolutions but don't need short exposures. Astronomical imaging for example. Especially if you could do increments smaller than 0.5 of a pixel. Need higher resolution? Well have 4 positions for each axis, 8, 16... Bigger pixel sizes on the CCD could even be an advantage in this sort of application.

author: daqq
author_rank: Super Contributor
timestamp: July 28, 2015, 08:22:02 am
content: Thanks for the replies. As with all my ideas, it has been done

author: Halcyon
author_rank: Unknown
timestamp: July 28, 2015, 08:34:19 am
content: Quote from: miguelvp on July 24, 2015, 12:59:55 amNot normally in video cameras but I can confirm my Canon digital SLR does it. It's presents a message on the screen when powering off and it's audible.

author: encryptededdy
author_rank: Frequent Contributor
timestamp: July 28, 2015, 10:27:48 am
content: FLIR actually does this in order to get higher resolution from some of their higher end thermal imagers. They call it "UltraMax":http://www.flir.com/uploadedFiles/Instruments/Products/T-Series/ultramax-technote.pdfQuoteAs an example, the following 1280x960 image came from a 640x480 sensor;