Global Average Pooling

Definition

Global average pooling (GAP) is a technique reducing the spatial dimension of feature maps to a single value per channel. $\mathrm{GAP}:(h\times w\times c)\to (1\times 1\times c),GAP(x)=\frac{1}{h\times w}\sum _{i=1}^h\sum _{j=1}^w{x}_{ij}$ where $x_{ij}$ is the value at position $(i,j)$ in the feature map.