from __future__ import print_function, division import sys sys.path.append('core') import argparse import os import cv2 import time import numpy as np import matplotlib.pyplot as plt import torch import torch.nn as nn import torch.optim as optim import torch.nn.functional as F from torch.utils.data import DataLoader from raft import RAFT import evaluate import datasets from torch.utils.tensorboard import SummaryWriter try: from torch.cuda.amp import GradScaler except: # dummy GradScaler for PyTorch < 1.6 class GradScaler: def __init__(self): pass def scale(self, loss): return loss def unscale_(self, optimizer): pass def step(self, optimizer): optimizer.step() def update(self): pass # exclude extremly large displacements MAX_FLOW = 400 SUM_FREQ = 100 VAL_FREQ = 5000 def sequence_loss(flow_preds, flow_gt, valid, gamma=0.8, max_flow=MAX_FLOW): """ Loss function defined over sequence of flow predictions """ n_predictions = len(flow_preds) flow_loss = 0.0 # exlude invalid pixels and extremely large diplacements mag = torch.sum(flow_gt**2, dim=1).sqrt() valid = (valid >= 0.5) & (mag < max_flow) for i in range(n_predictions): i_weight = gamma**(n_predictions - i - 1) i_loss = (flow_preds[i] - flow_gt).abs() flow_loss += i_weight * (valid[:, None] * i_loss).mean() epe = torch.sum((flow_preds[-1] - flow_gt)**2, dim=1).sqrt() epe = epe.view(-1)[valid.view(-1)] metrics = { 'epe': epe.mean().item(), '1px': (epe < 1).float().mean().item(), '3px': (epe < 3).float().mean().item(), '5px': (epe < 5).float().mean().item(), } return flow_loss, metrics def count_parameters(model): return sum(p.numel() for p in model.parameters() if p.requires_grad) def fetch_optimizer(args, model): """ Create the optimizer and learning rate scheduler """ optimizer = optim.AdamW(model.parameters(), lr=args.lr, weight_decay=args.wdecay, eps=args.epsilon) scheduler = optim.lr_scheduler.OneCycleLR(optimizer, args.lr, args.num_steps+100, pct_start=0.05, cycle_momentum=False, anneal_strategy='linear') return optimizer, scheduler class Logger: def __init__(self, model, scheduler): self.model = model self.scheduler = scheduler self.total_steps = 0 self.running_loss = {} self.writer = None def _print_training_status(self): metrics_data = [self.running_loss[k]/SUM_FREQ for k in sorted(self.running_loss.keys())] training_str = "[{:6d}, {:10.7f}] ".format(self.total_steps+1, self.scheduler.get_last_lr()[0]) metrics_str = ("{:10.4f}, "*len(metrics_data)).format(*metrics_data) # print the training status print(training_str + metrics_str) if self.writer is None: self.writer = SummaryWriter() for k in self.running_loss: self.writer.add_scalar(k, self.running_loss[k]/SUM_FREQ, self.total_steps) self.running_loss[k] = 0.0 def push(self, metrics): self.total_steps += 1 for key in metrics: if key not in self.running_loss: self.running_loss[key] = 0.0 self.running_loss[key] += metrics[key] if self.total_steps % SUM_FREQ == SUM_FREQ-1: self._print_training_status() self.running_loss = {} def write_dict(self, results): if self.writer is None: self.writer = SummaryWriter() for key in results: self.writer.add_scalar(key, results[key], self.total_steps) def close(self): self.writer.close() def train(args): model = nn.DataParallel(RAFT(args), device_ids=args.gpus) print("Parameter Count: %d" % count_parameters(model)) if args.restore_ckpt is not None: model.load_state_dict(torch.load(args.restore_ckpt), strict=False) model.cuda() model.train() if args.stage != 'chairs': model.module.freeze_bn() train_loader = datasets.fetch_dataloader(args) optimizer, scheduler = fetch_optimizer(args, model) total_steps = 0 scaler = GradScaler(enabled=args.mixed_precision) logger = Logger(model, scheduler) VAL_FREQ = 5000 add_noise = True should_keep_training = True while should_keep_training: for i_batch, data_blob in enumerate(train_loader): optimizer.zero_grad() image1, image2, flow, valid = [x.cuda() for x in data_blob] if args.add_noise: stdv = np.random.uniform(0.0, 5.0) image1 = (image1 + stdv * torch.randn(*image1.shape).cuda()).clamp(0.0, 255.0) image2 = (image2 + stdv * torch.randn(*image2.shape).cuda()).clamp(0.0, 255.0) flow_predictions = model(image1, image2, iters=args.iters) loss, metrics = sequence_loss(flow_predictions, flow, valid, args.gamma) scaler.scale(loss).backward() scaler.unscale_(optimizer) torch.nn.utils.clip_grad_norm_(model.parameters(), args.clip) scaler.step(optimizer) scheduler.step() scaler.update() logger.push(metrics) if total_steps % VAL_FREQ == VAL_FREQ - 1: PATH = 'checkpoints/%d_%s.pth' % (total_steps+1, args.name) torch.save(model.state_dict(), PATH) results = {} for val_dataset in args.validation: if val_dataset == 'chairs': results.update(evaluate.validate_chairs(model.module)) elif val_dataset == 'sintel': results.update(evaluate.validate_sintel(model.module)) elif val_dataset == 'kitti': results.update(evaluate.validate_kitti(model.module)) logger.write_dict(results) model.train() if args.stage != 'chairs': model.module.freeze_bn() total_steps += 1 if total_steps > args.num_steps: should_keep_training = False break logger.close() PATH = 'checkpoints/%s.pth' % args.name torch.save(model.state_dict(), PATH) return PATH if __name__ == '__main__': parser = argparse.ArgumentParser() parser.add_argument('--name', default='raft', help="name your experiment") parser.add_argument('--stage', help="determines which dataset to use for training") parser.add_argument('--restore_ckpt', help="restore checkpoint") parser.add_argument('--small', action='store_true', help='use small model') parser.add_argument('--validation', type=str, nargs='+') parser.add_argument('--lr', type=float, default=0.00002) parser.add_argument('--num_steps', type=int, default=100000) parser.add_argument('--batch_size', type=int, default=6) parser.add_argument('--image_size', type=int, nargs='+', default=[384, 512]) parser.add_argument('--gpus', type=int, nargs='+', default=[0,1]) parser.add_argument('--mixed_precision', action='store_true', help='use mixed precision') parser.add_argument('--iters', type=int, default=12) parser.add_argument('--wdecay', type=float, default=.00005) parser.add_argument('--epsilon', type=float, default=1e-8) parser.add_argument('--clip', type=float, default=1.0) parser.add_argument('--dropout', type=float, default=0.0) parser.add_argument('--gamma', type=float, default=0.8, help='exponential weighting') parser.add_argument('--add_noise', action='store_true') args = parser.parse_args() torch.manual_seed(1234) np.random.seed(1234) if not os.path.isdir('checkpoints'): os.mkdir('checkpoints') train(args)