Rambus unveils 'Binary Pixel' sensor tech for expanded dynamic range

About time Rambus does something useful.

You cannot trust a company like Rambus. They have a terrible history. They are a patent troll of the highest order. Genuine companies should steer clear of them. They join technology consortiums, with the guise of cooperation and knowledge sharing, then they run off and patent these shared ideas or incorporate it in their patents. Then they mount a battery of lawsuits with companies that would rather give in than expose them. The worst was when Intel partnered with them in the famous RDRAM fiasco, after RDRAM failed they sued almost all the memory manufacturers, after joining JDEC and stealing their ideas and patenting them. This company needs to be put out to pasture. I wont doubt that any technology they are showing off is fluff only to get corporation.

look at this
http://www.design-reuse.com/articles/7411/variable-integration-time-image-sensor-for-wide-dynamic-range.html

I think the bigger news is that Rambus is still in business.

I find many of these wide DR images are lifeless, flat and lacking in dynamics. If blacking out some shadows results in a more dynamic, engaging image, why go HDR?
As for Rambus, things aren't that pretty right now.

http://hothardware.com/News/Third-Most-Important-Rambus-Patent-Invalidated-Company-Share-Price-Craters/

This is a neat idea. Blown highlights are a bigger problem than shadow noise because they are absolutely unrecoverable, while noisy shadows can be smoothed/binned post exposure. Or even during exposure! In such a hypothetic sensor, highlight pixels could reset multiple times during exposure to improve headroom, while at the same time shadow pixels could be binned to improve shadow S/N ratio (at the expense of resolution) all at once.

contrast+ :)))

Rambus is not so much a technology company, but rather a patent lawsuit mill.

Best to walk away from anything they develop, it's likely just something their attorneys will use to sue people.

Going to the logical end, a single pixel can work in a binary mode (detecting light or darkness) similar to dithered images of printers. When they create pixels with 50nm pitch then it can be possible to have image quality close to today's sensors.

But pretty soon, they will hit the law of diminishing returns, the quantum noise is determined by the total light collected by the surface of the sensor. For example, even ideal (noiseless) micro 4/3 sensor will not be able to achieve the performance of today's (not ideal) FF sensor.

I prefer left picture (conventional) to the right picture (hdr).

I should mention here that I have been working with Rambus for a few years and they fund our Quanta Image Sensor R&D at Dartmouth, along with other projects elsewhere. I believe their strategy is to invest in R&D that yields fundamental IP in advanced areas. It is an interesting business model and one that actually supports innovation and technology development even if they are ultimately a non-practicing entity.

Reminds me somewhat of a forum post I made a few years ago...

See http://forums.dpreview.com/forums/post/18895569

Regards, Nigel

I made some comments on this in the news forum yesterday including a reference to technical work they published. Bottom line, I am a big fan of binary pixels and oversampling (spatially and temporally) and believe this is where things are headed even for large sensor cameras.

I see there is some wrong information being circulated in this comments section so readers, beware!

Sadly the company is RAMBUS so it means this technology will be very expensive and likely replaced be something better and cheaper 3 months after release but RAMBUS will spend the next 5 years suing everyone to prevent the adaptation of the cheaper technology.

Great, more bland pics.

Good to see some actual innovation in the sensor arena. Far too much of digital photography hitherto has been in replacing film, but the opportunities in digital extend well beyond that. This is a great idea and I see no reason why they couldn't reset the pixels more than once -- just keep track of the number of resets and add enough bits to count the resets. Two bits gives you four resets, that should do it.

Watch out camera industry, lawsuits are coming!

I'm not sure this is so fabulous for most "small sensor" cameras, except that the bulk of the sensors produced are of that type. I generally don't have a driving need for expanding the bright side of the dynamic range in 1/2.3 (or smaller) cameras - what I really need is more sensitivity in dark scenes.

While you could claim that this allows getting more light to the sensor without blowing highlights...yes - sort of. Most exposures are limited by absolute duration (shake/subject movement) and not the fear of clipping on highlights.

More like US Patent Troll.

If this can hold the highlights without flattening everything (HDR Smokevision effect) it would be great and a shame to waste on cellphones.

Is this something like floating point?

This is essentially the same idea as multiple exposures using electronic shutter. For example, you take 4 normal exposures and merge them into a single image, you get 2 times better SNR (and dynamic range) and effectively pushing ISO 4 times lower. You can do it today with cameras like Sony NEX, except the shutter is not electronic, it's mechanical, so there is problem with moving subjects.
On the subject of the dynamic range. The displays and prints have a lot more limited dynamic range than modern sensors. In order to display higher dynamic range you need to compress it, the more you compress, the less natural image looks. Until displays with much better dynamic range are built, increasing dynamic range of the sensor has little advantages.

Essentially a counter and reset for the pixel bucket.

Since they call it binary, I will assume that for now, the counter is essentially just one bit.

You can probably do this with just a few transistors, that will trip automatically when the pixel bucket hits full. It sets one bit cleans the bucket, and start collecting again.

One of those obvious in hindsight ideas that should really work out well.

I am just sad that patent troll Rambus thought of it first.

I may be wrong, but I think the idea behind that can be explained as follows :
A photosite can be seen as a bucket that is being filled up with electrons when exposed to light. Overexposure occurs when the bucket overflows.
But filling the bucket is not instantaneous. It looks to me like Rambus brings up a new technology that allows to monitor the bucket level. Then it is possible to empty ("reset") the bucket (and memorize it was filled up once, and maybe more than once) and restart filling it until the shutter closes.
The final electrical level corresponding to the total amount of light received by the photosite is then the sum of as many as necessary full buckets and the last partially filled bucket.
Highly sensitive photosites are quickly saturated. But with this new technology, saturation is no longer a problem.
So the advantages are both in lowlight capability and dynamic range.

Sounds a great idea. Only problem I can see is if the time to reset the pixel is significant compared to the exposure time. In that case the pixel wouldn't gain any extra charge during the reset and this would leave a plateau in the signal before increasing again, giving a lower value than it really should be.
Nothing says it needs to stop at one reset either. If this works consistently it could be a really impressive next step for sensors.

Its quite interesting, but given Rambus history of "patents" (they are great patent trolls) I wouldnt put much faith into it.

Ofc in theory it should work..