arcface 问题（精度为 0）
issue with arcface ( 0 accuracy)
大家好，我参加了大学级别的图像识别比赛。
在测试中，他们会给出两张图像（人脸），我的模型需要检测这两张图像是否是同一个人
我的模型是带有 IR 块和 SE 块的 resnet18。它将使用 Arcface 损失。
我只能用MS1M数据集总共86876类
问题是loss越来越好，但是accuracy是0，没有变化
这是我正在处理的部分代码。
火车
def train_model(model, net, criterion, optimizer, scheduler, num_epochs=25):
since = time.time()
best_model_wts = copy.deepcopy(model.state_dict())
best_acc = 0.0
for epoch in range(num_epochs):
print('Epoch {}/{}'.format(epoch, num_epochs - 1))
print('-' * 10)
for phase in ['train']:
if phase == 'train':
model.train() # Set model to training mode
running_loss = 0.0
running_corrects = 0
# Iterate over data.
for inputs, labels in notebook.tqdm(dataloader):
inputs = inputs.to(device)
labels = labels.to(device).long()
# zero the parameter gradients
optimizer.zero_grad()
# forward
# track history if only in train
with torch.set_grad_enabled(phase == 'train'):
features = model(inputs)
outputs = net(features, labels)
_, preds = torch.max(outputs, 1)
loss = criterion(outputs, labels)
# backward + optimize only if in training phase
if phase == 'train':
loss.backward()
optimizer.step()
# statistics
running_loss += loss.item() * inputs.size(0)
running_corrects += torch.sum(preds == labels.data)
if phase == 'train':
scheduler.step()
epoch_loss = running_loss / len(dataloader)
epoch_acc = running_corrects.double() / len(dataloader)
print('{} Loss: {:.4f} Acc: {:.4f}'.format(
phase, epoch_loss, epoch_acc))
# deep copy the model
if phase == 'train' and epoch_acc > best_acc:
best_acc = epoch_acc
best_model_wts = copy.deepcopy(model.state_dict())
torch.save({'epoch': epoch,
'mode_state_dict': model.state_dict(),
'fc_state_dict': net.state_dict(),
'optimizer_state_dict': optimizer.state_dict(),
'scheduler': scheduler.state_dict(), # HERE IS THE CHANGE
}, f'/content/drive/MyDrive/inha_data/training_saver/training_stat{epoch}.pth')
print(f'finished {epoch} and saved model_save_{epoch}.pt')
print()
time_elapsed = time.time() - since
print('Training complete in {:.0f}m {:.0f}s'.format(
time_elapsed // 60, time_elapsed % 60))
print('Best train Acc: {:4f}'.format(best_acc))
# load best model weights
model.load_state_dict(best_model_wts)
torch.save(model.state_dict(), 'model_save.pt')
return model
参数
train_dataset = MS1MDataset('train')
dataloader = torch.utils.data.DataLoader(train_dataset, batch_size=128, shuffle=True,num_workers=4)
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu") # 디바이스 설정
num_classes = 86876
# normal classifier
# net = nn.Sequential(nn.Linear(512, num_classes))
# Feature extractor backbone, input is 112x112 image output is 512 feature vector
model_ft = resnet18(True)
#set metric
metric_fc = metrics.ArcMarginProduct(512, num_classes, s = 30.0, m = 0.50, easy_margin = False)
metric_fc.to(device)
# net = net.to(device)
model_ft = model_ft.to(device)
criterion = nn.CrossEntropyLoss()
# Observe that all parameters are being optimized
optimizer_ft = torch.optim.Adam([{'params': model_ft.parameters()}, {'params': metric_fc.parameters()}],
lr=0.1)
# Decay LR by a factor of 0.1 every 7 epochs
exp_lr_scheduler = lr_scheduler.StepLR(optimizer_ft, step_size=4, gamma=0.1)
圆弧面
from __future__ import print_function
from __future__ import division
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.nn import Parameter
import math
class ArcMarginProduct(nn.Module):
r"""Implement of large margin arc distance: :
Args:
in_features: size of each input sample
out_features: size of each output sample
s: norm of input feature
m: margin
cos(theta + m)
"""
def __init__(self, in_features, out_features, s=30.0, m=0.50, easy_margin=False):
super(ArcMarginProduct, self).__init__()
self.in_features = in_features
self.out_features = out_features
self.s = s
self.m = m
self.weight = Parameter(torch.FloatTensor(out_features, in_features))
nn.init.xavier_uniform_(self.weight)
self.easy_margin = easy_margin
self.cos_m = math.cos(m)
self.sin_m = math.sin(m)
self.th = math.cos(math.pi - m)
self.mm = math.sin(math.pi - m) * m
def forward(self, input, label):
# --------------------------- cos(theta) & phi(theta) ---------------------------
cosine = F.linear(F.normalize(input), F.normalize(self.weight))
sine = torch.sqrt((1.0 - torch.pow(cosine, 2)).clamp(0, 1))
phi = cosine * self.cos_m - sine * self.sin_m
if self.easy_margin:
phi = torch.where(cosine > 0, phi, cosine)
else:
phi = torch.where(cosine > self.th, phi, cosine - self.mm)
# --------------------------- convert label to one-hot ---------------------------
# one_hot = torch.zeros(cosine.size(), requires_grad=True, device='cuda')
one_hot = torch.zeros(cosine.size(), device='cuda')
one_hot.scatter_(1, label.view(-1, 1).long(), 1)
# -------------torch.where(out_i = {x_i if condition_i else y_i) -------------
output = (one_hot * phi) + ((1.0 - one_hot) * cosine) # you can use torch.where if your torch.__version__ is 0.4
output *= self.s
# print(output)
return output
数据集
data_transforms = {
'train': transforms.Compose([
transforms.RandomHorizontalFlip(),
transforms.ColorJitter(brightness=0.125, contrast=0.125, saturation=0.125),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
]),
}
#train_ms1_data = torchvision.datasets.ImageFolder('/content/drive/MyDrive/inha_data/train', transform = data_transforms)
class MS1MDataset(Dataset):
def __init__(self,split):
self.file_list = '/content/drive/MyDrive/inha_data/ID_List.txt'
self.images = []
self.labels = []
self.transformer = data_transforms['train']
with open(self.file_list) as f:
files = f.read().splitlines()
for i, fi in enumerate(files):
fi = fi.split()
image = "/content/" + fi[1]
label = int(fi[0])
self.images.append(image)
self.labels.append(label)
def __getitem__(self, index):
img = Image.open(self.images[index])
img = self.transformer(img)
label = self.labels[index]
return img, label
def __len__(self):
return len(self.images)
ArcFace中可以尝试使用较小的m，甚至是负值。
大家好，我参加了大学级别的图像识别比赛。
在测试中，他们会给出两张图像（人脸），我的模型需要检测这两张图像是否是同一个人
我的模型是带有 IR 块和 SE 块的 resnet18。它将使用 Arcface 损失。
我只能用MS1M数据集总共86876类
问题是loss越来越好，但是accuracy是0，没有变化
这是我正在处理的部分代码。
火车
def train_model(model, net, criterion, optimizer, scheduler, num_epochs=25):
since = time.time()
best_model_wts = copy.deepcopy(model.state_dict())
best_acc = 0.0
for epoch in range(num_epochs):
print('Epoch {}/{}'.format(epoch, num_epochs - 1))
print('-' * 10)
for phase in ['train']:
if phase == 'train':
model.train() # Set model to training mode
running_loss = 0.0
running_corrects = 0
# Iterate over data.
for inputs, labels in notebook.tqdm(dataloader):
inputs = inputs.to(device)
labels = labels.to(device).long()
# zero the parameter gradients
optimizer.zero_grad()
# forward
# track history if only in train
with torch.set_grad_enabled(phase == 'train'):
features = model(inputs)
outputs = net(features, labels)
_, preds = torch.max(outputs, 1)
loss = criterion(outputs, labels)
# backward + optimize only if in training phase
if phase == 'train':
loss.backward()
optimizer.step()
# statistics
running_loss += loss.item() * inputs.size(0)
running_corrects += torch.sum(preds == labels.data)
if phase == 'train':
scheduler.step()
epoch_loss = running_loss / len(dataloader)
epoch_acc = running_corrects.double() / len(dataloader)
print('{} Loss: {:.4f} Acc: {:.4f}'.format(
phase, epoch_loss, epoch_acc))
# deep copy the model
if phase == 'train' and epoch_acc > best_acc:
best_acc = epoch_acc
best_model_wts = copy.deepcopy(model.state_dict())
torch.save({'epoch': epoch,
'mode_state_dict': model.state_dict(),
'fc_state_dict': net.state_dict(),
'optimizer_state_dict': optimizer.state_dict(),
'scheduler': scheduler.state_dict(), # HERE IS THE CHANGE
}, f'/content/drive/MyDrive/inha_data/training_saver/training_stat{epoch}.pth')
print(f'finished {epoch} and saved model_save_{epoch}.pt')
print()
time_elapsed = time.time() - since
print('Training complete in {:.0f}m {:.0f}s'.format(
time_elapsed // 60, time_elapsed % 60))
print('Best train Acc: {:4f}'.format(best_acc))
# load best model weights
model.load_state_dict(best_model_wts)
torch.save(model.state_dict(), 'model_save.pt')
return model
参数
train_dataset = MS1MDataset('train')
dataloader = torch.utils.data.DataLoader(train_dataset, batch_size=128, shuffle=True,num_workers=4)
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu") # 디바이스 설정
num_classes = 86876
# normal classifier
# net = nn.Sequential(nn.Linear(512, num_classes))
# Feature extractor backbone, input is 112x112 image output is 512 feature vector
model_ft = resnet18(True)
#set metric
metric_fc = metrics.ArcMarginProduct(512, num_classes, s = 30.0, m = 0.50, easy_margin = False)
metric_fc.to(device)
# net = net.to(device)
model_ft = model_ft.to(device)
criterion = nn.CrossEntropyLoss()
# Observe that all parameters are being optimized
optimizer_ft = torch.optim.Adam([{'params': model_ft.parameters()}, {'params': metric_fc.parameters()}],
lr=0.1)
# Decay LR by a factor of 0.1 every 7 epochs
exp_lr_scheduler = lr_scheduler.StepLR(optimizer_ft, step_size=4, gamma=0.1)
圆弧面
from __future__ import print_function
from __future__ import division
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.nn import Parameter
import math
class ArcMarginProduct(nn.Module):
r"""Implement of large margin arc distance: :
Args:
in_features: size of each input sample
out_features: size of each output sample
s: norm of input feature
m: margin
cos(theta + m)
"""
def __init__(self, in_features, out_features, s=30.0, m=0.50, easy_margin=False):
super(ArcMarginProduct, self).__init__()
self.in_features = in_features
self.out_features = out_features
self.s = s
self.m = m
self.weight = Parameter(torch.FloatTensor(out_features, in_features))
nn.init.xavier_uniform_(self.weight)
self.easy_margin = easy_margin
self.cos_m = math.cos(m)
self.sin_m = math.sin(m)
self.th = math.cos(math.pi - m)
self.mm = math.sin(math.pi - m) * m
def forward(self, input, label):
# --------------------------- cos(theta) & phi(theta) ---------------------------
cosine = F.linear(F.normalize(input), F.normalize(self.weight))
sine = torch.sqrt((1.0 - torch.pow(cosine, 2)).clamp(0, 1))
phi = cosine * self.cos_m - sine * self.sin_m
if self.easy_margin:
phi = torch.where(cosine > 0, phi, cosine)
else:
phi = torch.where(cosine > self.th, phi, cosine - self.mm)
# --------------------------- convert label to one-hot ---------------------------
# one_hot = torch.zeros(cosine.size(), requires_grad=True, device='cuda')
one_hot = torch.zeros(cosine.size(), device='cuda')
one_hot.scatter_(1, label.view(-1, 1).long(), 1)
# -------------torch.where(out_i = {x_i if condition_i else y_i) -------------
output = (one_hot * phi) + ((1.0 - one_hot) * cosine) # you can use torch.where if your torch.__version__ is 0.4
output *= self.s
# print(output)
return output
数据集
data_transforms = {
'train': transforms.Compose([
transforms.RandomHorizontalFlip(),
transforms.ColorJitter(brightness=0.125, contrast=0.125, saturation=0.125),
transforms.ToTensor(),
transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
]),
}
#train_ms1_data = torchvision.datasets.ImageFolder('/content/drive/MyDrive/inha_data/train', transform = data_transforms)
class MS1MDataset(Dataset):
def __init__(self,split):
self.file_list = '/content/drive/MyDrive/inha_data/ID_List.txt'
self.images = []
self.labels = []
self.transformer = data_transforms['train']
with open(self.file_list) as f:
files = f.read().splitlines()
for i, fi in enumerate(files):
fi = fi.split()
image = "/content/" + fi[1]
label = int(fi[0])
self.images.append(image)
self.labels.append(label)
def __getitem__(self, index):
img = Image.open(self.images[index])
img = self.transformer(img)
label = self.labels[index]
return img, label
def __len__(self):
return len(self.images)
ArcFace中可以尝试使用较小的m，甚至是负值。