# receptive field

\[ r_0 = \sum_{l=1}^{L} \left( (k_l-1) \prod_{i=1}^{l-1} s_i \right) + w \]

where

- \(r_0\) is the number of pixels from the image than influence one pixel of the final output layer \(L\)
- \(k_l\) is the kernel length at layer \(l\)
- \(s_i\) is the stride length

NOTE: \(L\) is the last layer, \(l=0\) is the input image