[pytoch] learning notes (I) create your own data set

Custom datasets
If you want to use your own data set , Must be realized 3 A way : __init__(),__len__() And __getitem__().
___init__():
Call once when initializing the dataset , We initialize some data in the initialization method , for example , Initialize image path , Initialization of annotation file and data preprocessing .
__len__():
Returns the amount of data in the dataset
__getitem__():
__getitem__() According to the given idx, Load and then return a sample . be based on idx, Find the picture and convert it to tensor. Traverse label, Call custom transform Function to complete image preprocessing . Eventually return tensor Materialized picture and corresponding tag tuple .