main.py

# ------------------------------------------------------------------------
# Modified from DETR (https://github.com/facebookresearch/detr)
# and UP-DETR (https://github.com/dddzg/up-detr)
# Copyright 2021 Aman Arora
# ------------------------------------------------------------------------

import argparse
import datetime
import json
import random
import time
from pathlib import Path
from tripod.models.model_factory import build_criterion, build_postprocessors, build_model
import tripod.data as data

import numpy as np
import torch

import tripod.util.misc as utils
from tripod.data.data_factory import build_loader
from tripod.data import build_dataset, get_coco_api_from_dataset
from engine import evaluate, train_one_epoch


def get_args_parser():
    parser = argparse.ArgumentParser('Set transformer detector', add_help=False)
    parser.add_argument('--mode', default='train_eval', type=str)
    parser.add_argument('--lr', default=1e-4, type=float)
    parser.add_argument('--lr_backbone', default=1e-5, type=float)
    parser.add_argument('--batch_size', default=2, type=int)
    parser.add_argument('--weight_decay', default=1e-4, type=float)
    parser.add_argument('--epochs', default=300, type=int)
    parser.add_argument('--lr_drop', default=200, type=int)
    parser.add_argument('--clip_max_norm', default=0.1, type=float,
                        help='gradient clipping max norm')

    # Model parameters
    parser.add_argument('--frozen_weights', type=str, default=None,
                        help="Path to the pretrained model. If set, only the mask head will be trained")
    # * Backbone
    parser.add_argument('--backbone', default='resnet50', type=str,
                        help="Name of the convolutional backbone to use")
    parser.add_argument('--dilation', action='store_true',
                        help="If true, we replace stride with dilation in the last convolutional block (DC5)")
    parser.add_argument('--position_embedding', default='sine', type=str, choices=('sine', 'learned'),
                        help="Type of positional embedding to use on top of the image features")

    # * Transformer
    parser.add_argument('--enc_layers', default=6, type=int,
                        help="Number of encoding layers in the transformer")
    parser.add_argument('--dec_layers', default=6, type=int,
                        help="Number of decoding layers in the transformer")
    parser.add_argument('--dim_feedforward', default=2048, type=int,
                        help="Intermediate size of the feedforward layers in the transformer blocks")
    parser.add_argument('--hidden_dim', default=256, type=int,
                        help="Size of the embeddings (dimension of the transformer)")
    parser.add_argument('--dropout', default=0.1, type=float,
                        help="Dropout applied in the transformer")
    parser.add_argument('--nheads', default=8, type=int,
                        help="Number of attention heads inside the transformer's attentions")
    parser.add_argument('--num_queries', default=100, type=int,
                        help="Number of query slots")
    parser.add_argument('--pre_norm', action='store_true')

    # * Segmentation
    parser.add_argument('--masks', action='store_true',
                        help="Train segmentation head if the flag is provided")

    # Loss
    parser.add_argument('--no_aux_loss', dest='aux_loss', action='store_false',
                        help="Disables auxiliary decoding losses (loss at each layer)")
    # * Matcher
    parser.add_argument('--set_cost_class', default=1, type=float,
                        help="Class coefficient in the matching cost")
    parser.add_argument('--set_cost_bbox', default=5, type=float,
                        help="L1 box coefficient in the matching cost")
    parser.add_argument('--set_cost_giou', default=2, type=float,
                        help="giou box coefficient in the matching cost")
    # * Loss coefficients
    parser.add_argument('--mask_loss_coef', default=1, type=float)
    parser.add_argument('--dice_loss_coef', default=1, type=float)
    parser.add_argument('--bbox_loss_coef', default=5, type=float)
    parser.add_argument('--giou_loss_coef', default=2, type=float)
    parser.add_argument('--eos_coef', default=0.1, type=float,
                        help="Relative classification weight of the no-object class")

    # dataset parameters
    parser.add_argument('--dataset_file', default='coco')
    parser.add_argument('--coco_path', type=str)
    parser.add_argument('--coco_panoptic_path', type=str)
    parser.add_argument('--remove_difficult', action='store_true')

    parser.add_argument('--output_dir', default='',
                        help='path where to save, empty for no saving')
    parser.add_argument('--device', default='cuda',
                        help='device to use for training / testing')
    parser.add_argument('--seed', default=42, type=int)
    parser.add_argument('--resume', default='', help='resume from checkpoint')
    parser.add_argument('--start_epoch', default=0, type=int, metavar='N',
                        help='start epoch')
    parser.add_argument('--eval', action='store_true')
    parser.add_argument('--num_workers', default=2, type=int)

    # distributed training parameters
    parser.add_argument('--world_size', default=1, type=int,
                        help='number of distributed processes')
    parser.add_argument('--dist_url', default='env://', help='url used to set up distributed training')
    parser.add_argument('--initial-checkpoint', default='', type=str, metavar='PATH',
                    help='Initialize model from this checkpoint (default: none)')

    # UP-DETR pretraining 
    parser.add_argument('--num_patches', default=10, type=int, help='number of query patches')
    parser.add_argument('--imagenet_path', type=str, default="", help="path to the ImageNet dataset, like ImageNet")
    parser.add_argument('--feature_recon', action='store_true', help='if set, add feature reconstruction branch')
    parser.add_argument('--query_shuffle', action='store_true', help='if set, shuffle object queries')
    parser.add_argument('--freeze_cnn', action='store_true', help="if set, freeze cnn parameters during the pre-training")

    return parser


def main(args):
    utils.init_distributed_mode(args)
    print("git:\n  {}\n".format(utils.get_sha()))

    if args.frozen_weights is not None:
        assert args.masks, "Frozen training is meant for segmentation only"
    
    if args.imagenet_path:
        args.lr_backbone = 0 if args.freeze_cnn else args.lr # freeze cnn weights
        args.dataset_file = 'ImageNet'
        args.mode = 'pretrain'
        assert not args.masks, "We only pretrain for instance detection using UP-DETR method"

    print(args)

    device = torch.device(args.device)

    # fix the seed for reproducibility
    seed = args.seed + utils.get_rank()
    torch.manual_seed(seed)
    np.random.seed(seed)
    random.seed(seed)

    # build model
    model = build_model(args)
    model.to(device)

    # build criterion
    criterion = build_criterion(args)
    
    # build postprocessors
    postprocessors = build_postprocessors(args)

    model_without_ddp = model
    if args.distributed:
        model = torch.nn.parallel.DistributedDataParallel(model, device_ids=[args.gpu])
        model_without_ddp = model.module
    n_parameters = sum(p.numel() for p in model.parameters() if p.requires_grad)
    print('number of params:', n_parameters)

    param_dicts = [
        {"params": [p for n, p in model_without_ddp.named_parameters() if "backbone" not in n and p.requires_grad]},
        {
            "params": [p for n, p in model_without_ddp.named_parameters() if "backbone" in n and p.requires_grad],
            "lr": args.lr_backbone,
        },
    ]
    optimizer = torch.optim.AdamW(param_dicts, lr=args.lr,
                                  weight_decay=args.weight_decay)
    lr_scheduler = torch.optim.lr_scheduler.StepLR(optimizer, args.lr_drop)

    dataset_train = build_dataset(image_set='train', args=args)
    data_loader_train = build_loader(dataset_train, 
        is_training=True, 
        is_distributed=args.distributed, 
        shuffle=True, 
        batch_size=args.batch_size,
        drop_last=True,
        use_updetr_collate=args.mode=='pretrain',
        num_workers=args.num_workers)
    
    # we don't need to do validation when pretraining 
    if not args.mode=='pretrain':
        dataset_val = build_dataset(image_set='val', args=args)
        data_loader_val = build_loader(dataset_val, 
            is_training=False, 
            is_distributed=args.distributed, 
            shuffle=False, 
            batch_size=args.batch_size,
            drop_last=False,
            use_updetr_collate=args.mode=='pretrain',
            num_workers=args.num_workers)

    if args.frozen_weights is not None:
        checkpoint = torch.load(args.frozen_weights, map_location='cpu')
        model_without_ddp.detr.load_state_dict(checkpoint['model'])

    output_dir = Path(args.output_dir)

    if args.initial_checkpoint:
        print('Initialized from the pre-training model')
        checkpoint = torch.load(args.initial_checkpoint, map_location='cpu')
        state_dict = checkpoint['model']

        # remove class embed
        for k in list(state_dict.keys()):
            if 'class_embed' in k:
                del state_dict[k]

        msg = model_without_ddp.load_state_dict(state_dict, strict=False)
        print(msg)

    if args.resume:
        if args.resume.startswith('https'):
            checkpoint = torch.hub.load_state_dict_from_url(
                args.resume, map_location='cpu', check_hash=True)
        else:
            checkpoint = torch.load(args.resume, map_location='cpu')
        model_without_ddp.load_state_dict(checkpoint['model'])
        if not args.eval and 'optimizer' in checkpoint and 'lr_scheduler' in checkpoint and 'epoch' in checkpoint:
            optimizer.load_state_dict(checkpoint['optimizer'])
            lr_scheduler.load_state_dict(checkpoint['lr_scheduler'])
            args.start_epoch = checkpoint['epoch'] + 1

    if not args.mode=='pretrain':
        if args.dataset_file == "coco_panoptic":
            # We also evaluate AP during panoptic training, on original coco DS
            coco_val = data.coco.build("val", args)
            base_ds = get_coco_api_from_dataset(coco_val)
        else:
            base_ds = get_coco_api_from_dataset(dataset_val)

    if args.eval and not args.mode=='pretrain':        
        test_stats, coco_evaluator = evaluate(model, criterion, postprocessors,
                                              data_loader_val, base_ds, device, args.output_dir)
        if args.output_dir:
            utils.save_on_master(coco_evaluator.coco_eval["bbox"].eval, output_dir / "eval.pth")
        return

    print("Start training")
    start_time = time.time()
    for epoch in range(args.start_epoch, args.epochs):
        if args.distributed and hasattr(data_loader_train.sampler, 'set_epoch'):
            data_loader_train.sampler.set_epoch(epoch)
        train_stats = train_one_epoch(
            model, criterion, data_loader_train, optimizer, device, epoch,
            args.clip_max_norm)
        lr_scheduler.step()
        if args.output_dir:
            checkpoint_paths = [output_dir / 'checkpoint.pth']
            # extra checkpoint before LR drop and every 100 epochs
            if (epoch + 1) % args.lr_drop == 0 or (epoch + 1) % 100 == 0:
                checkpoint_paths.append(output_dir / f'checkpoint{epoch:04}.pth')
            for checkpoint_path in checkpoint_paths:
                utils.save_on_master({
                    'model': model_without_ddp.state_dict(),
                    'optimizer': optimizer.state_dict(),
                    'lr_scheduler': lr_scheduler.state_dict(),
                    'epoch': epoch,
                    'args': args,
                }, checkpoint_path)

        log_stats = {**{f'train_{k}': v for k, v in train_stats.items()},
                     'epoch': epoch,
                     'n_parameters': n_parameters}

        coco_evaluator=None
        if not args.mode=='pretrain':
            test_stats, coco_evaluator = evaluate(
                model, criterion, postprocessors, data_loader_val, base_ds, device, args.output_dir
            )
            log_stats.update(**{f'test_{k}': v for k, v in test_stats.items()})
        
        if args.output_dir and utils.is_main_process():
            with (output_dir / "log.txt").open("a") as f:
                f.write(json.dumps(log_stats) + "\n")

            # for evaluation logs
            if coco_evaluator is not None:
                (output_dir / 'eval').mkdir(exist_ok=True)
                if "bbox" in coco_evaluator.coco_eval:
                    filenames = ['latest.pth']
                    if epoch % 50 == 0:
                        filenames.append(f'{epoch:03}.pth')
                    for name in filenames:
                        torch.save(coco_evaluator.coco_eval["bbox"].eval,
                                   output_dir / "eval" / name)

    total_time = time.time() - start_time
    total_time_str = str(datetime.timedelta(seconds=int(total_time)))
    print('Training time {}'.format(total_time_str))


if __name__ == '__main__':
    parser = argparse.ArgumentParser('DETR training and evaluation script', parents=[get_args_parser()])
    args = parser.parse_args()
    if args.output_dir:
        Path(args.output_dir).mkdir(parents=True, exist_ok=True)
    main(args)