Prepare to see another giant leap in smartphone picture-taking quality this year.
Sony announced today three new back-illuminated stacked CMOS image sensors optimized for bright and low-light conditions. The new compact sensors are faster, consume less power than previous versions, and will be available in 8- to 13- megapixel flavors. Most notably, the sensors feature new "RGBW Coding" and "High Dynamic Range (HDR) Movie" abilities baked directly onto the hardware. The iPhone 4S features a Sony 8-megapixel sensor, and it's possible that this may be a preview of the camera sensor inside the iPhone 5.
You might recognize the RGB acronym, as it stands for red-green-blue; the new sensor adds white pixels to the mix that pumps up the sensor's light sensitivity. It is possible that a future smartphone with this sensor will have little problem shooting pictures in dark rooms (or at night), as evidenced in the example picture above. Another benefit to the RGBW coding is that no changes to signal processing are required to support this updated technology, making it easy to implement. Surprisingly, Kodak has been shopping around something like this technology since at least 2007.
The addition of HDR movie mode could be the most compelling announcement of all. As demonstrated in the video, a normal movie shot on a smartphone often suffers from a washed out effect against bright light, or excessive shadowing in darker areas. In real time, the sensor adjusts accordingly by "setting two different exposure conditions within a single screen shooting and conducts the appropriate signal processing for the captured information under each optimal exposure condition."
It seems that the HDR function works well, and from my observations, does not dilute or emphasize color as a side effect.
A side note in the press release also describes how one of these CMOS sensors has built-in signal processing (in the past, this was embedded separately). Sony will begin shipping these sensors to manufacturers starting in March, while the HDR/RGBW version ships in June.