1
votes

The following code is giving me a graph disconnected error but I cant work out where it is coming from and am not sure how to go about debugging. The error is being thrown on the last line decoder = Model(latentInputs, outputs, name="decoder"), I have compared it to working code that I modified but to no avail.

from tensorflow.keras.layers import BatchNormalization
from tensorflow.keras.layers import Conv2D
from tensorflow.keras.layers import Conv2DTranspose
from tensorflow.keras.layers import LeakyReLU
from tensorflow.keras.layers import ReLU
from tensorflow.keras.layers import Input
from tensorflow.keras.layers import GlobalAveragePooling2D
from tensorflow.keras.layers import UpSampling2D
from tensorflow.keras.layers import Flatten
from tensorflow.keras.layers import Dense
from tensorflow.keras.layers import GaussianNoise
from tensorflow.keras.layers import Flatten
from tensorflow.keras.layers import Reshape
from tensorflow.keras.layers import Add
from tensorflow.keras.models import Model
from tensorflow.keras import backend as K
import tensorflow as tf
import numpy as np

width=256
height=256
depth=3
inputShape = (height, width, depth)
chanDim = -1
filter_size = 3
latentDim = 512

# initialize the input shape to be "channels last" along with
# the channels dimension itself

inputShape = (height, width, depth)
chanDim = -1

# define the input to the encoder
inputs = Input(shape=inputShape)
x = GaussianNoise(0.2)(inputs)

x = Conv2D(128, filter_size, strides=1, padding="same")(x)

x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)
layer_1 = Conv2D(128, filter_size, strides=2, padding="same")(x)


x = BatchNormalization(axis=chanDim)(layer_1)
x = LeakyReLU(alpha=0.2)(x)
layer_2 = Conv2D(128, filter_size, strides=2, padding="same")(x)

x = BatchNormalization(axis=chanDim)(layer_2)
x = LeakyReLU(alpha=0.2)(x)
layer_3 = Conv2D(128, filter_size, strides=2, padding="same")(x)


x = BatchNormalization(axis=chanDim)(layer_3)
x = LeakyReLU(alpha=0.2)(x)
layer_4 = Conv2D(128, filter_size, strides=2, padding="same")(x)


x = BatchNormalization(axis=chanDim)(layer_4)
x = LeakyReLU(alpha=0.2)(x)
layer_5 = Conv2D(128, filter_size, strides=2, padding="same")(x)


x = BatchNormalization(axis=chanDim)(layer_5)
x = LeakyReLU(alpha=0.2)(x)
layer_6 = Conv2D(128, filter_size, strides=2, padding="same")(x)

x = BatchNormalization(axis=chanDim)(layer_6)
x = LeakyReLU(alpha=0.2)(x)
layer_7 = Conv2D(128, filter_size, strides=2, padding="same")(x)

latent = Flatten()(layer_7)
# flatten the network and then construct our latent vector
volumeSize = K.int_shape(layer_7)

# build the encoder model
encoder = Model(inputs, latent, name="encoder")
encoder.summary()   
# start building the decoder model which will accept the
# output of the encoder as its inputs
#%%
latentInputs = Input(shape=(np.prod(volumeSize[1:]),))
x = Reshape((volumeSize[1], volumeSize[2], volumeSize[3]))(latentInputs)

dec_layer_7 = Add()([x, layer_7])
x = Conv2DTranspose(128, filter_size, strides=2, padding="same")(dec_layer_7)
x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)

dec_layer_6 = Add()([x, layer_6])
x = Conv2DTranspose(128, filter_size, strides=2, padding="same")(dec_layer_6)
x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)

dec_layer_5 = Add()([x, layer_5])
x = Conv2DTranspose(128, filter_size, strides=2, padding="same")(dec_layer_5)
x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)

dec_layer_4 = Add()([x, layer_4])
x = Conv2DTranspose(128, filter_size, strides=2, padding="same")(dec_layer_4)
x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)

dec_layer_3 = Add()([x, layer_3])
x = Conv2DTranspose(128, filter_size, strides=2, padding="same")(dec_layer_3)
x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)

dec_layer_2 = Add()([x, layer_2])
x = Conv2DTranspose(128, filter_size, strides=2, padding="same")(dec_layer_2)
x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)

dec_layer_1 = Add()([x, layer_1])
x = Conv2DTranspose(128, filter_size, strides=2, padding="same")(dec_layer_1)
x = BatchNormalization(axis=chanDim)(x)
x = LeakyReLU(alpha=0.2)(x)
outputs = Conv2DTranspose(depth, filter_size, padding="same")(x)
# apply a single CONV_TRANSPOSE layer used to recover the
# original depth of the image
# =============================================================================
# outputs = ReLU(max_value=1.0)(x)
# =============================================================================

# build the decoder model
decoder = Model(latentInputs, outputs, name="decoder")

Error is:

ValueError: Graph disconnected: cannot obtain value for tensor Tensor("input_37:0", shape=(None, 256, 256, 3), dtype=float32) at layer "input_37". The following previous layers were accessed without issue: []
1

1 Answers

1
votes

layer_7 refers to another model... you have to provide input for layer_7 in your decoder. a solution can be to define your decoder in this way

decoder = Model([latentInputs, encoder.input], outputs, name="decoder")

here the full example: https://colab.research.google.com/drive/1W8uLy49H_8UuD9DGZvtP7Md1f4ap3u6A?usp=sharing