CNN – Image Resizing VS Padding (keeping aspect ratio or not?)

According to Jeremy Howard, padding a big piece of the image (64×160 pixels) will have the following effect: The CNN will have to learn that the black part of the image is not relevant and does not help distinguishing between the classes (in a classification setting), as there is no correlation between the pixels in … Read more

2-D convolution as a matrix-matrix multiplication [closed]

Yes, it is possible and you should also use a doubly block circulant matrix (which is a special case of Toeplitz matrix). I will give you an example with a small size of kernel and the input, but it is possible to construct Toeplitz matrix for any kernel. So you have a 2d input x … Read more

Dimension of shape in conv1D

td; lr you need to reshape you data to have a spatial dimension for Conv1d to make sense: X = np.expand_dims(X, axis=2) # reshape (569, 30) to (569, 30, 1) # now input can be set as model.add(Conv1D(2,2,activation=’relu’,input_shape=(30, 1)) Essentially reshaping a dataset that looks like this: features .8, .1, .3 .2, .4, .6 .7, … Read more

What does the parameter retain_graph mean in the Variable’s backward() method?

@cleros is pretty on the point about the use of retain_graph=True. In essence, it will retain any necessary information to calculate a certain variable, so that we can do backward pass on it. An illustrative example Suppose that we have a computation graph shown above. The variable d and e is the output, and a … Read more

How to calculate the number of parameters for convolutional neural network?

Let’s first look at how the number of learnable parameters is calculated for each individual type of layer you have, and then calculate the number of parameters in your example. Input layer: All the input layer does is read the input image, so there are no parameters you could learn here. Convolutional layers: Consider a … Read more

Instance Normalisation vs Batch normalisation

Definition Let’s begin with the strict definition of both: Batch normalization Instance normalization As you can notice, they are doing the same thing, except for the number of input tensors that are normalized jointly. Batch version normalizes all images across the batch and spatial locations (in the CNN case, in the ordinary case it’s different); … Read more