[Model] AlexNet

CaffeNet - a variant of AlexNet

Ref: Classification: Instant Recognition with Caffe

This is caffeNet

区别：https://github.com/BVLC/caffe/issues/4202

This is AlexNet.

单机版：http://www.cs.toronto.edu/~guerzhoy/tf_alexnet/myalexnet_forward_newtf.py

################################################################################
#Michael Guerzhoy and Davi Frossard, 2016
#AlexNet implementation in TensorFlow, with weights
#Details:
#http://www.cs.toronto.edu/~guerzhoy/tf_alexnet/
#
#With code from https://github.com/ethereon/caffe-tensorflow
#Model from  https://github.com/BVLC/caffe/tree/master/models/bvlc_alexnet
#Weights from Caffe converted using https://github.com/ethereon/caffe-tensorflow
#
#
################################################################################

from numpy import *
import os
#from pylab import *
import numpy as np
#import matplotlib.pyplot as plt
#import matplotlib.cbook as cbook
import time
from scipy.misc import imread
from scipy.misc import imresize
import matplotlib.image as mpimg
from scipy.ndimage import filters
import urllib
from numpy import random

import tensorflow as tf

from caffe_classes import class_names

train_x = zeros((1, 227,227,3)).astype(float32)
train_y = zeros((1, 1000))
xdim = train_x.shape[1:]
ydim = train_y.shape[1]

################################################################################
#Read Image, and change to BGR

im1 = (imread("laska.png")[:,:,:3]).astype(float32)
im1 = im1 - mean(im1)
im1[:, :, 0], im1[:, :, 2] = im1[:, :, 2], im1[:, :, 0]

im2 = (imread("poodle.png")[:,:,:3]).astype(float32)
im2[:, :, 0], im2[:, :, 2] = im2[:, :, 2], im2[:, :, 0]

################################################################################

# (self.feed('data')
#         .conv(11, 11, 96, 4, 4, padding='VALID', name='conv1')
#         .lrn(2, 2e-05, 0.75, name='norm1')
#         .max_pool(3, 3, 2, 2, padding='VALID', name='pool1')
#         .conv(5, 5, 256, 1, 1, group=2, name='conv2')
#         .lrn(2, 2e-05, 0.75, name='norm2')
#         .max_pool(3, 3, 2, 2, padding='VALID', name='pool2')
#         .conv(3, 3, 384, 1, 1, name='conv3')
#         .conv(3, 3, 384, 1, 1, group=2, name='conv4')
#         .conv(3, 3, 256, 1, 1, group=2, name='conv5')
#         .fc(4096, name='fc6')
#         .fc(4096, name='fc7')
#         .fc(1000, relu=False, name='fc8')
#         .softmax(name='prob'))

#In Python 3.5, change this to:
net_data = load(open("bvlc_alexnet.npy", "rb"), encoding="latin1").item()
#net_data = load("bvlc_alexnet.npy").item()

def conv(input, kernel, biases, k_h, k_w, c_o, s_h, s_w,  padding="VALID", group=1):
    '''From https://github.com/ethereon/caffe-tensorflow
    '''
    c_i = input.get_shape()[-1]
    assert c_i%group==0
    assert c_o%group==0
    convolve = lambda i, k: tf.nn.conv2d(i, k, [1, s_h, s_w, 1], padding=padding)

    if group==1:
        conv = convolve(input, kernel)
    else:
        input_groups =  tf.split(input, group, 3)   #tf.split(3, group, input)
        kernel_groups = tf.split(kernel, group, 3)  #tf.split(3, group, kernel)
        output_groups = [convolve(i, k) for i,k in zip(input_groups, kernel_groups)]
        conv = tf.concat(output_groups, 3)          #tf.concat(3, output_groups)
    return  tf.reshape(tf.nn.bias_add(conv, biases), [-1]+conv.get_shape().as_list()[1:])

x = tf.placeholder(tf.float32, (None,) + xdim)

#conv1
#conv(11, 11, 96, 4, 4, padding='VALID', name='conv1')
k_h = 11; k_w = 11; c_o = 96; s_h = 4; s_w = 4
conv1W = tf.Variable(net_data["conv1"][0])
conv1b = tf.Variable(net_data["conv1"][1])
conv1_in = conv(x, conv1W, conv1b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=1)
conv1 = tf.nn.relu(conv1_in)

#lrn1
#lrn(2, 2e-05, 0.75, name='norm1')
radius = 2; alpha = 2e-05; beta = 0.75; bias = 1.0
lrn1 = tf.nn.local_response_normalization(conv1,
                                                  depth_radius=radius,
                                                  alpha=alpha,
                                                  beta=beta,
                                                  bias=bias)

#maxpool1
#max_pool(3, 3, 2, 2, padding='VALID', name='pool1')
k_h = 3; k_w = 3; s_h = 2; s_w = 2; padding = 'VALID'
maxpool1 = tf.nn.max_pool(lrn1, ksize=[1, k_h, k_w, 1], strides=[1, s_h, s_w, 1], padding=padding)

#conv2
#conv(5, 5, 256, 1, 1, group=2, name='conv2')
k_h = 5; k_w = 5; c_o = 256; s_h = 1; s_w = 1; group = 2
conv2W = tf.Variable(net_data["conv2"][0])
conv2b = tf.Variable(net_data["conv2"][1])
conv2_in = conv(maxpool1, conv2W, conv2b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=group)
conv2 = tf.nn.relu(conv2_in)

#lrn2
#lrn(2, 2e-05, 0.75, name='norm2')
radius = 2; alpha = 2e-05; beta = 0.75; bias = 1.0
lrn2 = tf.nn.local_response_normalization(conv2,
                                                  depth_radius=radius,
                                                  alpha=alpha,
                                                  beta=beta,
                                                  bias=bias)

#maxpool2
#max_pool(3, 3, 2, 2, padding='VALID', name='pool2')
k_h = 3; k_w = 3; s_h = 2; s_w = 2; padding = 'VALID'
maxpool2 = tf.nn.max_pool(lrn2, ksize=[1, k_h, k_w, 1], strides=[1, s_h, s_w, 1], padding=padding)

#conv3
#conv(3, 3, 384, 1, 1, name='conv3')
k_h = 3; k_w = 3; c_o = 384; s_h = 1; s_w = 1; group = 1
conv3W = tf.Variable(net_data["conv3"][0])
conv3b = tf.Variable(net_data["conv3"][1])
conv3_in = conv(maxpool2, conv3W, conv3b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=group)
conv3 = tf.nn.relu(conv3_in)

#conv4
#conv(3, 3, 384, 1, 1, group=2, name='conv4')
k_h = 3; k_w = 3; c_o = 384; s_h = 1; s_w = 1; group = 2
conv4W = tf.Variable(net_data["conv4"][0])
conv4b = tf.Variable(net_data["conv4"][1])
conv4_in = conv(conv3, conv4W, conv4b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=group)
conv4 = tf.nn.relu(conv4_in)

#conv5
#conv(3, 3, 256, 1, 1, group=2, name='conv5')
k_h = 3; k_w = 3; c_o = 256; s_h = 1; s_w = 1; group = 2
conv5W = tf.Variable(net_data["conv5"][0])
conv5b = tf.Variable(net_data["conv5"][1])
conv5_in = conv(conv4, conv5W, conv5b, k_h, k_w, c_o, s_h, s_w, padding="SAME", group=group)
conv5 = tf.nn.relu(conv5_in)

#maxpool5
#max_pool(3, 3, 2, 2, padding='VALID', name='pool5')
k_h = 3; k_w = 3; s_h = 2; s_w = 2; padding = 'VALID'
maxpool5 = tf.nn.max_pool(conv5, ksize=[1, k_h, k_w, 1], strides=[1, s_h, s_w, 1], padding=padding)

#fc6
#fc(4096, name='fc6')
fc6W = tf.Variable(net_data["fc6"][0])
fc6b = tf.Variable(net_data["fc6"][1])
fc6 = tf.nn.relu_layer(tf.reshape(maxpool5, [-1, int(prod(maxpool5.get_shape()[1:]))]), fc6W, fc6b)

#fc7
#fc(4096, name='fc7')
fc7W = tf.Variable(net_data["fc7"][0])
fc7b = tf.Variable(net_data["fc7"][1])
fc7 = tf.nn.relu_layer(fc6, fc7W, fc7b)

#fc8
#fc(1000, relu=False, name='fc8')
fc8W = tf.Variable(net_data["fc8"][0])
fc8b = tf.Variable(net_data["fc8"][1])
fc8 = tf.nn.xw_plus_b(fc7, fc8W, fc8b)

#prob
#softmax(name='prob'))
prob = tf.nn.softmax(fc8)

init = tf.initialize_all_variables()
sess = tf.Session()
sess.run(init)

t = time.time()
output = sess.run(prob, feed_dict = {x:[im1,im2]})
################################################################################

#Output:

for input_im_ind in range(output.shape[0]):
    inds = argsort(output)[input_im_ind,:]
    print("Image", input_im_ind)
    for i in range(5):
        print(class_names[inds[-1-i]], output[input_im_ind, inds[-1-i]])

print(time.time()-t)

################################################################################
#Michael Guerzhoy and Davi Frossard, 2016
#AlexNet implementation in TensorFlow, with weights
#Details:
#http://www.cs.toronto.edu/~guerzhoy/tf_alexnet/
#
#With code from https://github.com/ethereon/caffe-tensorflow
#Model from  https://github.com/BVLC/caffe/tree/master/models/bvlc_alexnet
#Weights from Caffe converted using https://github.com/ethereon/caffe-tensorflow
#
#
################################################################################

此处推荐了将caffe model自动转为tensorflow的。

模型：

From: https://github.com/BVLC/caffe/tree/master/models/bvlc_alexnet

1. train_val.prototxt 

首先，train_val.prototxt文件是network配置文件。该文件是在训练的时候用的。

2.deploy.prototxt

该文件是在测试时使用的文件。

区别：

首先deploy.prototxt文件都是在train_val.prototxt文件的基础上删除了一些东西，所形成的。

由于两个文件的性质，train_val.prototxt文件里面训练的部分都会在deploy.prototxt文件中删除。

 

参数

• bvlc_alexnet.npy -- the weights; they need to be in the working directory [link]

 

Train: https://github.com/tensorflow/models/blob/master/research/slim/nets/alexnet.py

Test : https://github.com/tensorflow/models/blob/master/research/slim/nets/alexnet_test.py

# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Contains a model definition for AlexNet.

This work was first described in:
  ImageNet Classification with Deep Convolutional Neural Networks
  Alex Krizhevsky, Ilya Sutskever and Geoffrey E. Hinton

and later refined in:
  One weird trick for parallelizing convolutional neural networks
  Alex Krizhevsky, 2014

Here we provide the implementation proposed in "One weird trick" and not
"ImageNet Classification", as per the paper, the LRN layers have been removed.

Usage:
  with slim.arg_scope(alexnet.alexnet_v2_arg_scope()):
    outputs, end_points = alexnet.alexnet_v2(inputs)

@@alexnet_v2
"""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import tensorflow as tf

slim = tf.contrib.slim
trunc_normal = lambda stddev: tf.truncated_normal_initializer(0.0, stddev)

def alexnet_v2_arg_scope(weight_decay=0.0005):
  with slim.arg_scope([slim.conv2d, slim.fully_connected],
                      activation_fn=tf.nn.relu,
                      biases_initializer=tf.constant_initializer(0.1),
                      weights_regularizer=slim.l2_regularizer(weight_decay)):
    with slim.arg_scope([slim.conv2d], padding='SAME'):
      with slim.arg_scope([slim.max_pool2d], padding='VALID') as arg_sc:
        return arg_sc

def alexnet_v2(inputs,
               num_classes=1000,
               is_training=True,
               dropout_keep_prob=0.5,
               spatial_squeeze=True,
               scope='alexnet_v2'):
  """AlexNet version 2.

  Described in: http://arxiv.org/pdf/1404.5997v2.pdf
  Parameters from:
  github.com/akrizhevsky/cuda-convnet2/blob/master/layers/
  layers-imagenet-1gpu.cfg

  Note: All the fully_connected layers have been transformed to conv2d layers.
        To use in classification mode, resize input to 224x224. To use in fully
        convolutional mode, set spatial_squeeze to false.
        The LRN layers have been removed and change the initializers from
        random_normal_initializer to xavier_initializer.

  Args:
    inputs: a tensor of size [batch_size, height, width, channels].
    num_classes: number of predicted classes.
    is_training: whether or not the model is being trained.
    dropout_keep_prob: the probability that activations are kept in the dropout
      layers during training.
    spatial_squeeze: whether or not should squeeze the spatial dimensions of the
      outputs. Useful to remove unnecessary dimensions for classification.
    scope: Optional scope for the variables.

  Returns:
    the last op containing the log predictions and end_points dict.
  """
  with tf.variable_scope(scope, 'alexnet_v2', [inputs]) as sc:
    end_points_collection = sc.name + '_end_points'
    # Collect outputs for conv2d, fully_connected and max_pool2d.
    with slim.arg_scope([slim.conv2d, slim.fully_connected, slim.max_pool2d],
                        outputs_collections=[end_points_collection]):
      net = slim.conv2d(inputs, 64, [11, 11], 4, padding='VALID',
                        scope='conv1')
      net = slim.max_pool2d(net, [3, 3], 2, scope='pool1')
      net = slim.conv2d(net, 192, [5, 5], scope='conv2')
      net = slim.max_pool2d(net, [3, 3], 2, scope='pool2')
      net = slim.conv2d(net, 384, [3, 3], scope='conv3')
      net = slim.conv2d(net, 384, [3, 3], scope='conv4')
      net = slim.conv2d(net, 256, [3, 3], scope='conv5')
      net = slim.max_pool2d(net, [3, 3], 2, scope='pool5')

      # Use conv2d instead of fully_connected layers.
      with slim.arg_scope([slim.conv2d],
                          weights_initializer=trunc_normal(0.005),
                          biases_initializer=tf.constant_initializer(0.1)):
        net = slim.conv2d(net, 4096, [5, 5], padding='VALID',
                          scope='fc6')
        net = slim.dropout(net, dropout_keep_prob, is_training=is_training,
                           scope='dropout6')
        net = slim.conv2d(net, 4096, [1, 1], scope='fc7')
        net = slim.dropout(net, dropout_keep_prob, is_training=is_training,
                           scope='dropout7')
        net = slim.conv2d(net, num_classes, [1, 1],
                          activation_fn=None,
                          normalizer_fn=None,
                          biases_initializer=tf.zeros_initializer(),
                          scope='fc8')

      # Convert end_points_collection into a end_point dict.
      end_points = slim.utils.convert_collection_to_dict(end_points_collection)
      if spatial_squeeze:
        net = tf.squeeze(net, [1, 2], name='fc8/squeezed')
        end_points[sc.name + '/fc8'] = net
      return net, end_points
alexnet_v2.default_image_size = 224

From: http://vision.stanford.edu/teaching/cs231b_spring1415/slides/alexnet_tugce_kyunghee.pdf

LCN: 使用价值不大的结构

其中这个LRN层真是让人百思不得其解，搜索了下，给出的介绍比较少。为什么会比较少呢，搜索到最后我得出的结论是，这货似乎没什么多少卵用。

但似乎，在后来的设计中，这一层已经被其它种的Regularization技术，如drop out, batch normalization取代了。知道了这些，似乎也可以不那么纠结这个LRN了。

Batch normalization参见：http://www.cnblogs.com/hansjorn/p/6298576.html

单独列出来学习： 

SqueezeNet

http://www.jianshu.com/p/8e269451795d

http://blog.csdn.net/xbinworld/article/details/50897870

以上貌似是与AlexNet有关的两个网络设计，需要细看。