#!/usr/bin/env python # Software License Agreement (BSD License) # # Copyright (c) 2012, Philipp Wagner . # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # # * Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # * Redistributions in binary form must reproduce the above # copyright notice, this list of conditions and the following # disclaimer in the documentation and/or other materials provided # with the distribution. # * Neither the name of the author nor the names of its # contributors may be used to endorse or promote products derived # from this software without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE # POSSIBILITY OF SUCH DAMAGE. import os import sys import cv2 import numpy as np def normalize(X, low, high, dtype=None): """Normalizes a given array in X to a value between low and high.""" X = np.asarray(X) minX, maxX = np.min(X), np.max(X) # normalize to [0...1]. X = X - float(minX) X = X / float((maxX - minX)) # scale to [low...high]. X = X * (high-low) X = X + low if dtype is None: return np.asarray(X) return np.asarray(X, dtype=dtype) def read_images(path, sz=None): """Reads the images in a given folder, resizes images on the fly if size is given. Args: path: Path to a folder with subfolders representing the subjects (persons). sz: A tuple with the size Resizes Returns: A list [X,y] X: The images, which is a Python list of numpy arrays. y: The corresponding labels (the unique number of the subject, person) in a Python list. """ c = 0 X,y = [], [] for dirname, dirnames, filenames in os.walk(path): for subdirname in dirnames: subject_path = os.path.join(dirname, subdirname) for filename in os.listdir(subject_path): try: im = cv2.imread(os.path.join(subject_path, filename), cv2.IMREAD_GRAYSCALE) # resize to given size (if given) if (sz is not None): im = cv2.resize(im, sz) X.append(np.asarray(im, dtype=np.uint8)) y.append(c) except IOError, (errno, strerror): print "I/O error({0}): {1}".format(errno, strerror) except: print "Unexpected error:", sys.exc_info()[0] raise c = c+1 return [X,y] if __name__ == "__main__": # This is where we write the images, if an output_dir is given # in command line: out_dir = None # You'll need at least a path to your image data, please see # the tutorial coming with this source code on how to prepare # your image data: if len(sys.argv) < 2: print "USAGE: facerec_demo.py []" sys.exit() # Now read in the image data. This must be a valid path! [X,y] = read_images(sys.argv[1]) # Convert labels to 32bit integers. This is a workaround for 64bit machines, # because the labels will truncated else. This will be fixed in code as # soon as possible, so Python users don't need to know about this. # Thanks to Leo Dirac for reporting: y = np.asarray(y, dtype=np.int32) # If a out_dir is given, set it: if len(sys.argv) == 3: out_dir = sys.argv[2] # Create the Eigenfaces model. We are going to use the default # parameters for this simple example, please read the documentation # for thresholding: model = cv2.createEigenFaceRecognizer() # Read # Learn the model. Remember our function returns Python lists, # so we use np.asarray to turn them into NumPy lists to make # the OpenCV wrapper happy: model.train(np.asarray(X), np.asarray(y)) # We now get a prediction from the model! In reality you # should always use unseen images for testing your model. # But so many people were confused, when I sliced an image # off in the C++ version, so I am just using an image we # have trained with. # # model.predict is going to return the predicted label and # the associated confidence: [p_label, p_confidence] = model.predict(np.asarray(X[0])) # Print it: print "Predicted label = %d (confidence=%.2f)" % (p_label, p_confidence) # Cool! Finally we'll plot the Eigenfaces, because that's # what most people read in the papers are keen to see. # # Just like in C++ you have access to all model internal # data, because the cv::FaceRecognizer is a cv::Algorithm. # # You can see the available parameters with getParams(): print model.getParams() # Now let's get some data: mean = model.getMat("mean") eigenvectors = model.getMat("eigenvectors") # We'll save the mean, by first normalizing it: mean_norm = normalize(mean, 0, 255, dtype=np.uint8) mean_resized = mean_norm.reshape(X[0].shape) if out_dir is None: cv2.imshow("mean", mean_resized) else: cv2.imwrite("%s/mean.png" % (out_dir), mean_resized) # Turn the first (at most) 16 eigenvectors into grayscale # images. You could also use cv::normalize here, but sticking # to NumPy is much easier for now. # Note: eigenvectors are stored by column: for i in xrange(min(len(X), 16)): eigenvector_i = eigenvectors[:,i].reshape(X[0].shape) eigenvector_i_norm = normalize(eigenvector_i, 0, 255, dtype=np.uint8) # Show or save the images: if out_dir is None: cv2.imshow("%s/eigenface_%d" % (out_dir,i), eigenvector_i_norm) else: cv2.imwrite("%s/eigenface_%d.png" % (out_dir,i), eigenvector_i_norm) # Show the images: if out_dir is None: cv2.waitKey(0)