Friday, January 25, 2013

Sony Explains HDR Video Mode in its Stacked Sensor

Sony Mobile published a nice explanation of the "HDR Video" mode in its stacked Exmor RS sensors inside the flagship Xperia Z smartphone:

How HDR video recording works
To achieve true HDR video recording, the advanced Exmor RS camera sensor in Xperia Z changes the exposure every two lines of pixels. This creates a spatially varying exposure (SVE) array image, which is then used to make an image that is perfectly exposed in both dark and light areas.

To simplify the concept, for each frame the camera shoots one picture with two different exposure levels at the same time, one light and one dark. Then, an intelligent software algorithm is used to combine (synthesize) the two shots into one picture, pixel by pixel. This allows you to see the details of both the dark and the bright parts of the picture.

HDR for still images
With HDR for still images, the camera quickly captures the image twice with different exposure levels and stitches the two shots together to create one optimised photo. This way, HDR lets you capture clear photos even against strong backlight. HDR is automatically activated when Superior Auto detects scenes with strong backlight.


  1. RGBW! Nice! Much more interesting than this HDR modes, in fact...

    Now: why would they put the two green pixels together? Maybe it is to avoid aliasing, but my guess would be that swapping the second-row green for the first-row red would be a better idea.
    Or, even better, you could replace one of those greens by black (deep ND) and create a single-exposure HDR image that is a nightmare to debayer :)

  2. RGBW?

    I though Sony pulled RGBW from Exmoor RS in August 2012?

    Quote: Sony Corporation (“Sony”) announced specification changes to Stacked CMOS Image Sensors, “IMX135” and “IMX134” and Imaging Modules, “IU135F3-Z” and “IU134F9-Z”*, which are scheduled for phased launch starting January 2013.* Sony will incorporate the existing RGB method into these models, in place of the originally planned ‘RGBW coding’ function, as it was found not to meet certain conditions of Sony's image quality standards.

    I suspect the graphic artists didn't get the message? :-)

  3. So thats how they did it.... not impressed

  4. RGBW didnt work as expected, the image above is from RGBW with video HDR funtion.
    the CMOS RS sensors do not have white and are standard bayer pattern

  5. green pixels are next to each other, because the green color carries the most information about the details and sharpness. And not only are these pixels next to each otherbut there are more than others ... for the same reason. And it is well known thing in the case of digital cameras


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