Which activation function can be used in the output layer for face recognition?

In this example, which activation function can be used to predict the probability of being person XYZ?

HI @Jinyan_Liu

In this example there are one neuron so that the probability of being person XYZ could be done using sigmoid activation function, if there are multiclassification(more than 2 labels) you can use softmax activation function

so if i have 2 names to predict, i should be using sigmoid as it gives a binary probability, but when i have , say 10 names to predict than i shall go for other activation functions like softmax. Right?

Right.

Ah I think I misunderstood the example. So before the prediction happens, the model has been trained on multiple of her images and others, with y_train to be 0 or 1.(speaking of this example)

So what I really want to ask is different : just by giving an image, to predict a name, and the model has been trained with a billion of different people’s images and names(so y_train has a billion of names). What would be the activation function to predict the probability of being XYZ? Would softmax work?

If it is a multiclass problem (having the information that you have a class XYZ) then softmax would give you this probability. If the goal is a similarity between two faces, then a linear activation.

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Hello @Jinyan_Liu ,

Choice of activation function for this task depends on the specific requirements of the application.

Softmax function is a good choice for this task because it is able to handle a large number of classes.
So Softmax is preferable.

With regards,
Nilosree Sengupta

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Thank you so much @Nydia and @nilosreesengupta ! In the course, the multi classes examples don’t have a large number of classes, that’s why I was wondering. Now I understand, thank you!

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Hello @Jinyan_Liu ,

You’re welcome!!
Happy learning.

With regards,
Nilosree Sengupta