Size of Image used in dlib_face_recognition_resnet_model_v1

What is the input size of image(resolution) that the model dlib_face_recognition_resnet_model_v1.dat.bz2 takes as input?

Also, you mentioned that network was trained from scratch on a dataset which was derived from a number of different datasets. While processing the data to be used for training, what was the resolution that the face images from the different datasets were cropped to and what face detector was used to crop faces from the background?