The 16 MP ISOCELL Slim 3P9 camera by Samsung is a solution for mid-range devices and, thanks to the Tetracell technology, its 1 μm sensor can act as a 2 μm unit by merging four neighboring pixels. This way, the next-gen front-facing cameras can take better pictures in low light scenarios.
https://www.notebookcheck.net/Samsung-intros-the-16-MP-ISOCELL-Slim-3P9-image-sensor.301818.0.html