[week 1 Programming Assignment #2] ZeroPadding2D with padding 3, input shape of 64 x 64 x 3

Course Q&A Deep Learning Specialization Convolutional Neural Networks
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Hi,

I have a doubt regarding the last assignment of Week 1.

When defining the model, we are required to specify an input shape of 64 x 64 x 3.

However, it is unclear to me how to do this. Obviously, I have looked at the documentation (tf.keras.layers.ZeroPadding2D  |  TensorFlow Core v2.4.1) and Googled quite a bit, but would appreciate some pointer or some understanding of what is going on because I have been stuck here for the whole afternoon.

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Solved. For future reference: it goes as an argument inside the tfl.ZeroPadding2D function

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Hi vaccam1,

input_shape can be used as a parameter in ZeroPadding2D. Unfortunately this is not mentioned in the documentation.

I hope this brightens your afternoon!

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Hi vaccam1,

Good to read you resolved the issue. Could you please remove your explicit piece of code?

Thanks and good luck with the rest of the course!

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Done, thanks and take care

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Hi @reinoudbosch, It will help me to sleep now…!! :heart_eyes:

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@nomi This info will also help to grab some pakoras that have become cold as I was stuck here for a while now. Thanks @reinoudbosch

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But how can you explain this usage of a class
y = tf.keras.layers.ZeroPadding2D(padding=1)(x)

taken from tensorflow documentation

I mean : ZeroPadding2D is a class, so with any class (say ‘y’), we can use : y(some args) to instantiate an object of the class type.
But what does this → y(some args)(something) mean?

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@ashish_learns Lol :joy:

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@ashish_learns you will understand this while doing assignment of functional model. Actually it is like pipeline, in y = tf.keras.layers.ZeroPadding2D(padding=1)(x) assume x as a input that come from previous layer and in next layer, let suppose z = tf.keras.layers.MaxPool2D(pool_size=(2, 2), strides=None, padding='valid')(y) will be placed on x.

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Okay.
I have been using Python for more than 4 years and have never come across this type of programming construct, where apart from the usual () for instantiating object of a class, we also have an extra () just after this —> tf.keras.layers.ZeroPadding2D(padding=1)(x)

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@ashish_learns yeah me too. I have also seen this format in only tensorflow.

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bhai, if you get something about this then don’t forget to share here

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@ashish_learns sure i will.

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I would suggest this info be added to the assignment as a hint. There is no way we could find out that input_shape is a parameter, other than guessing, or hoping to find it here. I spent a lot of time trying to figure out how to make it work, only to find out there is some hidden parameter to use that’s not in the docs.

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Thanks a lot with this hint. :wink:

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You saved my day! I also got stuck (for whole morning) by just reading the example in the doc. I really think they should add a clearer example.