Figure 1
From: Analysis and processing of pixel binning for color image sensor

Commonly used binning schemes. Binning refers to the concept of combining the electrical charges of neighboring pixels together to form a superpixel. (a–b) The numbers over the high resolution Bayer pattern indicate which pixels are combined together. (c) The resultant superpixel Bayer pattern, where the numbers indicate the relative locations of the combined pixels (for [7] and [5]).