--- a +++ b/trainers/VAE_You.py @@ -0,0 +1,173 @@ +from collections import defaultdict +from math import inf + +from tensorflow.python.ops.losses.losses_impl import Reduction + +from trainers import trainer_utils +from trainers.AEMODEL import Phase, update_log_dicts, indicate_early_stopping, AEMODEL +from trainers.DLMODEL import * + + +class VAE_You(AEMODEL): + class Config(AEMODEL.Config): + def __init__(self): + super().__init__('VAE_You') + self.restore_lr = 1e-3 + self.restore_steps = 150 + self.tv_lambda = 1.8 + + def __init__(self, sess, config, network=None): + super().__init__(sess, config, network) + self.x = tf.placeholder(tf.float32, [None, self.config.outputHeight, self.config.outputWidth, self.config.numChannels], name='x') + self.tv_lambda = tf.placeholder(tf.float32, shape=()) + + # Additional Parameters + self.restore_lr = self.config.restore_lr + self.restore_steps = self.config.restore_steps + self.tv_lambda_value = self.config.tv_lambda + + self.outputs = self.network(self.x, dropout_rate=self.dropout_rate, dropout=self.dropout, config=self.config) + self.reconstruction = self.outputs['x_hat'] + self.z_mu = self.outputs['z_mu'] + self.z_sigma = self.outputs['z_sigma'] + + # Print Stats + self.get_number_of_trainable_params() + # Instantiate Saver + self.saver = tf.train.Saver() + + def train(self, dataset): + # Determine trainable variables + self.variables = tf.get_collection(tf.GraphKeys.TRAINABLE_VARIABLES) + + # Build losses + self.losses['L1'] = tf.losses.absolute_difference(self.x, self.reconstruction, reduction=Reduction.NONE) + rec = tf.reduce_sum(self.losses['L1'], axis=[1, 2, 3]) + kl = 0.5 * tf.reduce_sum(tf.square(self.z_mu) + tf.square(self.z_sigma) - tf.log(tf.square(self.z_sigma)) - 1, axis=1) + self.losses['pixel_loss'] = rec + kl + self.losses['reconstructionLoss'] = tf.reduce_mean(rec) + self.losses['kl'] = tf.reduce_mean(kl) + self.losses['loss'] = tf.reduce_mean(rec + kl) + + # for restoration + self.losses['restore'] = self.tv_lambda * tf.image.total_variation(tf.subtract(self.x, self.reconstruction)) + self.losses['grads'] = tf.gradients(self.losses['pixel_loss'] + self.losses['restore'], self.x)[0] + + # Set the optimizer + optim = self.create_optimizer(self.losses['loss'], var_list=self.variables, learningrate=self.config.learningrate, + beta1=self.config.beta1, type=self.config.optimizer) + + # initialize all variables + tf.global_variables_initializer().run(session=self.sess) + + best_cost = inf + last_improvement = 0 + last_epoch = self.load_checkpoint() + + # Go go go! + for epoch in range(last_epoch, self.config.numEpochs): + ############ + # TRAINING # + ############ + self.process(dataset, epoch, Phase.TRAIN, optim) + + # Increment last_epoch counter and save model + last_epoch += 1 + self.save(self.checkpointDir, last_epoch) + + ############## + # VALIDATION # + ############## + val_scalars = self.process(dataset, epoch, Phase.VAL) + + best_cost, last_improvement, stop = indicate_early_stopping(val_scalars['loss'], best_cost, last_improvement) + if stop: + print('Early stopping was triggered due to no improvement over the last 5 epochs') + break + + if self.tv_lambda_value == -1 and self.restore_steps > 0: + ############## + # Determine lambda # + ############## + print('Determining best lambda') + self.determine_best_lambda(dataset) + + def process(self, dataset, epoch, phase: Phase, optim=None): + scalars = defaultdict(list) + visuals = [] + num_batches = dataset.num_batches(self.config.batchsize, set=phase.value) + for idx in range(0, num_batches): + batch, _, _ = dataset.next_batch(self.config.batchsize, set=phase.value) + + fetches = { + 'reconstruction': self.reconstruction, + **self.losses + } + if phase == Phase.TRAIN: + fetches['optimizer'] = optim + + feed_dict = { + self.x: batch, + self.tv_lambda: self.tv_lambda_value, + self.dropout: phase == Phase.TRAIN, + self.dropout_rate: self.config.dropout_rate + } + + run = self.sess.run(fetches, feed_dict=feed_dict) + + # Print to console + print(f'Epoch ({phase.value}): [{epoch:2d}] [{idx:4d}/{num_batches:4d}] loss: {run["loss"]:.8f}') + update_log_dicts(*trainer_utils.get_summary_dict(batch, run), scalars, visuals) + + self.log_to_tensorboard(epoch, scalars, visuals, phase) + return scalars + + def reconstruct(self, x, dropout=False): + if x.ndim < 4: + x = np.expand_dims(x, 0) + + restored = x.copy() + for step in range(self.restore_steps): + feed_dict = { + self.x: restored, + self.tv_lambda: self.tv_lambda_value, + self.dropout: dropout, # apply only during MC sampling. + self.dropout_rate: self.config.dropout_rate + } + run = self.sess.run({'grads': self.losses['grads']}, feed_dict=feed_dict) + gradients = run['grads'] + restored -= self.restore_lr * gradients + + results = { + 'reconstruction': restored + } + results['l1err'] = np.sum(np.abs(x - results['reconstruction'])) + results['l2err'] = np.sum(np.sqrt((x - results['reconstruction']) ** 2)) + + return results + + def determine_best_lambda(self, dataset): + lambdas = np.arange(20) / 10.0 + mean_errors = [] + fetches = self.losses + + for tv_lambda in lambdas: + errors = [] + for idx in range(int(dataset.num_batches(self.config.batchsize, set=Phase.VAL.value) * 0.2)): + batch, _, _ = dataset.next_batch(self.config.batchsize, set=Phase.VAL.value) + restored = batch.copy() + for step in range(self.restore_steps): + feed_dict = { + self.x: restored, + self.tv_lambda: tv_lambda, + self.dropout: False, + self.dropout_rate: self.config.dropout_rate + } + run = self.sess.run(fetches, feed_dict=feed_dict) + restored -= self.restore_lr * run['grads'] + errors.append(np.sum(np.abs(batch - restored))) + mean_error = np.mean(errors) + mean_errors.append(mean_error) + print(f'mean_error for lambda {tv_lambda}: {mean_error}') + self.tv_lambda_value = lambdas[mean_errors.index(min(mean_errors))] + print(f'Best lambda: {self.tv_lambda_value}')