--- a +++ b/gait_nn.py @@ -0,0 +1,287 @@ +import settings +import os + +import tensorflow as tf +import tensorflow.contrib.layers as layers +import numpy as np + +from abc import abstractmethod + +slim = tf.contrib.slim + +SUMMARY_PATH = settings.LOGDIR_GAIT_PATH +KEY_SUMMARIES = tf.GraphKeys.SUMMARIES + +SEED = 0 +np.random.seed(SEED) + + +class GaitNN(object): + def __init__(self, name, input_tensor, features, num_of_persons, reuse = False, is_train = True, + count_of_training_examples = 1000): + self.input_tensor = input_tensor + self.is_train = is_train + self.name = name + + self.FEATURES = features + + net = self.pre_process(input_tensor) + net, gait_signature, state = self.get_network(net, is_train, reuse) + + self.network = net + self.gait_signature = gait_signature + self.state = state + + if is_train: + # Initialize placeholders + self.desired_person = tf.placeholder( + dtype = tf.int32, + shape = [], + name = 'desired_person') + + self.desired_person_one_hot = tf.one_hot(self.desired_person, num_of_persons, dtype = tf.float32) + self.loss = self._sigm_ce_loss() + + self.global_step = tf.Variable(0, name = 'global_step', trainable = False) + + self.learning_rate = tf.placeholder( + dtype = tf.float32, + shape = [], + name = 'learning_rate') + + def _learning_rate_decay_fn(learning_rate, global_step): + return tf.train.exponential_decay( + learning_rate, + global_step, + decay_steps = count_of_training_examples * 2, + decay_rate = 0.96, + staircase = True) + + self.optimize = layers.optimize_loss(loss = self.loss, + global_step = self.global_step, + learning_rate = self.learning_rate, + summaries = layers.optimizers.OPTIMIZER_SUMMARIES, + optimizer = tf.train.RMSPropOptimizer, + learning_rate_decay_fn = _learning_rate_decay_fn, + clip_gradients = 0.1, + ) + + self.sess = tf.Session() + self.sess.run(tf.global_variables_initializer()) + + # Initialize summaries + if name is not None: + if is_train: + logdir = os.path.join(SUMMARY_PATH, self.name, 'train') + self.summary_writer = tf.train.SummaryWriter(logdir) + + self.ALL_SUMMARIES = tf.merge_all_summaries(KEY_SUMMARIES) + else: + self.summary_writer_d = {} + + for t in ['avg', 'n', 'b', 's']: + logdir = os.path.join(SUMMARY_PATH, self.name, 'val_%s' % t) + self.summary_writer_d[t] = tf.train.SummaryWriter(logdir) + + tf.set_random_seed(SEED) + + @staticmethod + def pre_process(inp): + return inp / 100.0 + + @staticmethod + def get_arg_scope(is_training): + weight_decay_l2 = 0.1 + batch_norm_decay = 0.999 + batch_norm_epsilon = 0.0001 + + with slim.arg_scope([slim.conv2d, slim.fully_connected, layers.separable_convolution2d], + weights_regularizer = slim.l2_regularizer(weight_decay_l2), + biases_regularizer = slim.l2_regularizer(weight_decay_l2), + weights_initializer = layers.variance_scaling_initializer(), + ): + batch_norm_params = { + 'decay': batch_norm_decay, + 'epsilon': batch_norm_epsilon + } + with slim.arg_scope([slim.batch_norm, slim.dropout], + is_training = is_training): + with slim.arg_scope([slim.batch_norm], + **batch_norm_params): + with slim.arg_scope([slim.conv2d, layers.separable_convolution2d, layers.fully_connected], + activation_fn = tf.nn.elu, + normalizer_fn = slim.batch_norm, + normalizer_params = batch_norm_params) as scope: + return scope + + def _sigm_ce_loss(self): + ce = tf.nn.softmax_cross_entropy_with_logits(logits = self.network, labels = self.desired_person_one_hot) + loss = tf.reduce_mean(ce) + + return loss + + def train(self, input_tensor, desired_person, learning_rate): + if not self.is_train: + raise Exception('Network is not in training mode!') + + self.sess.run(self.optimize, feed_dict = { + self.input_tensor: input_tensor, + self.desired_person: desired_person, + self.learning_rate: learning_rate + }) + + def feed_forward(self, x): + out, states = self.sess.run([self.gait_signature, self.state], feed_dict = {self.input_tensor: x}) + + return out, states + + def write_test_summary(self, err, epoch, t = 'all'): + loss_summ = tf.Summary() + loss_summ.value.add( + tag = 'Classification in percent', + simple_value = float(err)) + + self.summary_writer_d[t].add_summary(loss_summ, epoch) + self.summary_writer_d[t].flush() + + def write_summary(self, inputs, desired_person, learning_rate, write_frequency = 50): + step = tf.train.global_step(self.sess, self.global_step) + + if step % write_frequency == 0: + feed_dict = { + self.input_tensor: inputs, + self.desired_person: desired_person, + self.learning_rate: learning_rate, + } + + summary, loss = self.sess.run([self.ALL_SUMMARIES, self.loss], feed_dict = feed_dict) + self.summary_writer.add_summary(summary, step) + self.summary_writer.flush() + + def save(self, checkpoint_path, name): + if not os.path.exists(checkpoint_path): + os.mkdir(checkpoint_path) + + checkpoint_name_path = os.path.join(checkpoint_path, '%s.ckpt' % name) + all_vars = tf.get_collection(tf.GraphKeys.MODEL_VARIABLES, scope = 'GaitNN') + + saver = tf.train.Saver(all_vars) + saver.save(self.sess, checkpoint_name_path) + + def restore(self, checkpoint_path): + all_vars = tf.get_collection(tf.GraphKeys.MODEL_VARIABLES, scope = 'GaitNN') + + saver = tf.train.Saver(all_vars) + saver.restore(self.sess, checkpoint_path) + + @staticmethod + def residual_block(net, ch = 256, ch_inner = 128, scope = None, reuse = None, stride = 1): + """ + Bottleneck v2 + """ + + with slim.arg_scope([layers.convolution2d], + activation_fn = None, + normalizer_fn = None): + with tf.variable_scope(scope, 'ResidualBlock', reuse = reuse): + in_net = net + + if stride > 1: + net = layers.convolution2d(net, ch, kernel_size = 1, stride = stride) + + in_net = layers.batch_norm(in_net) + in_net = tf.nn.relu(in_net) + in_net = layers.convolution2d(in_net, ch_inner, 1) + + in_net = layers.batch_norm(in_net) + in_net = tf.nn.relu(in_net) + in_net = layers.convolution2d(in_net, ch_inner, 3, stride = stride) + + in_net = layers.batch_norm(in_net) + in_net = tf.nn.relu(in_net) + in_net = layers.convolution2d(in_net, ch, 1, activation_fn = None) + + net = tf.nn.relu(in_net + net) + + return net + + @abstractmethod + def get_network(self, input_tensor, is_training, reuse = False): + pass + + +class GaitNetwork(GaitNN): + FEATURES = 512 + + def __init__(self, name = None, num_of_persons = 0, recurrent_unit = 'GRU', rnn_layers = 1, + reuse = False, is_training = False, input_net = None): + tf.set_random_seed(SEED) + + if num_of_persons <= 0 and is_training: + raise Exception('Parameter num_of_persons has to be greater than zero when thaining') + + self.num_of_persons = num_of_persons + self.rnn_layers = rnn_layers + self.recurrent_unit = recurrent_unit + + if input_net is None: + input_tensor = tf.placeholder( + dtype = tf.float32, + shape = (None, 17, 17, 32), + name = 'input_image') + else: + input_tensor = input_net + + super().__init__(name, input_tensor, self.FEATURES, num_of_persons, reuse, is_training) + + def get_network(self, input_tensor, is_training, reuse = False): + net = input_tensor + + with tf.variable_scope('GaitNN', reuse = reuse): + with slim.arg_scope(self.get_arg_scope(is_training)): + with tf.variable_scope('DownSampling'): + with tf.variable_scope('17x17'): + net = layers.convolution2d(net, num_outputs = 256, kernel_size = 1) + slim.repeat(net, 3, self.residual_block, ch = 256, ch_inner = 64) + + with tf.variable_scope('8x8'): + net = self.residual_block(net, ch = 512, ch_inner = 64, stride = 2) + slim.repeat(net, 2, self.residual_block, ch = 512, ch_inner = 128) + + with tf.variable_scope('4x4'): + net = self.residual_block(net, ch = 512, ch_inner = 128, stride = 2) + slim.repeat(net, 1, self.residual_block, ch = 512, ch_inner = 256) + + net = layers.convolution2d(net, num_outputs = 256, kernel_size = 1) + net = layers.convolution2d(net, num_outputs = 256, kernel_size = 3) + + with tf.variable_scope('FullyConnected'): + # net = tf.reduce_mean(net, [1, 2], name = 'GlobalPool') + net = layers.flatten(net) + net = layers.fully_connected(net, 512, activation_fn = None, normalizer_fn = None) + + with tf.variable_scope('Recurrent', initializer = tf.contrib.layers.xavier_initializer()): + cell_type = { + 'GRU': tf.nn.rnn_cell.GRUCell, + 'LSTM': tf.nn.rnn_cell.LSTMCell + } + + cell = cell_type[self.recurrent_unit](self.FEATURES) + cell = tf.nn.rnn_cell.MultiRNNCell([cell] * self.rnn_layers, state_is_tuple = True) + + net = tf.expand_dims(net, 0) + net, state = tf.nn.dynamic_rnn(cell, net, initial_state = cell.zero_state(1, dtype = tf.float32)) + net = tf.reshape(net, [-1, self.FEATURES]) + + # Temporal Avg-Pooling + gait_signature = tf.reduce_mean(net, 0) + + if is_training: + net = tf.expand_dims(gait_signature, 0) + net = layers.dropout(net, 0.7) + + with tf.variable_scope('Logits'): + net = layers.fully_connected(net, self.num_of_persons, activation_fn = None, + normalizer_fn = None) + + return net, gait_signature, state