I want to train a deep network starting with the following layer:
model = Sequential()
model.add(Conv2D(32, 3, 3, input_shape=(32, 32, 3)))
I got the same error while working with mnist data set, looks like a problem with the dimensions of X_train. I added another dimension and it solved the purpose.
X_train, X_test, \ y_train, y_test = train_test_split(X_reshaped, y_labels, train_size = 0.8, random_state = 42)
X_train = X_train.reshape(-1,28, 28, 1)
X_test = X_test.reshape(-1,28, 28, 1)