what people do is pre train a large convolutional neural network on some data set of large images and you know image net gets a special shout-out here it's extremely popular for for pre training so much so that there are sort of entire papers saying why image net is good for transfer learning but besides that there are a couple of other data sets so ms cocoa is a very popular big computer vision benchmark for object detection that sometimes used for pre training and companies also tend to have their own internal data sets which they