Hi

what does this line of code do ?

return data.trn_ds.denorm(x)[2]

This is the doc for the function:

```
Reverse the normalization done to a batch of images.
Arguments: arr: of shape/size (N,3,sz,sz)
```

So this undoes the image normalization on `x`

.

The normalization is subtracting mean of the data and dividing by standard deviation. (This will be mean and stddev of ImageNet, when using a pretrained model!). Therefore this will take your images, multiply them by that same stddev and add the mean back to them.

The `[2]`

just indexes the resulting tensor in the batch dimension, meaning it returns the third image of this batch. I would not see why this is a sensible thing to do tho, in the function you’re showing.

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very tanks to you!