--- a +++ b/trainers/ceVAE.py @@ -0,0 +1,144 @@ +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 AEMODEL, Phase, indicate_early_stopping, update_log_dicts +from trainers.CE import retrieve_masked_batch +from trainers.DLMODEL import * + + +class ceVAE(AEMODEL): + class Config(AEMODEL.Config): + def __init__(self): + super().__init__('ceVAE') + self.use_gradient_based_restoration = True + + 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.x_ce = tf.placeholder(tf.float32, [None, self.config.outputHeight, self.config.outputWidth, self.config.numChannels], name='x_ce') + self.outputs = self.network(self.x, self.x_ce, dropout_rate=self.dropout_rate, dropout=self.dropout, config=self.config) + self.reconstruction = self.outputs['x_hat'] + self.reconstruction_ce = self.outputs['x_hat_ce'] + 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_vae'] = tf.losses.absolute_difference(self.x, self.reconstruction, reduction=Reduction.NONE) + self.losses['L1_ce'] = tf.losses.absolute_difference(self.x_ce, self.reconstruction_ce, reduction=Reduction.NONE) + self.losses['L1'] = 0.5 * (self.losses['L1_vae'] + self.losses['L1_ce']) + rec_vae = tf.reduce_sum(self.losses['L1_vae'], axis=[1, 2, 3]) + rec_ce = tf.reduce_sum(self.losses['L1_ce'], 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['Rec_ce'] = tf.reduce_mean(rec_ce) + self.losses['Rec_vae'] = tf.reduce_mean(rec_vae) + self.losses['reconstructionLoss'] = 0.5 * tf.reduce_mean(rec_vae + rec_ce) + self.losses['kl'] = tf.reduce_mean(kl) + self.losses['loss'] = tf.reduce_mean(rec_vae + kl + rec_ce) + self.losses['loss_vae'] = tf.reduce_mean(rec_vae + kl) + self.losses['anomaly'] = self.losses['L1_vae'] * tf.abs(tf.gradients(self.losses['loss_vae'], 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() + + visualization_keys = ['reconstruction', 'reconstruction_ce', 'anomaly'] + # Go go go! + for epoch in range(last_epoch, self.config.numEpochs): + ############ + # TRAINING # + ############ + self.process(dataset, epoch, Phase.TRAIN, optim, visualization_keys=visualization_keys) + + # 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, visualization_keys=visualization_keys) + + 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 + + def process(self, dataset, epoch, phase: Phase, optim=None, visualization_keys=None): + scalars = defaultdict(list) + visuals = [] + num_batches = dataset.num_batches(self.config.batchsize, set=phase.value) + for idx in range(0, num_batches): + batch, _, brainmasks = dataset.next_batch(self.config.batchsize, return_brainmask=True, set=phase.value) + + masked_batch = retrieve_masked_batch(batch, brainmasks) + + fetches = { + 'reconstruction': self.reconstruction, + 'reconstruction_ce': self.reconstruction_ce, + **self.losses + } + if phase == Phase.TRAIN: + fetches['optimizer'] = optim + + feed_dict = { + self.x: batch, + self.x_ce: masked_batch if phase == Phase.TRAIN else batch, + 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, visualization_keys), 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) + + fetches = { + 'reconstruction': self.reconstruction, + **self.losses + } + + feed_dict = { + self.x: x, + self.x_ce: x, + self.dropout: dropout, + self.dropout_rate: self.config.dropout_rate + } + results = self.sess.run(fetches, feed_dict=feed_dict) + + if self.config.use_gradient_based_restoration: + # this is actually not the real 'reconstruction' but for convenience we treat it like it + # would be to prevent changes in our evaluation script + results['reconstruction'] = x - self.config.use_gradient_based_restoration * results['anomaly'] + + results['l1err'] = np.sum(np.abs(x - results['reconstruction'])) + results['l2err'] = np.sum(np.sqrt((x - results['reconstruction']) ** 2)) + + return results