reid-strong-baseline/modeling/baseline.py

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2019-03-17 15:16:48 +08:00
# encoding: utf-8
"""
@author: liaoxingyu
@contact: sherlockliao01@gmail.com
"""
import torch
from torch import nn
from .backbones.resnet import ResNet
def weights_init_kaiming(m):
classname = m.__class__.__name__
if classname.find('Linear') != -1:
nn.init.kaiming_normal_(m.weight, a=0, mode='fan_out')
nn.init.constant_(m.bias, 0.0)
elif classname.find('Conv') != -1:
nn.init.kaiming_normal_(m.weight, a=0, mode='fan_in')
if m.bias is not None:
nn.init.constant_(m.bias, 0.0)
elif classname.find('BatchNorm') != -1:
if m.affine:
nn.init.constant_(m.weight, 1.0)
nn.init.constant_(m.bias, 0.0)
def weights_init_classifier(m):
classname = m.__class__.__name__
if classname.find('Linear') != -1:
nn.init.normal_(m.weight, std=0.001)
if m.bias:
nn.init.constant_(m.bias, 0.0)
class Baseline(nn.Module):
in_planes = 2048
def __init__(self, num_classes, last_stride, model_path, neck, neck_feat):
super(Baseline, self).__init__()
self.base = ResNet(last_stride)
self.base.load_param(model_path)
self.gap = nn.AdaptiveAvgPool2d(1)
# self.gap = nn.AdaptiveMaxPool2d(1)
self.num_classes = num_classes
self.neck = neck
self.neck_feat = neck_feat
if self.neck == 'no':
self.classifier = nn.Linear(self.in_planes, self.num_classes)
# self.classifier = nn.Linear(self.in_planes, self.num_classes, bias=False) # new add by luo
# self.classifier.apply(weights_init_classifier) # new add by luo
elif self.neck == 'bnneck':
self.bottleneck = nn.BatchNorm1d(self.in_planes)
self.bottleneck.bias.requires_grad_(False) # no shift
self.classifier = nn.Linear(self.in_planes, self.num_classes, bias=False)
self.bottleneck.apply(weights_init_kaiming)
self.classifier.apply(weights_init_classifier)
def forward(self, x):
global_feat = self.gap(self.base(x)) # (b, 2048, 1, 1)
global_feat = global_feat.view(global_feat.shape[0], -1) # flatten to (bs, 2048)
if self.neck == 'no':
feat = global_feat
elif self.neck == 'bnneck':
feat = self.bottleneck(global_feat) # normalize for angular softmax
if self.training:
cls_score = self.classifier(feat)
return cls_score, global_feat # global feature for triplet loss
else:
if self.neck_feat == 'after':
# print("Test with feature after BN")
return feat
else:
# print("Test with feature before BN")
return global_feat
def load_param(self, trained_path):
param_dict = torch.load(trained_path)
for i in param_dict:
if 'classifier' in i:
continue
self.state_dict()[i].copy_(param_dict[i])