Daniel Voigt Godoy - Deep Learning with PyTorch Step-by-Step A Beginner’s Guide-leanpub

Output
----------------------------------------------------------------
ValueError
Traceback (most recent call last)
<ipython-input-9-fa0fcce9e228> in <module>
----> 1 last_horizontal_region * identity
ValueError: operands could not be broadcast together with shapes
(1,1,3,2) (1,1,3,3)
Shape
Next, we go back to the left side and move down one step. If we repeat the
operation, covering all valid regions, we’ll end up with a resulting image that is
smaller (on the right).
Figure 5.8 - Fully convolved
"How much smaller is it going to be?"
It depends on the size of the filter.
The larger the filter, the smaller the resulting image.
Since applying a filter always produces a single value, the reduction is equal to the
filter size minus one. If the input image has (h i , w i ) shape (we’re disregarding the
channel dimension for now), and the filter has (h f , w f ) shape, the shape of the
resulting image is given by:
Equation 5.1 - Shape after a convolution
Convolutions | 351