예제 #1
0
def build_baseline_model():

    log.i('BUILDING BASELINE MODEL...')

    # Random Seed
    lasagne_random.set_rng(cfg.getRandomState())

    # Input layer for images
    net = l.InputLayer((None, cfg.IM_DIM, cfg.IM_SIZE[1], cfg.IM_SIZE[0]))

    # Stride size (as an alternative to max pooling)
    if cfg.MAX_POOLING:
        s = 1
    else:
        s = 2

    # Convolutinal layer groups
    for i in range(len(cfg.FILTERS)):

        # 3x3 Convolution + Stride
        net = batch_norm(
            l.Conv2DLayer(net,
                          num_filters=cfg.FILTERS[i],
                          filter_size=cfg.KERNEL_SIZES[i],
                          num_groups=cfg.NUM_OF_GROUPS[i],
                          pad='same',
                          stride=s,
                          W=initialization(cfg.NONLINEARITY),
                          nonlinearity=nonlinearity(cfg.NONLINEARITY)))

        # Pooling layer
        if cfg.MAX_POOLING:
            net = l.MaxPool2DLayer(net, pool_size=2)

        # Dropout Layer (we support different types of dropout)
        if cfg.DROPOUT_TYPE == 'channels' and cfg.DROPOUT > 0.0:
            net = l.dropout_channels(net, p=cfg.DROPOUT)
        elif cfg.DROPOUT_TYPE == 'location' and cfg.DROPOUT > 0.0:
            net = l.dropout_location(net, p=cfg.DROPOUT)
        elif cfg.DROPOUT > 0.0:
            net = l.DropoutLayer(net, p=cfg.DROPOUT)

        log.i(('\tGROUP', i + 1, 'OUT SHAPE:', l.get_output_shape(net)))

    # Final 1x1 Convolution
    net = batch_norm(
        l.Conv2DLayer(net,
                      num_filters=cfg.FILTERS[i] * 2,
                      filter_size=1,
                      W=initialization('identity'),
                      nonlinearity=nonlinearity('identity')))

    log.i(('\tFINAL CONV OUT SHAPE:', l.get_output_shape(net)))

    # Global Pooling layer (default mode = average)
    net = l.GlobalPoolLayer(net)
    log.i(("\tFINAL POOLING SHAPE:", l.get_output_shape(net)))

    # Classification Layer (Softmax)
    net = l.DenseLayer(net,
                       len(cfg.CLASSES),
                       nonlinearity=nonlinearity('softmax'),
                       W=initialization('softmax'))

    log.i(("\tFINAL NET OUT SHAPE:", l.get_output_shape(net)))
    log.i("...DONE!")

    # Model stats
    log.i(("MODEL HAS",
           (sum(hasattr(layer, 'W')
                for layer in l.get_all_layers(net))), "WEIGHTED LAYERS"))
    log.i(("MODEL HAS", l.count_params(net), "PARAMS"))

    return net
예제 #2
0
def resblock(net_in,
             filters,
             kernel_size,
             stride=1,
             num_groups=1,
             preactivated=True):

    # Preactivation
    net_pre = batch_norm(net_in)
    net_pre = l.NonlinearityLayer(net_pre,
                                  nonlinearity=nonlinearity(cfg.NONLINEARITY))

    # Preactivated shortcut?
    if preactivated:
        net_sc = net_pre
    else:
        net_sc = net_in

    # Stride size
    if cfg.MAX_POOLING:
        s = 1
    else:
        s = stride

    # First Convolution (alwys has preactivated input)
    net = batch_norm(
        l.Conv2DLayer(net_pre,
                      num_filters=filters,
                      filter_size=kernel_size,
                      pad='same',
                      stride=s,
                      num_groups=num_groups,
                      W=initialization(cfg.NONLINEARITY),
                      nonlinearity=nonlinearity(cfg.NONLINEARITY)))

    # Optional pooling layer
    if cfg.MAX_POOLING and stride > 1:
        net = l.MaxPool2DLayer(net, pool_size=stride)

    # Dropout Layer (we support different types of dropout)
    if cfg.DROPOUT_TYPE == 'channels' and cfg.DROPOUT > 0.0:
        net = l.dropout_channels(net, p=cfg.DROPOUT)
    elif cfg.DROPOUT_TYPE == 'location' and cfg.DROPOUT > 0.0:
        net = l.dropout_location(net, p=cfg.DROPOUT)
    elif cfg.DROPOUT > 0.0:
        net = l.DropoutLayer(net, p=cfg.DROPOUT)

    # Second Convolution
    net = l.Conv2DLayer(net,
                        num_filters=filters,
                        filter_size=kernel_size,
                        pad='same',
                        stride=1,
                        num_groups=num_groups,
                        W=initialization(cfg.NONLINEARITY),
                        nonlinearity=None)

    # Shortcut Layer
    if not l.get_output_shape(net) == l.get_output_shape(net_sc):
        shortcut = l.Conv2DLayer(net_sc,
                                 num_filters=filters,
                                 filter_size=1,
                                 pad='same',
                                 stride=s,
                                 W=initialization(cfg.NONLINEARITY),
                                 nonlinearity=None,
                                 b=None)

        # Optional pooling layer
        if cfg.MAX_POOLING and stride > 1:
            shortcut = l.MaxPool2DLayer(shortcut, pool_size=stride)
    else:
        shortcut = net_sc

    # Merge Layer
    out = l.ElemwiseSumLayer([net, shortcut])

    return out