How to oversample image dataset using Python?
Thanks for the clarification.  In general, you don't oversample with Python.  Rather, you pre-process your data base, duplicating the short-handed classes.  In the case you cite, you might duplicate everything in class B, and make 5 copies of everything in class C.  This gives you a new balance of 1000:600:500, likely more palatable to your training routines.  Instead of the original 1400 images, you now shuffle 2100.
Does that solve your problem?
I am working on a multiclass classification problem with an unbalanced dataset of images(different class). I tried imblearn library, but it is not working on the image dataset.
I have a dataset of images belonging to 3 class namely A,B,C. A has 1000 data, B has 300 and C has 100. I want to oversample class B and C, so that I can avoid data imbalance. Please let me know how to oversample the image dataset using python.