""" MIT License Copyright (c) 2017 Sadeep Jayasumana , Miguel Monteiro, Walter de Back Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ from keras.engine.topology import Layer import tensorflow as tf import lattice_filter_op_loader module = lattice_filter_op_loader.module class CRF_RNN_Layer(Layer): """ Implements the CRF-RNN layer. See https://github.com/sadeepj/crfasrnn_keras/blob/master/src/crfrnn_layer.py Based on GPU implementation here: https://github.com/MiguelMonteiro/CRFasRNNLayer Unaries and reference image must be provided in order: [unaries, ref_image] """ def __init__(self, image_dims, num_classes, theta_alpha, theta_beta, theta_gamma, num_iterations, **kwargs): self.image_dims = image_dims self.num_classes = num_classes self.theta_alpha = theta_alpha self.theta_beta = theta_beta self.theta_gamma = theta_gamma self.num_iterations = num_iterations self.spatial_ker_weights = None self.bilateral_ker_weights = None self.compatibility_matrix = None super(CRF_RNN_Layer, self).__init__(**kwargs) def build(self, input_shape): self.spatial_ker_weights = self.add_weight(name='spatial_ker_weights', shape=(self.num_classes,), initializer=tf.initializers.truncated_normal(mean=0, stddev=0.1), trainable=True) self.spatial_ker_weights = tf.diag(self.spatial_ker_weights) self.bilateral_ker_weights = self.add_weight(name='bilateral_ker_weights', shape=(self.num_classes,), initializer=tf.initializers.truncated_normal(mean=0, stddev=0.1), trainable=True) self.bilateral_ker_weights = tf.diag(self.bilateral_ker_weights) self.compatibility_matrix = self.add_weight(name='compatibility_matrix', shape=(self.num_classes, self.num_classes), initializer=tf.initializers.truncated_normal(mean=0, stddev=0.1), trainable=True) super(CRF_RNN_Layer, self).build(input_shape) def call(self, inputs, **kwargs): unaries = inputs[0] reference_image = inputs[1] # Prepare filter normalization coefficients unaries_shape = unaries.get_shape() q_values = unaries for i in range(self.num_iterations): q_values = tf.nn.softmax(q_values) # Spatial filtering spatial_out = module.lattice_filter(q_values, reference_image, bilateral=False, theta_gamma=self.theta_gamma) # Bilateral filtering bilateral_out = module.lattice_filter(q_values, reference_image, bilateral=True, theta_alpha=self.theta_alpha, theta_beta=self.theta_beta) # Weighting filter outputs message_passing = tf.matmul(self.spatial_ker_weights, tf.transpose(tf.reshape(spatial_out, (-1, self.num_classes)))) + \ tf.matmul(self.bilateral_ker_weights, tf.transpose(tf.reshape(bilateral_out, (-1, self.num_classes)))) # Compatibility transform pairwise = tf.matmul(self.compatibility_matrix, message_passing) # Adding unary potentials pairwise = tf.reshape(tf.transpose(pairwise), unaries_shape) q_values = unaries - pairwise return q_values def compute_output_shape(self, input_shape): return input_shape