If an image is 28x28 and MaxPool2d(2) is applied, what is the resulting size?

When applying MaxPool2d with a pool size of 2 on an input image, the operation reduces the spatial dimensions of the image based on the pooling window size. In this particular case, the MaxPool2d(2) applies a 2x2 pooling window over the image, which means that the image is divided into regions of 2x2 pixels.

Each region will be summarized into a single pixel based on the maximum value within that 2x2 area, resulting in a downsampling effect. To calculate the new dimensions after the pooling operation, you divide each dimension of the original image size by the pooling size.

Thus, for an original image size of 28x28:

• The new height = 28 / 2 = 14

• The new width = 28 / 2 = 14

Therefore, the resulting size after applying MaxPool2d(2) to a 28x28 image is 14x14. This shows that the MaxPool operation effectively reduces the size of the original image by half in each dimension due to the pooling factor.