title: How to extract features from an image for training a CNN model
body: <p>I am working on a project to classify waste as plastics and non plastics using only.images to train them.However i still dont know what features does the model take into account while classifyimg them.I am using CNN,however the accuracy of prediction is still not up to the mark.
  The reason why i went to CNN because there is no specific feature to distinguish plastics from others.Is there any other way to approach this problem? 
       For eg If i train the images of cats,my Neural Network learns what is a cat however i do not explicitly give features is the same case valid here too?</p>