from __future__ import print_function from builtins import range from six.moves import cPickle as pickle import numpy as np import os from imageio import imread import platform def load_pickle(f): version = platform.python_version_tuple() if version[0] == '2': return pickle.load(f) elif version[0] == '3': return pickle.load(f, encoding='latin1') raise ValueError("invalid python version: {}".format(version)) def load_CIFAR_batch(filename): """ load single batch of cifar """ with open(filename, 'rb') as f: datadict = load_pickle(f) X = datadict['data'] Y = datadict['labels'] X = X.reshape(10000, 3, 32, 32).transpose(0,2,3,1).astype("float") Y = np.array(Y) return X, Y def load_CIFAR10(ROOT): """ load all of cifar """ xs = [] ys = [] for b in range(1,6): f = os.path.join(ROOT, 'data_batch_%d' % (b, )) X, Y = load_CIFAR_batch(f) xs.append(X) ys.append(Y) Xtr = np.concatenate(xs) Ytr = np.concatenate(ys) del X, Y Xte, Yte = load_CIFAR_batch(os.path.join(ROOT, 'test_batch')) return Xtr, Ytr, Xte, Yte def get_CIFAR10_data(num_training=49000, num_validation=1000, num_test=1000, subtract_mean=True): """ Load the CIFAR-10 dataset from disk and perform preprocessing to prepare it for classifiers. These are the same steps as we used for the SVM, but condensed to a single function. """ # Load the raw CIFAR-10 data cifar10_dir = 'cs231n/datasets/cifar-10-batches-py' X_train, y_train, X_test, y_test = load_CIFAR10(cifar10_dir) # Subsample the data mask = list(range(num_training, num_training + num_validation)) X_val = X_train[mask] y_val = y_train[mask] mask = list(range(num_training)) X_train = X_train[mask] y_train = y_train[mask] mask = list(range(num_test)) X_test = X_test[mask] y_test = y_test[mask] # Normalize the data: subtract the mean image if subtract_mean: mean_image = np.mean(X_train, axis=0) X_train -= mean_image X_val -= mean_image X_test -= mean_image # Transpose so that channels come first X_train = X_train.transpose(0, 3, 1, 2).copy() X_val = X_val.transpose(0, 3, 1, 2).copy() X_test = X_test.transpose(0, 3, 1, 2).copy() # Package data into a dictionary return { 'X_train': X_train, 'y_train': y_train, 'X_val': X_val, 'y_val': y_val, 'X_test': X_test, 'y_test': y_test, } def load_tiny_imagenet(path, dtype=np.float32, subtract_mean=True): """ Load TinyImageNet. Each of TinyImageNet-100-A, TinyImageNet-100-B, and TinyImageNet-200 have the same directory structure, so this can be used to load any of them. Inputs: - path: String giving path to the directory to load. - dtype: numpy datatype used to load the data. - subtract_mean: Whether to subtract the mean training image. Returns: A dictionary with the following entries: - class_names: A list where class_names[i] is a list of strings giving the WordNet names for class i in the loaded dataset. - X_train: (N_tr, 3, 64, 64) array of training images - y_train: (N_tr,) array of training labels - X_val: (N_val, 3, 64, 64) array of validation images - y_val: (N_val,) array of validation labels - X_test: (N_test, 3, 64, 64) array of testing images. - y_test: (N_test,) array of test labels; if test labels are not available (such as in student code) then y_test will be None. - mean_image: (3, 64, 64) array giving mean training image """ # First load wnids with open(os.path.join(path, 'wnids.txt'), 'r') as f: wnids = [x.strip() for x in f] # Map wnids to integer labels wnid_to_label = {wnid: i for i, wnid in enumerate(wnids)} # Use words.txt to get names for each class with open(os.path.join(path, 'words.txt'), 'r') as f: wnid_to_words = dict(line.split('\t') for line in f) for wnid, words in wnid_to_words.items(): wnid_to_words[wnid] = [w.strip() for w in words.split(',')] class_names = [wnid_to_words[wnid] for wnid in wnids] # Next load training data. X_train = [] y_train = [] for i, wnid in enumerate(wnids): if (i + 1) % 20 == 0: print('loading training data for synset %d / %d' % (i + 1, len(wnids))) # To figure out the filenames we need to open the boxes file boxes_file = os.path.join(path, 'train', wnid, '%s_boxes.txt' % wnid) with open(boxes_file, 'r') as f: filenames = [x.split('\t')[0] for x in f] num_images = len(filenames) X_train_block = np.zeros((num_images, 3, 64, 64), dtype=dtype) y_train_block = wnid_to_label[wnid] * \ np.ones(num_images, dtype=np.int64) for j, img_file in enumerate(filenames): img_file = os.path.join(path, 'train', wnid, 'images', img_file) img = imread(img_file) if img.ndim == 2: ## grayscale file img.shape = (64, 64, 1) X_train_block[j] = img.transpose(2, 0, 1) X_train.append(X_train_block) y_train.append(y_train_block) # We need to concatenate all training data X_train = np.concatenate(X_train, axis=0) y_train = np.concatenate(y_train, axis=0) # Next load validation data with open(os.path.join(path, 'val', 'val_annotations.txt'), 'r') as f: img_files = [] val_wnids = [] for line in f: img_file, wnid = line.split('\t')[:2] img_files.append(img_file) val_wnids.append(wnid) num_val = len(img_files) y_val = np.array([wnid_to_label[wnid] for wnid in val_wnids]) X_val = np.zeros((num_val, 3, 64, 64), dtype=dtype) for i, img_file in enumerate(img_files): img_file = os.path.join(path, 'val', 'images', img_file) img = imread(img_file) if img.ndim == 2: img.shape = (64, 64, 1) X_val[i] = img.transpose(2, 0, 1) # Next load test images # Students won't have test labels, so we need to iterate over files in the # images directory. img_files = os.listdir(os.path.join(path, 'test', 'images')) X_test = np.zeros((len(img_files), 3, 64, 64), dtype=dtype) for i, img_file in enumerate(img_files): img_file = os.path.join(path, 'test', 'images', img_file) img = imread(img_file) if img.ndim == 2: img.shape = (64, 64, 1) X_test[i] = img.transpose(2, 0, 1) y_test = None y_test_file = os.path.join(path, 'test', 'test_annotations.txt') if os.path.isfile(y_test_file): with open(y_test_file, 'r') as f: img_file_to_wnid = {} for line in f: line = line.split('\t') img_file_to_wnid[line[0]] = line[1] y_test = [wnid_to_label[img_file_to_wnid[img_file]] for img_file in img_files] y_test = np.array(y_test) mean_image = X_train.mean(axis=0) if subtract_mean: X_train -= mean_image[None] X_val -= mean_image[None] X_test -= mean_image[None] return { 'class_names': class_names, 'X_train': X_train, 'y_train': y_train, 'X_val': X_val, 'y_val': y_val, 'X_test': X_test, 'y_test': y_test, 'class_names': class_names, 'mean_image': mean_image, } def load_models(models_dir): """ Load saved models from disk. This will attempt to unpickle all files in a directory; any files that give errors on unpickling (such as README.txt) will be skipped. Inputs: - models_dir: String giving the path to a directory containing model files. Each model file is a pickled dictionary with a 'model' field. Returns: A dictionary mapping model file names to models. """ models = {} for model_file in os.listdir(models_dir): with open(os.path.join(models_dir, model_file), 'rb') as f: try: models[model_file] = load_pickle(f)['model'] except pickle.UnpicklingError: continue return models def load_imagenet_val(num=None): """Load a handful of validation images from ImageNet. Inputs: - num: Number of images to load (max of 25) Returns: - X: numpy array with shape [num, 224, 224, 3] - y: numpy array of integer image labels, shape [num] - class_names: dict mapping integer label to class name """ imagenet_fn = 'cs231n/datasets/imagenet_val_25.npz' if not os.path.isfile(imagenet_fn): print('file %s not found' % imagenet_fn) print('Run the following:') print('cd cs231n/datasets') print('bash get_imagenet_val.sh') assert False, 'Need to download imagenet_val_25.npz' f = np.load(imagenet_fn) X = f['X'] y = f['y'] class_names = f['label_map'].item() if num is not None: X = X[:num] y = y[:num] return X, y, class_names