How to create copies of the images. : Say i have different classes of medical x ray images, but they are not equal in number. Some class of images (Image Count) are in 1000's, some are in 100's, some are below 50 and 10. How i can make them equal.? Means i need to create copies of the images. Which is the best method for this. After that i need to do feature extraction. So if i have good number of images in each class i can train well i guess. 

Since x ray images are taken in different angle, mean while i am thinking how can i make some rotation to the existing images when creating duplicate images.