Gender classifier with Tensorflow and OpenCV

Now that we can easily download images, we write a new method which downloads and renames the images for us. After we have downloaded the images, we filter out all images with the wrong file extention or too low quality (size too small). Then, we rename the images to follow the naming pattern img_X.jpg. Now that we have some images for the classification, we need to make sure the Neural Network is trained on exactly the same data that he shall later recognize. That is: The face of human, and only the face. The images we downloaded mostly consist of the head, hair, and most of the times even clothing of humans -- but we do not want that.