Python keras.backend.is_keras_tensor() Examples

def test_jaccard_distance():
    # all_right, almost_right, half_right, all_wrong
    y_true = np.array([[0, 0, 1, 0], [0, 0, 1, 0], [0, 0, 1, 0],
                       [0, 0, 1., 0.]])
    y_pred = np.array([[0, 0, 1, 0], [0, 0, 0.9, 0], [0, 0, 0.1, 0],
                       [1, 1, 0.1, 1.]])

    r = jaccard_distance(
        K.variable(y_true),
        K.variable(y_pred), )
    if K.is_keras_tensor(r):
        assert K.int_shape(r) == (4, )

    all_right, almost_right, half_right, all_wrong = K.eval(r)
    assert all_right == 0, 'should converge on zero'
    assert all_right < almost_right
    assert almost_right < half_right
    assert half_right < all_wrong 

def fmeasure(y_true, y_pred):
    try:
        _ = K.is_keras_tensor(y_pred)
        return fbeta_score_K(y_true, y_pred, beta=1)
    except ValueError:
        return fbeta_score_np(y_true, y_pred, beta=1) 

def __init__(
        self,
        num_classes,
        input_tensor=None,
        input_shape=None,
        initial_block_filters=64,
        bias=False,
        name='linknet'
    ):
        self.num_classes = num_classes
        self.initial_block_filters = initial_block_filters
        self.bias = bias
        self.output_shape = input_shape[:-1] + (num_classes, )

        # Create a Keras tensor from the input_shape/input_tensor
        if input_tensor is None:
            self.input = Input(shape=input_shape, name='input_img')
        elif is_keras_tensor(input_tensor):
            self.input = input_tensor
        else:
            # input_tensor is a tensor but not one from Keras
            self.input = Input(
                tensor=input_tensor, shape=input_shape, name='input_img'
            )

        self.name = name 

def __call__(self, inputs, initial_state=None, **kwargs):
        # We skip `__call__` of `RNN` and `GRU` in this case and directly execute
        # GRUD's great-grandparent's method.
        inputs, initial_state = _standardize_grud_args(inputs, initial_state)

        if initial_state is None:
            return super(RNN, self).__call__(inputs, **kwargs)

        # If `initial_state` is specified and is Keras
        # tensors, then add it to the inputs and temporarily modify the
        # input_spec to include them.

        additional_inputs = []
        additional_specs = []
        kwargs['initial_state'] = initial_state
        additional_inputs += initial_state
        self.state_spec = [InputSpec(shape=K.int_shape(state))
                           for state in initial_state]
        additional_specs += self.state_spec
        # at this point additional_inputs cannot be empty
        is_keras_tensor = K.is_keras_tensor(additional_inputs[0])
        for tensor in additional_inputs:
            if K.is_keras_tensor(tensor) != is_keras_tensor:
                raise ValueError('The initial state or constants of an RNN'
                                 ' layer cannot be specified with a mix of'
                                 ' Keras tensors and non-Keras tensors'
                                 ' (a "Keras tensor" is a tensor that was'
                                 ' returned by a Keras layer, or by `Input`)')

        if is_keras_tensor:
            # Compute the full input spec, including state and constants
            full_input = inputs + additional_inputs
            full_input_spec = self.input_spec + additional_specs
            # Perform the call with temporarily replaced input_spec
            original_input_spec = self.input_spec
            self.input_spec = full_input_spec
            output = super(RNN, self).__call__(full_input, **kwargs)
            self.input_spec = original_input_spec
            return output
        return super(RNN, self).__call__(inputs, **kwargs) 

def nn_base(input_tensor=None, trainable=False):
    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable=trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable=trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable=trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable=trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable=trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable=trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable=trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable=trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='g', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='h', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='i', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='j', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='k', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='l', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='m', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='n', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='o', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='p', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='q', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='r', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='s', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='t', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='u', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='v', trainable=trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='w', trainable=trainable)

    return x 

def nn_base(input_tensor=None, trainable=False):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x 

def get_dilation_model_camvid(input_shape, apply_softmax, input_tensor, classes):

    if input_tensor is None:
        model_in = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            model_in = Input(tensor=input_tensor, shape=input_shape)
        else:
            model_in = input_tensor

    h = Convolution2D(64, 3, 3, activation='relu', name='conv1_1')(model_in)
    h = Convolution2D(64, 3, 3, activation='relu', name='conv1_2')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool1')(h)
    h = Convolution2D(128, 3, 3, activation='relu', name='conv2_1')(h)
    h = Convolution2D(128, 3, 3, activation='relu', name='conv2_2')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool2')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_1')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_2')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_3')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool3')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_1')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_2')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_3')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_1')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_2')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_3')(h)
    h = AtrousConvolution2D(4096, 7, 7, atrous_rate=(4, 4), activation='relu', name='fc6')(h)
    h = Dropout(0.5, name='drop6')(h)
    h = Convolution2D(4096, 1, 1, activation='relu', name='fc7')(h)
    h = Dropout(0.5, name='drop7')(h)
    h = Convolution2D(classes, 1, 1, name='final')(h)
    h = ZeroPadding2D(padding=(1, 1))(h)
    h = Convolution2D(classes, 3, 3, activation='relu', name='ctx_conv1_1')(h)
    h = ZeroPadding2D(padding=(1, 1))(h)
    h = Convolution2D(classes, 3, 3, activation='relu', name='ctx_conv1_2')(h)
    h = ZeroPadding2D(padding=(2, 2))(h)
    h = AtrousConvolution2D(classes, 3, 3, atrous_rate=(2, 2), activation='relu', name='ctx_conv2_1')(h)
    h = ZeroPadding2D(padding=(4, 4))(h)
    h = AtrousConvolution2D(classes, 3, 3, atrous_rate=(4, 4), activation='relu', name='ctx_conv3_1')(h)
    h = ZeroPadding2D(padding=(8, 8))(h)
    h = AtrousConvolution2D(classes, 3, 3, atrous_rate=(8, 8), activation='relu', name='ctx_conv4_1')(h)
    h = ZeroPadding2D(padding=(16, 16))(h)
    h = AtrousConvolution2D(classes, 3, 3, atrous_rate=(16, 16), activation='relu', name='ctx_conv5_1')(h)
    h = ZeroPadding2D(padding=(1, 1))(h)
    h = Convolution2D(classes, 3, 3, activation='relu', name='ctx_fc1')(h)
    logits = Convolution2D(classes, 1, 1, name='ctx_final')(h)

    if apply_softmax:
        model_out = softmax(logits)
    else:
        model_out = logits

    model = Model(input=model_in, output=model_out, name='dilation_camvid')

    return model


# model function 

def get_dilation_model_kitti(input_shape, apply_softmax, input_tensor, classes):

    if input_tensor is None:
        model_in = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            model_in = Input(tensor=input_tensor, shape=input_shape)
        else:
            model_in = input_tensor

    h = Convolution2D(64, 3, 3, activation='relu', name='conv1_1')(model_in)
    h = Convolution2D(64, 3, 3, activation='relu', name='conv1_2')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool1')(h)
    h = Convolution2D(128, 3, 3, activation='relu', name='conv2_1')(h)
    h = Convolution2D(128, 3, 3, activation='relu', name='conv2_2')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool2')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_1')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_2')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_3')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool3')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_1')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_2')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_3')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_1')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_2')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_3')(h)
    h = AtrousConvolution2D(4096, 7, 7, atrous_rate=(4, 4), activation='relu', name='fc6')(h)
    h = Dropout(0.5, name='drop6')(h)
    h = Convolution2D(4096, 1, 1, activation='relu', name='fc7')(h)
    h = Dropout(0.5, name='drop7')(h)
    h = Convolution2D(classes, 1, 1, name='final')(h)
    h = ZeroPadding2D(padding=(1, 1))(h)
    h = Convolution2D(classes, 3, 3, activation='relu', name='ctx_conv1_1')(h)
    h = ZeroPadding2D(padding=(1, 1))(h)
    h = Convolution2D(classes, 3, 3, activation='relu', name='ctx_conv1_2')(h)
    h = ZeroPadding2D(padding=(2, 2))(h)
    h = AtrousConvolution2D(classes, 3, 3, atrous_rate=(2, 2), activation='relu', name='ctx_conv2_1')(h)
    h = ZeroPadding2D(padding=(4, 4))(h)
    h = AtrousConvolution2D(classes, 3, 3, atrous_rate=(4, 4), activation='relu', name='ctx_conv3_1')(h)
    h = ZeroPadding2D(padding=(8, 8))(h)
    h = AtrousConvolution2D(classes, 3, 3, atrous_rate=(8, 8), activation='relu', name='ctx_conv4_1')(h)
    h = ZeroPadding2D(padding=(1, 1))(h)
    h = Convolution2D(classes, 3, 3, activation='relu', name='ctx_fc1')(h)
    logits = Convolution2D(classes, 1, 1, name='ctx_final')(h)

    if apply_softmax:
        model_out = softmax(logits)
    else:
        model_out = logits

    model = Model(input=model_in, output=model_out, name='dilation_kitti')

    return model


# CAMVID MODEL 

def get_dilation_model_voc(input_shape, apply_softmax, input_tensor, classes):

    if input_tensor is None:
        model_in = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            model_in = Input(tensor=input_tensor, shape=input_shape)
        else:
            model_in = input_tensor

    h = Convolution2D(64, 3, 3, activation='relu', name='conv1_1')(model_in)
    h = Convolution2D(64, 3, 3, activation='relu', name='conv1_2')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool1')(h)
    h = Convolution2D(128, 3, 3, activation='relu', name='conv2_1')(h)
    h = Convolution2D(128, 3, 3, activation='relu', name='conv2_2')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool2')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_1')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_2')(h)
    h = Convolution2D(256, 3, 3, activation='relu', name='conv3_3')(h)
    h = MaxPooling2D(pool_size=(2, 2), strides=(2, 2), name='pool3')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_1')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_2')(h)
    h = Convolution2D(512, 3, 3, activation='relu', name='conv4_3')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_1')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_2')(h)
    h = AtrousConvolution2D(512, 3, 3, atrous_rate=(2, 2), activation='relu', name='conv5_3')(h)
    h = AtrousConvolution2D(4096, 7, 7, atrous_rate=(4, 4), activation='relu', name='fc6')(h)
    h = Dropout(0.5, name='drop6')(h)
    h = Convolution2D(4096, 1, 1, activation='relu', name='fc7')(h)
    h = Dropout(0.5, name='drop7')(h)
    h = Convolution2D(classes, 1, 1, activation='relu', name='fc-final')(h)
    h = ZeroPadding2D(padding=(33, 33))(h)
    h = Convolution2D(2 * classes, 3, 3, activation='relu', name='ct_conv1_1')(h)
    h = Convolution2D(2 * classes, 3, 3, activation='relu', name='ct_conv1_2')(h)
    h = AtrousConvolution2D(4 * classes, 3, 3, atrous_rate=(2, 2), activation='relu', name='ct_conv2_1')(h)
    h = AtrousConvolution2D(8 * classes, 3, 3, atrous_rate=(4, 4), activation='relu', name='ct_conv3_1')(h)
    h = AtrousConvolution2D(16 * classes, 3, 3, atrous_rate=(8, 8), activation='relu', name='ct_conv4_1')(h)
    h = AtrousConvolution2D(32 * classes, 3, 3, atrous_rate=(16, 16), activation='relu', name='ct_conv5_1')(h)
    h = Convolution2D(32 * classes, 3, 3, activation='relu', name='ct_fc1')(h)
    logits = Convolution2D(classes, 1, 1, name='ct_final')(h)

    if apply_softmax:
        model_out = softmax(logits)
    else:
        model_out = logits

    model = Model(input=model_in, output=model_out, name='dilation_voc12')

    return model


# KITTI MODEL 

def nn_base(input_tensor=None, trainable=False):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x 

def nn_base(input_tensor=None, trainable=False):


    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    # Block 1
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv1')(img_input)
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv1')(x)
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv1')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv2')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv3')(x)
    # x = MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    return x 

def nn_base(input_tensor=None, trainable = False):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, 7, 7, subsample=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(trainable=False,axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x 

def densenet_cifar10_model(logits=False, input_range_type=1, pre_filter=lambda x:x):
    assert input_range_type == 1

    batch_size = 64
    nb_classes = 10

    img_rows, img_cols = 32, 32
    img_channels = 3

    img_dim = (img_channels, img_rows, img_cols) if K.image_dim_ordering() == "th" else (img_rows, img_cols, img_channels)
    depth = 40
    nb_dense_block = 3
    growth_rate = 12
    nb_filter = 16
    dropout_rate = 0.0 # 0.0 for data augmentation
    input_tensor = None
    include_top=True

    if logits is True:
        activation = None
    else:
        activation = "softmax"

    # Determine proper input shape
    input_shape = _obtain_input_shape(img_dim,
                                      default_size=32,
                                      min_size=8,
                                      data_format=K.image_data_format(),
                                      include_top=include_top)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    x = __create_dense_net(nb_classes, img_input, True, depth, nb_dense_block,
                           growth_rate, nb_filter, -1, False, 0.0,
                           dropout_rate, 1E-4, activation)

    # Ensure that the model takes into account
    # any potential predecessors of `input_tensor`.
    if input_tensor is not None:
        inputs = get_source_inputs(input_tensor)
    else:
        inputs = img_input
    # Create model.
    model = Model(inputs, x, name='densenet')
    return model


# Source: https://github.com/titu1994/DenseNet 

def nn_base(input_tensor=None, trainable=False):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x 

def nn_base(input_tensor=None, trainable=False):


    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    # Block 1
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv1')(img_input)
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv1')(x)
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv1')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv2')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv3')(x)
    # x = MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    return x 

def __call__(self, inputs, initial_state=None, constants=None, **kwargs):
        inputs, initial_state, constants = self._standardize_args(
            inputs, initial_state, constants, self._num_constants)

        if initial_state is None and constants is None:
            return super(ExternalAttentionRNNWrapper, self).__call__(inputs, **kwargs)

        # If any of `initial_state` or `constants` are specified and are Keras
        # tensors, then add them to the inputs and temporarily modify the
        # input_spec to include them.

        additional_inputs = []
        additional_specs = []
        if initial_state is not None:
            kwargs['initial_state'] = initial_state
            additional_inputs += initial_state
            self.state_spec = [InputSpec(shape=K.int_shape(state))
                               for state in initial_state]
            additional_specs += self.state_spec
        if constants is not None:
            kwargs['constants'] = constants
            additional_inputs += constants
            self.constants_spec = [InputSpec(shape=K.int_shape(constant))
                                   for constant in constants]
            self._num_constants = len(constants)
            additional_specs += self.constants_spec
        # at this point additional_inputs cannot be empty
        is_keras_tensor = K.is_keras_tensor(additional_inputs[0])
        for tensor in additional_inputs:
            if K.is_keras_tensor(tensor) != is_keras_tensor:
                raise ValueError('The initial state or constants of an ExternalAttentionRNNWrapper'
                                 ' layer cannot be specified with a mix of'
                                 ' Keras tensors and non-Keras tensors'
                                 ' (a "Keras tensor" is a tensor that was'
                                 ' returned by a Keras layer, or by `Input`)')

        if is_keras_tensor:
            # Compute the full input spec, including state and constants
            full_input = inputs + additional_inputs
            full_input_spec = self.input_spec + additional_specs
            # Perform the call with temporarily replaced input_spec
            original_input_spec = self.input_spec
            self.input_spec = full_input_spec
            output = super(ExternalAttentionRNNWrapper, self).__call__(full_input, **kwargs)
            self.input_spec = self.input_spec[:len(original_input_spec)]
            return output
        else:
            return super(ExternalAttentionRNNWrapper, self).__call__(inputs, **kwargs) 

def dcn_vgg(input_tensor=None):
    input_shape = (3, None, None)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    # conv_1
    x = Convolution2D(64, 3, 3, activation='relu', border_mode='same', name='block1_conv1')(img_input)
    x = Convolution2D(64, 3, 3, activation='relu', border_mode='same', name='block1_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # conv_2
    x = Convolution2D(128, 3, 3, activation='relu', border_mode='same', name='block2_conv1')(x)
    x = Convolution2D(128, 3, 3, activation='relu', border_mode='same', name='block2_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # conv_3
    x = Convolution2D(256, 3, 3, activation='relu', border_mode='same', name='block3_conv1')(x)
    x = Convolution2D(256, 3, 3, activation='relu', border_mode='same', name='block3_conv2')(x)
    x = Convolution2D(256, 3, 3, activation='relu', border_mode='same', name='block3_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool', border_mode='same')(x)

    # conv_4
    x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block4_conv1')(x)
    x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block4_conv2')(x)
    x = Convolution2D(512, 3, 3, activation='relu', border_mode='same', name='block4_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(1, 1), name='block4_pool', border_mode='same')(x)

    # conv_5
    x = AtrousConvolution2D(512, 3, 3, activation='relu', border_mode='same', name='block5_conv1', atrous_rate=(2, 2))(x)
    x = AtrousConvolution2D(512, 3, 3, activation='relu', border_mode='same', name='block5_conv2', atrous_rate=(2, 2))(x)
    x = AtrousConvolution2D(512, 3, 3, activation='relu', border_mode='same', name='block5_conv3', atrous_rate=(2, 2))(x)

    # Create model
    model = Model(img_input, x)

    # Load weights
    weights_path = get_file('vgg16_weights_th_dim_ordering_th_kernels_notop.h5', TH_WEIGHTS_PATH_NO_TOP,
                            cache_subdir='models')
    model.load_weights(weights_path)

    return model 

def dcn_resnet(input_tensor=None):
    input_shape = (3, None, None)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor)
        else:
            img_input = input_tensor

    bn_axis = 1

    # conv_1
    x = ZeroPadding2D((3, 3))(img_input)
    x = Convolution2D(64, 7, 7, subsample=(2, 2), name='conv1')(x)
    x = BatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2), border_mode='same')(x)

    # conv_2
    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1))
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b')
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c')

    # conv_3
    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', strides=(2, 2))
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b')
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c')
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d')

    # conv_4
    x = conv_block_atrous(x, 3, [256, 256, 1024], stage=4, block='a', atrous_rate=(2, 2))
    x = identity_block_atrous(x, 3, [256, 256, 1024], stage=4, block='b', atrous_rate=(2, 2))
    x = identity_block_atrous(x, 3, [256, 256, 1024], stage=4, block='c', atrous_rate=(2, 2))
    x = identity_block_atrous(x, 3, [256, 256, 1024], stage=4, block='d', atrous_rate=(2, 2))
    x = identity_block_atrous(x, 3, [256, 256, 1024], stage=4, block='e', atrous_rate=(2, 2))
    x = identity_block_atrous(x, 3, [256, 256, 1024], stage=4, block='f', atrous_rate=(2, 2))

    # conv_5
    x = conv_block_atrous(x, 3, [512, 512, 2048], stage=5, block='a', atrous_rate=(4, 4))
    x = identity_block_atrous(x, 3, [512, 512, 2048], stage=5, block='b', atrous_rate=(4, 4))
    x = identity_block_atrous(x, 3, [512, 512, 2048], stage=5, block='c', atrous_rate=(4, 4))

    # Create model
    model = Model(img_input, x)

    # Load weights
    weights_path = get_file('resnet50_weights_th_dim_ordering_th_kernels_notop.h5', TH_WEIGHTS_PATH_NO_TOP,
                            cache_subdir='models', md5_hash='f64f049c92468c9affcd44b0976cdafe')
    model.load_weights(weights_path)

    return model 

def nn_base(input_tensor=None, trainable=True):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x 

def nn_base(input_tensor=None,trainable=True):
    """ The architecture of VGG-16 (fixed feature extractor)
    
    Takes input_tensor as optional argument
    # do not change the arguments of the function
    
    NOTE: Make sure to give names for all the layers. These names will be
          used to freeze the corresponding layers if doing 4-step alternating training
            
    """
    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    # Block 1
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv1',trainable=trainable)(img_input)
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv2',trainable=trainable)(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool',trainable=trainable)(x) # max pooling has no trainbale layers

    # Block 2
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv1',trainable=trainable)(x)
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv2',trainable=trainable)(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool',trainable=trainable)(x)

    # Block 3
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv1',trainable=trainable)(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv2',trainable=trainable)(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv3',trainable=trainable)(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool',trainable=trainable)(x)

    # Block 4
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv1',trainable=trainable)(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv2',trainable=trainable)(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv3',trainable=trainable)(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool',trainable=trainable)(x)

    # Block 5
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv1',trainable=trainable)(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv2',trainable=trainable)(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv3',trainable=trainable)(x)
    
    return(x) 

def nn_base(input_tensor=None, trainable=False):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x 

def nn_base(input_tensor=None, trainable=False):


    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    # Block 1
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv1')(img_input)
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv1')(x)
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv1')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv2')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv3')(x)
    # x = MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    return x 

def nn_base(input_tensor=None, trainable=False):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x 

def nn_base(input_tensor=None, trainable=False):


    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    # Block 1
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv1')(img_input)
    x = Conv2D(64, (3, 3), activation='relu', padding='same', name='block1_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block1_pool')(x)

    # Block 2
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv1')(x)
    x = Conv2D(128, (3, 3), activation='relu', padding='same', name='block2_conv2')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block2_pool')(x)

    # Block 3
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv1')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv2')(x)
    x = Conv2D(256, (3, 3), activation='relu', padding='same', name='block3_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block3_pool')(x)

    # Block 4
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block4_conv3')(x)
    x = MaxPooling2D((2, 2), strides=(2, 2), name='block4_pool')(x)

    # Block 5
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv1')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv2')(x)
    x = Conv2D(512, (3, 3), activation='relu', padding='same', name='block5_conv3')(x)
    # x = MaxPooling2D((2, 2), strides=(2, 2), name='block5_pool')(x)

    return x 

def nn_base(input_tensor=None, trainable=False):

    # Determine proper input shape
    if K.image_dim_ordering() == 'th':
        input_shape = (3, None, None)
    else:
        input_shape = (None, None, 3)

    if input_tensor is None:
        img_input = Input(shape=input_shape)
    else:
        if not K.is_keras_tensor(input_tensor):
            img_input = Input(tensor=input_tensor, shape=input_shape)
        else:
            img_input = input_tensor

    if K.image_dim_ordering() == 'tf':
        bn_axis = 3
    else:
        bn_axis = 1

    x = ZeroPadding2D((3, 3))(img_input)

    x = Convolution2D(64, (7, 7), strides=(2, 2), name='conv1', trainable = trainable)(x)
    x = FixedBatchNormalization(axis=bn_axis, name='bn_conv1')(x)
    x = Activation('relu')(x)
    x = MaxPooling2D((3, 3), strides=(2, 2))(x)

    x = conv_block(x, 3, [64, 64, 256], stage=2, block='a', strides=(1, 1), trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='b', trainable = trainable)
    x = identity_block(x, 3, [64, 64, 256], stage=2, block='c', trainable = trainable)

    x = conv_block(x, 3, [128, 128, 512], stage=3, block='a', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='b', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='c', trainable = trainable)
    x = identity_block(x, 3, [128, 128, 512], stage=3, block='d', trainable = trainable)

    x = conv_block(x, 3, [256, 256, 1024], stage=4, block='a', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='b', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='c', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='d', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='e', trainable = trainable)
    x = identity_block(x, 3, [256, 256, 1024], stage=4, block='f', trainable = trainable)

    return x