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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
CUT L通道 训练脚本
==================
仅对车牌 L (亮度) 通道做纹理迁移训练,a,b 颜色通道不动。
用法:
python train.py \
--domain-a ./gan_data/domain_A_synthetic/police \
--domain-b ./gan_data/domain_B_real \
--epochs 100 \
--batch 4 \
--output ./output/cut_police
"""
import os
import sys
import argparse
import time
from pathlib import Path
import torch
import torch.nn as nn
import torch.optim as optim
# 添加 tools 目录到路径
sys.path.insert(0, str(Path(__file__).resolve().parent))
from models import (
LChannelGenerator, PatchGANDiscriminator,
PatchNCELoss, init_weights, count_params,
)
from dataset import make_loader
def train(args):
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
print(f"Device: {device}")
# ---- 数据 ----
loader_a = make_loader(args.domain_a, args.batch, (args.img_w, args.img_h),
is_real=False, num_workers=args.workers)
loader_b = make_loader(args.domain_b, args.batch, (args.img_w, args.img_h),
is_real=True, num_workers=args.workers)
print(f"Domain A (合成): {len(loader_a.dataset)} 张")
print(f"Domain B (真实): {len(loader_b.dataset)} 张")
print(f"Batch size: {args.batch}")
print(f"Epochs: {args.epochs}")
# ---- 模型 ----
G = LChannelGenerator(n_res=args.n_res).to(device)
D = PatchGANDiscriminator().to(device)
init_weights(G)
init_weights(D)
print(f"G params: {count_params(G):,}")
print(f"D params: {count_params(D):,}")
# ---- 损失 & 优化器 ----
criterion_gan = nn.MSELoss() # LSGAN
criterion_nce = PatchNCELoss(
nce_layers=args.nce_layers,
nce_t=args.nce_t,
n_patches=args.n_patches,
).to(device)
criterion_idt = nn.L1Loss()
opt_G = optim.Adam(G.parameters(), lr=args.lr, betas=(0.5, 0.999))
opt_D = optim.Adam(D.parameters(), lr=args.lr, betas=(0.5, 0.999))
# ---- 日志 ----
os.makedirs(args.output, exist_ok=True)
# ---- 训练循环 ----
for epoch in range(1, args.epochs + 1):
epoch_start = time.time()
G_loss_total = 0.0
D_loss_total = 0.0
n_batches = 0
for real_a, real_b in zip(loader_a, loader_b):
real_a = real_a.to(device) # (B, 1, H, W) 合成L
real_b = real_b.to(device) # (B, 1, H, W) 真实L
B = real_a.size(0)
# ---- 1. 更新 D ----
fake_b = G(real_a).detach()
# G 不用返回特征
pred_real = D(real_b)
pred_fake = D(fake_b)
loss_D_real = criterion_gan(pred_real,
torch.ones_like(pred_real))
loss_D_fake = criterion_gan(pred_fake,
torch.zeros_like(pred_fake))
loss_D = (loss_D_real + loss_D_fake) * 0.5
opt_D.zero_grad()
loss_D.backward()
opt_D.step()
# ---- 2. 更新 G ----
fake_b, feat_q = G(real_a, return_features=True)
# GAN loss
pred_fake = D(fake_b)
loss_G_gan = criterion_gan(pred_fake,
torch.ones_like(pred_fake))
# PatchNCE loss (对比学习)
_, feat_k = G(real_b, return_features=True)
loss_G_nce = criterion_nce(feat_q, feat_k)
# Identity loss: 裁剪输出到输入尺寸(UNet可能多出几像素)
identity = G(real_a)
if identity.shape != real_a.shape:
identity = identity[:, :, :real_a.shape[2], :real_a.shape[3]]
loss_G_idt = criterion_idt(identity, real_a) * args.lambda_idt
loss_G = loss_G_gan + loss_G_nce * args.lambda_nce + loss_G_idt
opt_G.zero_grad()
loss_G.backward()
opt_G.step()
G_loss_total += loss_G.item()
D_loss_total += loss_D.item()
n_batches += 1
# ---- Epoch 统计 ----
G_avg = G_loss_total / max(n_batches, 1)
D_avg = D_loss_total / max(n_batches, 1)
elapsed = time.time() - epoch_start
print(f"Epoch {epoch:3d}/{args.epochs} | "
f"G: {G_avg:.4f} D: {D_avg:.4f} | "
f"{elapsed:.1f}s")
pass # 日志仅print,不使用tensorboard
# ---- 保存 ----
if epoch % args.save_every == 0:
ckpt = {
'epoch': epoch,
'G_state': G.state_dict(),
'D_state': D.state_dict(),
'opt_G': opt_G.state_dict(),
'opt_D': opt_D.state_dict(),
}
torch.save(ckpt, os.path.join(args.output, f'epoch_{epoch}.pth'))
# 最终保存
final_ckpt = {
'G_state': G.state_dict(),
'D_state': D.state_dict(),
}
torch.save(final_ckpt, os.path.join(args.output, 'final.pth'))
print(f"\n训练完成! 模型保存在: {args.output}")
def main():
parser = argparse.ArgumentParser(description='CUT L通道训练')
# 数据
parser.add_argument('--domain-a', type=str, required=True,
help='合成车牌目录')
parser.add_argument('--domain-b', type=str, required=True,
help='真实车牌目录')
# 训练
parser.add_argument('--epochs', type=int, default=100)
parser.add_argument('--batch', type=int, default=4)
parser.add_argument('--lr', type=float, default=2e-4)
parser.add_argument('--workers', type=int, default=2)
# 模型
parser.add_argument('--n-res', type=int, default=6,
help='残差块数量')
# 损失权重
parser.add_argument('--lambda-nce', type=float, default=1.0)
parser.add_argument('--lambda-idt', type=float, default=0.5)
# PatchNCE
parser.add_argument('--nce-layers', type=int, nargs='+', default=[0, 1, 2])
parser.add_argument('--nce-t', type=float, default=0.07)
parser.add_argument('--n-patches', type=int, default=128)
# 保存
parser.add_argument('--output', type=str, default='./output/cut_train')
parser.add_argument('--img-w', type=int, default=220)
parser.add_argument('--img-h', type=int, default=70)
parser.add_argument('--save-every', type=int, default=20)
args = parser.parse_args()
train(args)
if __name__ == '__main__':
main()