import numpy as np
import torch
from torch import nn
from torch.autograd import Variable
def conv_relu(in_channel, out_channel, kernel, stride=1, padding=0):
layer = nn.Sequential(
nn.Conv2d(in_channel, out_channel, kernel, stride, padding),
nn.BatchNorm2d(out_channel, eps=1e-3),
nn.ReLU(True)
)
return layer
class inception(nn.Module):
def __init__(self,in_channel,out1_1,out2_1,out2_3,out3_1,out3_5,out4_1):
super(inception,self).__init__()
#第一条路
self.branch1_1 = conv_relu(in_channel,out1_1,1)
#第二条路
self.branch3_3 = nn.Sequential(
conv_relu(in_channel, out2_1, 1),
conv_relu(out2_1, out2_3, 3, padding=1)
)
#第三条路
self.branch5_5 = nn.Sequential(
conv_relu(in_channel, out3_1, 1),
conv_relu(out3_1, out3_5, 5, padding=2)
)
#第四条路
self.branch_pool = nn.Sequential(
nn.MaxPool2d(3, stride=1, padding=1),
conv_relu(in_channel, out4_1, 1)
)
def forward(self, x):
f1 = self.branch1_1(x)
f2 = self.branch3_3(x)
f3 = self.branch5_5(x)
f4 = self.branch_pool(x)
output = torch.cat((f1, f2, f3, f4), dim=1)
return output
class googlenet(nn.Module):
def __init__(self, in_channel, num_classes, verbose=False):
super(googlenet, self).__init__()
self.verbose = verbose
self.block1 = nn.Sequential(
conv_relu(in_channel, out_channel=64, kernel=7, stride=2, padding=3),
nn.MaxPool2d(3,2)
)
self.block2 = nn.Sequential(
conv_relu(64, 64, kernel=1),
conv_relu(64, 192, kernel=3, padding=1),
nn.MaxPool2d(3, 2)
)
self.block3 = nn.Sequential(
inception(192, 64, 96, 128, 16, 32, 32),
inception(256, 128, 128, 192, 32, 96, 64),
nn.MaxPool2d(3, 2)
)
self.block4 = nn.Sequential(
inception(480, 192, 96, 208, 16, 48, 64),
inception(512, 160, 112, 224, 24, 64, 64),
inception(512, 128, 128, 256, 24, 64, 64),
inception(512, 112, 144, 288, 32, 64, 64),
inception(528, 256, 160, 320, 32, 128, 128),
nn.MaxPool2d(3, 2)
)
self.block5 = nn.Sequential(
inception(832, 256, 160, 320, 32, 128, 128),
inception(832, 384, 182, 384, 48, 128, 128),
nn.AvgPool2d(2)
)
self.classifier = nn.Linear(1024, num_classes)
def forward(self, x):
x = self.block1(x)
if self.verbose:
print('block 1 output: {}'.format(x.shape))
x = self.block2(x)
if self.verbose:
print('block 2 output: {}'.format(x.shape))
x = self.block3(x)
if self.verbose:
print('block 3 output: {}'.format(x.shape))
x = self.block4(x)
if self.verbose:
print('block 4 output: {}'.format(x.shape))
x = self.block5(x)
if self.verbose:
print('block 5 output: {}'.format(x.shape))
x = x.view(x.shape[0], -1)
x = self.classifier(x)
return x
test_net = googlenet(3, 10, True)
test_x = Variable(torch.zeros(1, 3, 96, 96))
test_y = test_net(test_x)
print('output: {}'.format(test_y.shape))
