Solution: Pooling Mechanics

Solution

The answer is 2x2x5. Here's how it's calculated using the formula:

(4 - 2)/2 + 1 = 2
(4 - 2)/2 + 1 = 2

The depth stays the same.

Here's the corresponding code:

input = tf.placeholder(tf.float32, (None, 4, 4, 5))
filter_shape = [1, 2, 2, 1]
strides = [1, 2, 2, 1]
padding = 'VALID'
pool = tf.nn.max_pool(input, filter_shape, strides, padding)

The output shape of pool will be [1, 2, 2, 5], even if padding is changed to 'SAME'.