Python backend.spatial_2d_padding方法代码示例

# 需要导入模块: from keras import backend [as 别名]
# 或者: from keras.backend import spatial_2d_padding [as 别名]
def crosschannelnormalization(alpha=1e-4, k=2, beta=0.75, n=5, **kwargs):
    """
    This is the function used for cross channel normalization in the original
    Alexnet
    """

    def f(X):
        b, ch, r, c = X.shape
        half = n // 2
        square = K.square(X)
        extra_channels = K.spatial_2d_padding(K.permute_dimensions(square, (0, 2, 3, 1))
                                              , (0, half))
        extra_channels = K.permute_dimensions(extra_channels, (0, 3, 1, 2))
        scale = k
        for i in range(n):
            scale += alpha * extra_channels[:, i:i + ch, :, :]
        scale = scale ** beta
        return X / scale

    return Lambda(f, output_shape=lambda input_shape: input_shape, **kwargs) 

# 需要导入模块: from keras import backend [as 别名]
# 或者: from keras.backend import spatial_2d_padding [as 别名]
def crosschannelnormalization(alpha = 1e-4, k=2, beta=0.75, n=5,**kwargs):
    """
    This is the function used for cross channel normalization in the original
    Alexnet
    """
    def f(X):
        b, ch, r, c = X.shape
        half = n // 2
        square = K.square(X)
        extra_channels = K.spatial_2d_padding(K.permute_dimensions(square, (0,2,3,1))
                                              , (0,half))
        extra_channels = K.permute_dimensions(extra_channels, (0,3,1,2))
        scale = k
        for i in range(n):
            scale += alpha * extra_channels[:,i:i+ch,:,:]
        scale = scale ** beta
        return X / scale

    return Lambda(f, output_shape=lambda input_shape:input_shape,**kwargs) 

# 需要导入模块: from keras import backend [as 别名]
# 或者: from keras.backend import spatial_2d_padding [as 别名]
def crosschannelnormalization(alpha = 1e-4, k=2, beta=0.75, n=5,**kwargs):
    """
    This is the function used for cross channel normalization in the original
    Alexnet
    """
    def f(X):
        b, ch, r, c = X.shape
        half = n // 2
        square = K.square(X)
        extra_channels = K.spatial_2d_padding(K.permute_dimensions(square, (0,2,3,1)))
        extra_channels = K.permute_dimensions(extra_channels, (0,3,1,2))
        scale = k
        for i in range(n):
            scale += alpha * extra_channels[:,i:i+ch,:,:]
        scale = scale ** beta
        return X / scale

    return Lambda(f, output_shape=lambda input_shape:input_shape,**kwargs) 

# 需要导入模块: from keras import backend [as 别名]
# 或者: from keras.backend import spatial_2d_padding [as 别名]
def inst_weight(output_y, output_x, output_dr, output_dl, config=None):
    dy = output_y[:,2:,2:]-output_y[:, :-2,2:] + \
         2*(output_y[:,2:,1:-1]- output_y[:,:-2,1:-1]) + \
         output_y[:,2:,:-2]-output_y[:,:-2,:-2]
    dx = output_x[:,2:,2:]- output_x[:,2:,:-2] + \
         2*( output_x[:,1:-1,2:]- output_x[:,1:-1,:-2]) +\
         output_x[:,:-2,2:]- output_x[:,:-2,:-2]
    ddr=  (output_dr[:,2:,2:]-output_dr[:,:-2,:-2] +\
           output_dr[:,1:-1,2:]-output_dr[:,:-2,1:-1]+\
           output_dr[:,2:,1:-1]-output_dr[:,1:-1,:-2])*K.constant(2)
    ddl=  (output_dl[:,2:,:-2]-output_dl[:,:-2,2:] +\
           output_dl[:,2:,1:-1]-output_dl[:,1:-1,2:]+\
           output_dl[:,1:-1,:-2]-output_dl[:,:-2,1:-1])*K.constant(2)
    dpred = K.concatenate([dy,dx,ddr,ddl],axis=-1)
    dpred = K.spatial_2d_padding(dpred)
    weight_fg = K.cast(K.all(dpred>K.constant(config.GRADIENT_THRES), axis=3, 
                          keepdims=True), K.floatx())
    
    weight = K.clip(K.sqrt(weight_fg*K.prod(dpred, axis=3, keepdims=True)), 
                    config.WEIGHT_AREA/config.CLIP_AREA_HIGH, 
                    config.WEIGHT_AREA/config.CLIP_AREA_LOW)
    weight +=(1-weight_fg)*config.WEIGHT_AREA/config.BG_AREA
    weight = K.conv2d(weight, K.constant(config.GAUSSIAN_KERNEL),
                      padding='same')
    return K.stop_gradient(weight) 

# 需要导入模块: from keras import backend [as 别名]
# 或者: from keras.backend import spatial_2d_padding [as 别名]
def _deconv(self, X, lname, d_switch, feat_map=None):
        o_width, o_height = self[lname].output_shape[-2:]

        # Get filter size
        f_width = self[lname].W_shape[2]
        f_height = self[lname].W_shape[3]

        # Compute padding needed
        i_width, i_height = X.shape[-2:]
        pad_width = (o_width - i_width + f_width - 1) / 2
        pad_height = (o_height - i_height + f_height - 1) / 2

        assert isinstance(
            pad_width, int), "Pad width size issue at layer %s" % lname
        assert isinstance(
            pad_height, int), "Pad height size issue at layer %s" % lname

        # Set to zero based on switch values
        X[d_switch[lname]] = 0
        # Get activation function
        activation = self[lname].activation
        X = activation(X)
        if feat_map is not None:
            print("Setting other feat map to zero")
            for i in range(X.shape[1]):
                if i != feat_map:
                    X[:, i, :, :] = 0
            print("Setting non max activations to zero")
            for i in range(X.shape[0]):
                iw, ih = np.unravel_index(
                    X[i, feat_map, :, :].argmax(), X[i, feat_map, :, :].shape)
                m = np.max(X[i, feat_map, :, :])
                X[i, feat_map, :, :] = 0
                X[i, feat_map, iw, ih] = m
        # Get filters. No bias for now
        W = self[lname].W
        # Transpose filter
        W = W.transpose([1, 0, 2, 3])
        W = W[:, :, ::-1, ::-1]
        # CUDNN for conv2d ?
        conv_out = K.T.nnet.conv2d(
            input=self.x, filters=W, border_mode='valid')
        # Add padding to get correct size
        pad = K.function([self.x], K.spatial_2d_padding(
            self.x, padding=(pad_width, pad_height), dim_ordering="th"))
        X_pad = pad([X])
        # Get Deconv output
        deconv_func = K.function([self.x], conv_out)
        X_deconv = deconv_func([X_pad])
        assert X_deconv.shape[-2:] == (o_width, o_height),\
            "Deconv output at %s has wrong size" % lname
        return X_deconv