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Full random access to CMOS image sensor
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Last seen: 1 year 22 weeks ago
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Joined: 2013-02-16
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So in theory it looks like a CMOS sensor allows "random access" to it' s pixels -- which is exactly what I want (I want to pull my images from the sensor using non-standard scanning patterns, etc).  In reality, it looks like many cmos sensors from aptina, etc providethe video in a few standard scan patterns (progressive, interlaced) -- presumably as a "convenience"
 
++Does anyone know of a CMOS sensor that allows for completely arbitrary, full user programable scan pattern?
++  Some CMOS sensors allow specifying a region on interest or window -- can the windows be changed at fairly high speed (faster than frame rate) -- separately, I have seen a sensor from fairchild semiconductor that allows the frame rate to be increased signficantly as the window size decreases (allowing for essentially constant bandwidth).  I get the sense that this sensor is quite expensive.  I noticed from aptina allows windows of interest but the frame rate stays the same (I think)/  In theory a user controllable window would be ok for my needs assuming it could be as small as 5x5 and jump around arbitrarily at high speeds.  Does anyone know of such a sensor?
 
thanks! 
 
 

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Last seen: 7 weeks 14 hours ago
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Mostly, reading out single pixels is a process limited by access speed.  In the Fovoen sensor we sell, you can set both the Row and column start addresses and then read out just one pixel.  However, to go to the next one, you have to reload the registers.  This takes tens of microseconds.  Most sensors allow at least the row start address to be selected so you can select a row and then read out until you get to the pixel you want.  This may be faster than the Foveon method depending on the clock rate and the number of sensor taps.  Of course, complet redout regiater structures can ruin this whole idea. 
One advantage of CMOS is that most sensor allow non-destructive read so you can iintegrate just once, then select a few pixels.  Unless the sensor has a global shutter, though, the integration time will be longer for the later pixels. 

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Last seen: 51 weeks 6 days ago
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Not 100% sure if it meets your needs, but I would take a look at XIMEA (http://www.ximea.com).  They have a lot of CMOS based sensors, and I know that you can switch things like ROI, etc. (see API: http://www.ximea.com/support/wiki/apis/XiAPI_Manual).  They also have a lot of OEM based sensors, so if you can't find what you are looking for on their site you may just want to contact them directly.