#!/usr/bin/python3
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# -*- coding: utf-8 -*-
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# library modules
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from math import ceil
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import json
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import time
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import os
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import threading
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# External library modules
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import tensorflow as tf
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import numpy as np
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# local modules
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from data import LSVRC2010
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import logs
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class AlexNet:
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"""
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A tensorflow implementation of the paper:
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`AlexNet <https://papers.nips.cc/paper/4824-imagenet-classification-with-deep-convolutional-neural-networks.pdf>`_
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"""
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def __init__(self, path, batch_size, resume):
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"""
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Build the AlexNet model
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"""
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self.logger = logs.get_logger()
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self.resume = resume
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self.path = path
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self.batch_size = batch_size
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self.lsvrc2010 = LSVRC2010(self.path, batch_size)
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self.num_classes = len(self.lsvrc2010.wnid2label)
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self.lr = 0.001
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self.momentum = 0.9
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self.lambd = tf.constant(0.0005, name='lambda')
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self.input_shape = (None, 227, 227, 3)
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self.output_shape = (None, self.num_classes)
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self.logger.info("Creating placeholders for graph...")
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self.create_tf_placeholders()
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self.logger.info("Creating variables for graph...")
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self.create_tf_variables()
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self.logger.info("Initialize hyper parameters...")
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self.hyper_param = {}
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self.init_hyper_param()
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def create_tf_placeholders(self):
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"""
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Create placeholders for the graph.
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The input for these will be given while training or testing.
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"""
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self.input_image = tf.placeholder(tf.float32, shape=self.input_shape,
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name='input_image')
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self.labels = tf.placeholder(tf.float32, shape=self.output_shape,
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name='output')
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self.learning_rate = tf.placeholder(tf.float32, shape=(),
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name='learning_rate')
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self.dropout = tf.placeholder(tf.float32, shape=(),
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name='dropout')
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def create_tf_variables(self):
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"""
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Create variables for epoch, batch and global step
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"""
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self.global_step = tf.Variable(0, name='global_step', trainable=False)
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self.cur_epoch = tf.Variable(0, name='epoch', trainable=False)
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self.cur_batch = tf.Variable(0, name='batch', trainable=False)
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self.increment_epoch_op = tf.assign(self.cur_epoch, self.cur_epoch+1)
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self.increment_batch_op = tf.assign(self.cur_batch, self.cur_batch+1)
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self.init_batch_op = tf.assign(self.cur_batch, 0)
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def init_hyper_param(self):
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"""
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Store the hyper parameters.
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For each layer store number of filters(kernels)
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and filter size.
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If it's a fully connected layer then store the number of neurons.
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"""
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with open('hparam.json') as f:
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self.hyper_param = json.load(f)
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def get_filter(self, layer_num, layer_name):
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"""
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:param layer_num: Indicates the layer number in the graph
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:type layer_num: int
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:param layer_name: Name of the filter
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"""
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layer = 'L' + str(layer_num)
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filter_height, filter_width, in_channels = self.hyper_param[layer]['filter_size']
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out_channels = self.hyper_param[layer]['filters']
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return tf.Variable(tf.truncated_normal(
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[filter_height, filter_width, in_channels, out_channels],
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dtype = tf.float32, stddev = 1e-2), name = layer_name)
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def get_strides(self, layer_num):
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"""
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:param layer_num: Indicates the layer number in the graph
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:type layer_num: int
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"""
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layer = 'L' + str(layer_num)
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stride = self.hyper_param[layer]['stride']
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strides = [1, stride, stride, 1]
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return strides
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def get_bias(self, layer_num, value=0.0):
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"""
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Get the bias variable for current layer
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:param layer_num: Indicates the layer number in the graph
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:type layer_num: int
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"""
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layer = 'L' + str(layer_num)
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initial = tf.constant(value,
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shape=[self.hyper_param[layer]['filters']],
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name='C' + str(layer_num))
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return tf.Variable(initial, name='B' + str(layer_num))
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@property
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def l2_loss(self):
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"""
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Compute the l2 loss for all the weights
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"""
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conv_bias_names = ['B' + str(i) for i in range(1, 6)]
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weights = []
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for v in tf.trainable_variables():
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if 'biases' in v.name: continue
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if v.name.split(':')[0] in conv_bias_names: continue
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weights.append(v)
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return self.lambd * tf.add_n([tf.nn.l2_loss(weight) for weight in weights])
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def build_graph(self):
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"""
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Build the tensorflow graph for AlexNet.
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First 5 layers are Convolutional layers. Out of which
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first 2 and last layer will be followed by *max pooling*
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layers.
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Next 2 layers are fully connected layers.
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L1_conv -> L1_MP -> L2_conv -> L2_MP -> L3_conv
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-> L4_conv -> L5_conv -> L5_MP -> L6_FC -> L7_FC
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Where L1_conv -> Convolutional layer 1
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L5_MP -> Max pooling layer 5
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L7_FC -> Fully Connected layer 7
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Use `tf.nn.conv2d` to initialize the filters so
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as to reduce training time and `tf.layers.max_pooling2d`
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as we don't need to initialize in the pooling layer.
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"""
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# Layer 1 Convolutional layer
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filter1 = self.get_filter(1, 'L1_filter')
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l1_conv = tf.nn.conv2d(self.input_image, filter1,
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self.get_strides(1),
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padding = self.hyper_param['L1']['padding'],
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name='L1_conv')
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l1_conv = tf.add(l1_conv, self.get_bias(1))
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l1_conv = tf.nn.local_response_normalization(l1_conv,
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depth_radius=5,
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bias=2,
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alpha=1e-4,
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beta=.75)
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l1_conv = tf.nn.relu(l1_conv)
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# Layer 1 Max Pooling layer
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l1_MP = tf.layers.max_pooling2d(l1_conv,
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self.hyper_param['L1_MP']['filter_size'],
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self.hyper_param['L1_MP']['stride'],
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name='L1_MP')
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# Layer 2 Convolutional layer
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filter2 = self.get_filter(2, 'L2_filter')
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l2_conv = tf.nn.conv2d(l1_MP, filter2,
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self.get_strides(2),
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padding = self.hyper_param['L2']['padding'],
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name='L2_conv')
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l2_conv = tf.add(l2_conv, self.get_bias(2, 1.0))
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l2_conv = tf.nn.local_response_normalization(l2_conv,
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depth_radius=5,
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bias=2,
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alpha=1e-4,
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beta=.75)
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l2_conv = tf.nn.relu(l2_conv)
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# Layer 2 Max Pooling layer
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l2_MP = tf.layers.max_pooling2d(l2_conv,
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self.hyper_param['L2_MP']['filter_size'],
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self.hyper_param['L2_MP']['stride'],
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name='L2_MP')
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# Layer 3 Convolutional layer
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filter3 = self.get_filter(3, 'L3_filter')
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l3_conv = tf.nn.conv2d(l2_MP, filter3,
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self.get_strides(3),
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padding = self.hyper_param['L3']['padding'],
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name='L3_conv')
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l3_conv = tf.add(l3_conv, self.get_bias(3))
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l3_conv = tf.nn.relu(l3_conv)
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# Layer 4 Convolutional layer
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filter4 = self.get_filter(4, 'L4_filter')
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l4_conv = tf.nn.conv2d(l3_conv, filter4,
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self.get_strides(4),
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padding = self.hyper_param['L4']['padding'],
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name='L4_conv')
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l4_conv = tf.add(l4_conv, self.get_bias(4, 1.0))
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l4_conv = tf.nn.relu(l4_conv)
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# Layer 5 Convolutional layer
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filter5 = self.get_filter(5, 'L5_filter')
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l5_conv = tf.nn.conv2d(l4_conv, filter5,
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self.get_strides(5),
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padding = self.hyper_param['L5']['padding'],
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name='L5_conv')
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l5_conv = tf.add(l5_conv, self.get_bias(5, 1.0))
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l5_conv = tf.nn.relu(l5_conv)
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# Layer 5 Max Pooling layer
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l5_MP = tf.layers.max_pooling2d(l5_conv,
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self.hyper_param['L5_MP']['filter_size'],
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self.hyper_param['L5_MP']['stride'],
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name='L5_MP')
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flatten = tf.layers.flatten(l5_MP)
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# Layer 6 Fully connected layer
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l6_FC = tf.contrib.layers.fully_connected(flatten,
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self.hyper_param['FC6'])
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# Dropout layer
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l6_dropout = tf.nn.dropout(l6_FC, self.dropout,
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name='l6_dropout')
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# Layer 7 Fully connected layer
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self.l7_FC = tf.contrib.layers.fully_connected(l6_dropout,
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self.hyper_param['FC7'])
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# Dropout layer
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l7_dropout = tf.nn.dropout(self.l7_FC, self.dropout,
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name='l7_dropout')
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# final layer before softmax
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self.logits = tf.contrib.layers.fully_connected(l7_dropout,
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self.num_classes, None)
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# loss function
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loss_function = tf.nn.softmax_cross_entropy_with_logits(
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logits = self.logits,
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labels = self.labels
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)
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# total loss
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self.loss = tf.reduce_mean(loss_function) + self.l2_loss
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self.optimizer = tf.train.MomentumOptimizer(self.learning_rate, momentum=self.momentum)\
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.minimize(self.loss, global_step=self.global_step)
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correct = tf.equal(tf.argmax(self.logits, 1), tf.argmax(self.labels, 1))
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self.accuracy = tf.reduce_mean(tf.cast(correct, tf.float32))
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self.top5_correct = tf.nn.in_top_k(self.logits, tf.argmax(self.labels, 1), 5)
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self.top5_accuracy = tf.reduce_mean(tf.cast(self.top5_correct, tf.float32))
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self.add_summaries()
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def add_summaries(self):
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"""
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Add summaries for loss, top1 and top5 accuracies
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Add loss, top1 and top5 accuracies to summary files
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in order to visualize in tensorboard
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"""
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tf.summary.scalar('loss', self.loss)
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tf.summary.scalar('Top-1-Acc', self.accuracy)
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tf.summary.scalar('Top-5-Acc', self.top5_accuracy)
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self.merged = tf.summary.merge_all()
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def save_model(self, sess, saver):
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"""
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Save the current model
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:param sess: Session object
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:param saver: Saver object responsible to store
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"""
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model_base_path = os.path.join(os.getcwd(), 'model')
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if not os.path.exists(model_base_path):
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os.mkdir(model_base_path)
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model_save_path = os.path.join(os.getcwd(), 'model', 'model.ckpt')
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save_path = saver.save(sess, model_save_path)
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self.logger.info("Model saved in path: %s", save_path)
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def restore_model(self, sess, saver):
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"""
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Restore previously saved model
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:param sess: Session object
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:param saver: Saver object responsible to store
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"""
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model_base_path = os.path.join(os.getcwd(), 'model')
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model_restore_path = os.path.join(os.getcwd(), 'model', 'model.ckpt')
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saver.restore(sess, model_restore_path)
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self.logger.info("Model Restored from path: %s",
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model_restore_path)
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def get_summary_writer(self, sess):
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"""
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Get summary writer for training and validation
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Responsible for creating summary writer so it can
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write summaries to a file so it can be read by
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tensorboard later.
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"""
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if not os.path.exists(os.path.join('summary', 'train')):
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os.makedirs(os.path.join('summary', 'train'))
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if not os.path.exists(os.path.join('summary', 'val')):
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os.makedirs(os.path.join('summary', 'val'))
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return (tf.summary.FileWriter(os.path.join(os.getcwd(),
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'summary', 'train'),
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sess.graph),
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tf.summary.FileWriter(os.path.join(os.getcwd(),
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'summary', 'val'),
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sess.graph))
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def train(self, epochs, thread='false'):
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"""
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Train AlexNet.
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"""
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batch_step, val_step = 10, 500
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self.logger.info("Building the graph...")
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self.build_graph()
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init = tf.global_variables_initializer()
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saver = tf.train.Saver()
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with tf.Session(config=tf.ConfigProto(log_device_placement=True)) as sess:
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(summary_writer_train,
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summary_writer_val) = self.get_summary_writer(sess)
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if self.resume and os.path.exists(os.path.join(os.getcwd(),
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'model')):
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self.restore_model(sess, saver)
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else:
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sess.run(init)
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resume_batch = True
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best_loss = float('inf')
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while sess.run(self.cur_epoch) < epochs:
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losses = []
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accuracies = []
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epoch = sess.run(self.cur_epoch)
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if not self.resume or (
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self.resume and not resume_batch):
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sess.run(self.init_batch_op)
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resume_batch = False
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start = time.time()
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gen_batch = self.lsvrc2010.gen_batch
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for images, labels in gen_batch:
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batch_i = sess.run(self.cur_batch)
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# If it's resumed from stored model,
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# this will save from messing up the batch number
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# in subsequent epoch
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if batch_i >= ceil(len(self.lsvrc2010.image_names) / self.batch_size):
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break
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(_, global_step,
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_) = sess.run([self.optimizer,
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self.global_step, self.increment_batch_op],
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feed_dict = {
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self.input_image: images,
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self.labels: labels,
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self.learning_rate: self.lr,
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self.dropout: 0.5
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})
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if global_step == 150000:
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self.lr = 0.0001 # Halve the learning rate
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if batch_i % batch_step == 0:
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(summary, loss, acc, top5_acc, _top5,
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logits, l7_FC) = sess.run([self.merged, self.loss,
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self.accuracy, self.top5_accuracy,
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self.top5_correct,
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self.logits, self.l7_FC],
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feed_dict = {
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self.input_image: images,
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self.labels: labels,
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self.learning_rate: self.lr,
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self.dropout: 1.0
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})
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losses.append(loss)
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accuracies.append(acc)
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summary_writer_train.add_summary(summary, global_step)
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summary_writer_train.flush()
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end = time.time()
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try:
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self.logger.debug("l7 no of non zeros: %d", np.count_nonzero(l7_FC))
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true_idx = np.where(_top5[0]==True)[0][0]
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self.logger.debug("logit at %d: %s", true_idx,
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str(logits[true_idx]))
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except IndexError as ie:
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self.logger.debug(ie)
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self.logger.info("Time: %f Epoch: %d Batch: %d Loss: %f "
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"Avg loss: %f Accuracy: %f Avg Accuracy: %f "
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"Top 5 Accuracy: %f",
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end - start, epoch, batch_i,
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loss, sum(losses) / len(losses),
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acc, sum(accuracies) / len(accuracies),
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top5_acc)
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start = time.time()
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if batch_i % val_step == 0:
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images_val, labels_val = self.lsvrc2010.get_batch_val
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(summary, acc, top5_acc,
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loss) = sess.run([self.merged,
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self.accuracy,
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self.top5_accuracy, self.loss],
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feed_dict = {
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self.input_image: images_val,
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self.labels: labels_val,
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self.learning_rate: self.lr,
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self.dropout: 1.0
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})
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summary_writer_val.add_summary(summary, global_step)
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summary_writer_val.flush()
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self.logger.info("Validation - Accuracy: %f Top 5 Accuracy: %f Loss: %f",
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acc, top5_acc, loss)
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cur_loss = sum(losses) / len(losses)
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if cur_loss < best_loss:
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best_loss = cur_loss
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self.save_model(sess, saver)
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# Increase epoch number
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sess.run(self.increment_epoch_op)
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def test(self):
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step = 10
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self.logger_test = logs.get_logger('AlexNetTest', file_name='logs_test.log')
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self.logger_test.info("In Test: Building the graph...")
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self.build_graph()
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init = tf.global_variables_initializer()
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saver = tf.train.Saver()
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top1_count, top5_count, count = 0, 0, 0
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with tf.Session(config=tf.ConfigProto(log_device_placement=True)) as sess:
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self.restore_model(sess, saver)
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start = time.time()
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batch = self.lsvrc2010.gen_batch_test
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for i, (patches, labels) in enumerate(batch):
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count += patches[0].shape[0]
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avg_logits = np.zeros((patches[0].shape[0], self.num_classes))
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for patch in patches:
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logits = sess.run(self.logits,
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feed_dict = {
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self.input_image: patch,
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self.dropout: 1.0
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})
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avg_logits += logits
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avg_logits /= len(patches)
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top1_count += np.sum(np.argmax(avg_logits, 1) == labels)
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top5_count += np.sum(avg_logits.argsort()[:, -5:] == \
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np.repeat(labels, 5).reshape(patches[0].shape[0], 5))
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|
|
|
if i % step == 0:
|
|
end = time.time()
|
|
self.logger_test.info("Time: %f Step: %d "
|
|
"Avg Accuracy: %f "
|
|
"Avg Top 5 Accuracy: %f",
|
|
end - start, i,
|
|
top1_count / count,
|
|
top5_count / count)
|
|
start = time.time()
|
|
|
|
self.logger_test.info("Final - Avg Accuracy: %f "
|
|
"Avg Top 5 Accuracy: %f",
|
|
top1_count / count,
|
|
top5_count / count)
|
|
|
|
if __name__ == '__main__':
|
|
import argparse
|
|
parser = argparse.ArgumentParser()
|
|
parser.add_argument('image_path', metavar = 'image-path',
|
|
help = 'ImageNet dataset path')
|
|
parser.add_argument('--resume', metavar='resume',
|
|
type=lambda x: x != 'False', default=True,
|
|
required=False,
|
|
help='Resume training (True or False)')
|
|
parser.add_argument('--train', help='Train AlexNet')
|
|
parser.add_argument('--test', help='Test AlexNet')
|
|
args = parser.parse_args()
|
|
|
|
alexnet = AlexNet(args.image_path, batch_size=128, resume=args.resume)
|
|
|
|
if args.train == 'true':
|
|
alexnet.train(50)
|
|
elif args.test == 'true':
|
|
alexnet.test()
|