[Week 3 Quiz] Logic on Filter Impact on Image Size

Hi all -

The below questions came up on the Quiz in week 3 - can you help me understand the logic here? Not sure I’m fully understanding the rationale.

[True or False] if you pass a 28X28 image through a 3X3 filter the output will be 26X26 [TRUE]

[True or False] After Max Pooling a 26X26 image with a 2X2 filter, the output will be 56X56 [False]

Thank you!


Hi R.E,

If you pass a 28x28 image through 3x3 filter you’ll get 26x26, since the edge pixels on all 4 sides will get clipped. Here is a good visual description of the process with different filter sizes and strides.
Note: here they are referring to the convolution operation here in the question and not max-pooling.

In max-pooling on the other hand, if you pass a 26x26 image through a 2x2 max-pooling filter, you’ll get a 13x13 output, refer this link for more details.

Hope this clarifies.

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