Nokia 808 PureView technique explained

Yesterday Nokia surprised the Mobile World Congress with an astonishing new camera phone: the 808 Pureview. It has a whopping 41MP sensor behind the Carl Zeiss lense, and turn the pictures you make into 3MP, 5MP of 8MP – your choice. But how does this work?

The technology used is called “picture oversampling”: combining the information of several pixels into one “superpixel”. Simply put, it appears to be a compression technique we all know from for example MP3 and AAC+. Let’s try to explain as simple as possible!

The complete size of the sensor is 7728x5368 pixels. In 16:9 format it uses the long side of the sensor (7728 pixels),in 4:3 format it’s maximum height (5368 pixels). In the first case it will use 34MP, in the second case 38MP from the total amount.

The picture below shows it clearly:

After you have made the picture, the 808 PureView will render all information on the sensor to the format you’ve chosen: 3MP, 5MP or 8MP. For instance, if you made a picture in 4:3 and save it in a 5MP format, it will use the information from about 7 pixels into each pixel it needs to create the final result.

To make it even more tangible what this all means, here you find a video Nokia pulished with Juha Alakarhu, the Head of Imaging Technology.

If you want to read all technical details, you can have a long look at Nokia’s Whitepaper

On the right hand you see a close up picture from the actual sensor, taken at the Nokia stand during the Mobile World Congress in Barcelona.

When zooming in on  a detail, you actually zoom in on the relevant part of the sensor. For instance, if you make a 5MP picture, the resolution (in 16:9) will be 3072x1728 pixels. When you don’t zoom in, the phone will render all information it has from 34MP into that amount.

But if you do zoom in, 3072x1728 is your limit: you won’t be able to zoom in any further. There won’t be any oversampling any more, you will get one pixel for each pixel. What you see is what you get. But there is no digital “enlargement” either.

The same goes for making video’s: you can zoom in up to 4 times when you record in full HD (1080p), and 6 times when you record in HD (720p) – without losing any picture quality!

Rich recording
Talking about videos: a new very exciting technique premiered in the 808 PureView is “Rich Recording”, offering a truly astonishing sound quality You would have to hear it for yourself, and luckily, you can: check this promotional video out in which Nokia wants to prove the sound quality.