(2+1)D Convolution
(2+1)D Convolution
A **(2+1)D Convolution** is a type of [convolution](https://paperswithcode.com/method/convolution) used for action recognition convolutional neural networks, with a spatiotemporal volume. As opposed to applying a [3D Convolution](https://paperswithcode.com/method/3d-convolution) over the entire volume, which can be computationally expensive and lead to overfitting, a (2+1)D convolution splits computation into two convolutions: a spatial 2D convolution followed by a temporal 1D convolution.
A Closer Look at Spatiotemporal Convolutions for Action Recognition
https://paperswithcode.com/paper/a-closer-look-at-spatiotemporal-convolutions
A Closer Look at Spatiotemporal Convolutions for Action Recognition