예제 #1
0
def main():
    global args
    args = parser.parse_args()
    if args.save is '':
        args.save = datetime.now().strftime('%Y-%m-%d_%H-%M-%S')
    save_path = os.path.join(args.results_dir, args.save)
    if not os.path.exists(save_path):
        os.makedirs(save_path)

    setup_logging(os.path.join(save_path, 'log.txt'))
    checkpoint_file = os.path.join(save_path, 'checkpoint_epoch_%s.pth.tar')

    logging.debug("run arguments: %s", args)
    logging.info("using pretrained cnn %s", args.cnn)
    cnn = resnet.__dict__[args.cnn](pretrained=True)

    vocab = build_vocab()
    model = CaptionModel(cnn, vocab,
                         embedding_size=args.embedding_size,
                         rnn_size=args.rnn_size,
                         num_layers=args.num_layers,
                         share_embedding_weights=args.share_weights)

    train_data = get_iterator(get_coco_data(vocab, train=True),
                              batch_size=args.batch_size,
                              max_length=args.max_length,
                              shuffle=True,
                              num_workers=args.workers)
    val_data = get_iterator(get_coco_data(vocab, train=False),
                            batch_size=args.eval_batch_size,
                            max_length=args.max_length,
                            shuffle=False,
                            num_workers=args.workers)

    if 'cuda' in args.type:
        cudnn.benchmark = True
        model.cuda()

    optimizer = select_optimizer(
        args.optimizer, params=model.parameters(), lr=args.lr)
    regime = lambda e: {'lr': args.lr * (args.lr_decay ** e),
                        'momentum': args.momentum,
                        'weight_decay': args.weight_decay}
    model.finetune_cnn(False)

    def forward(model, data, training=True, optimizer=None):
        use_cuda = 'cuda' in args.type
        loss = nn.CrossEntropyLoss()
        perplexity = AverageMeter()
        batch_time = AverageMeter()
        data_time = AverageMeter()

        if training:
            model.train()
        else:
            model.eval()

        end = time.time()
        for i, (imgs, (captions, lengths)) in enumerate(data):
            data_time.update(time.time() - end)
            if use_cuda:
                imgs = imgs.cuda()
                captions = captions.cuda(async=True)
            imgs = Variable(imgs, volatile=not training)
            captions = Variable(captions, volatile=not training)
            input_captions = captions[:-1]
            target_captions = pack_padded_sequence(captions, lengths)[0]

            pred, _ = model(imgs, input_captions, lengths)
            err = loss(pred, target_captions)
            perplexity.update(math.exp(err.data[0]))

            if training:
                optimizer.zero_grad()
                err.backward()
                clip_grad_norm(model.rnn.parameters(), args.grad_clip)
                optimizer.step()

            # measure elapsed time
            batch_time.update(time.time() - end)
            end = time.time()
            if i % args.print_freq == 0:
                logging.info('{phase} - Epoch: [{0}][{1}/{2}]\t'
                             'Time {batch_time.val:.3f} ({batch_time.avg:.3f})\t'
                             'Data {data_time.val:.3f} ({data_time.avg:.3f})\t'
                             'Perplexity {perp.val:.4f} ({perp.avg:.4f})'.format(
                                 epoch, i, len(data),
                                 phase='TRAINING' if training else 'EVALUATING',
                                 batch_time=batch_time,
                                 data_time=data_time, perp=perplexity))

        return perplexity.avg

    for epoch in range(args.start_epoch, args.epochs):
        if epoch >= args.finetune_epoch:
            model.finetune_cnn(True)
        optimizer = adjust_optimizer(
            optimizer, epoch, regime)
        # Train
        train_perp = forward(
            model, train_data, training=True, optimizer=optimizer)
        # Evaluate
        val_perp = forward(model, val_data, training=False)

        logging.info('\n Epoch: {0}\t'
                     'Training Perplexity {train_perp:.4f} \t'
                     'Validation Perplexity {val_perp:.4f} \n'
                     .format(epoch + 1, train_perp=train_perp, val_perp=val_perp))
        model.save_checkpoint(checkpoint_file % (epoch + 1))
                         num_layers=num_layers,
                         share_embedding_weights=share_weights)

    if 'cuda' in type:
        cudnn.benchmark = True
        model.cuda()

    optimizer = select_optimizer(optimizer,
                                 params=model.parameters(),
                                 lr=learning_rate)
    regime = lambda e: {
        'lr': learning_rate * (lr_decay**e),
        'momentum': momentum,
        'weight_decay': weight_decay
    }
    model.finetune_cnn(False)

    def forward(model, data, training=True, optimizer=None):
        use_cuda = 'cuda' in type
        loss = nn.CrossEntropyLoss()
        perplexity = AverageMeter()
        batch_time = AverageMeter()
        data_time = AverageMeter()

        if training:
            model.train()
        else:
            model.eval()

        end = time.time()
        for i, (imgs, (captions, lengths)) in enumerate(data):