You may have heard companies like Google and Huawei touting the term, Pixel Binning. While the technology isn’t new, many companies have put it to work recently, particularly to improve smartphone cameras.
Do we need this? To begin with, Pixel Binning does help tackle a specific problem that these cameras face against larger (digital single-lens reflex) DSLR cameras—the sensor size.
Smartphones do not have as much space as DSLR cameras to hold large sensors.
As a result, the camera sensors inside phones have never been very big, which in turn reduces the amount of light that they capture. This is why smartphone cameras have always been weaker in shooting low-light photos, than in other conditions.
What is a pixel? In theory, pixels on a camera sensor are photosensitive diodes that are selectively sensitive to red, green or blue frequencies, hence breaking down incident light to capture more colour data. Typically, pixels are arranged in grids, where image processors take data from and combine to create photographs that you see. The quality of photographs often depend on how large a pixel is, and how much data is captured by them, hence creating the best balance between brightness and colours.
How does Pixel Binning help? In Pixel Binning, multiple adjacent pixels are combined into one. Pixel Binning on current smartphones is done by combining smaller pixels into 2x2 grids, hence creating overall “effective pixel" size that is larger than the standard pixels. Since four pixels are combined or “binned" together, the effective resolution is reduced to a quarter of the total sensor resolution —48MP, in case of the Sony IMX586 and the Samsung ISOCELL GM1.
So, what you get are 12MP photographs, hence maintaining the ideal, industry standard resolution of photos in terms of file size and quality. These photographs, after being shot with 48MP sensors, retain better colour details, textures and far superior low-light photography quality. This is because with Pixel Binning, the overall sensitivity to light of an image sensor is improved, which makes it “see" more in darkness. It is this imaging technology that powers an upcoming Xiaomi Redmi Note 7 and the recently launched Honor View 20, hence creating photographs that can almost emulate the photograph quality of dedicated cameras.