Keras ValueError: Input 0 is incompatible with layer conv2d_1: expected ndim=4, found ndim=5

Question

I have checked all the solutions, but still, I am facing the same error. My training images shape is (26721, 32, 32, 1) , which I believe it is 4 dimension, but I don't know why error shows it is 5 dimension.

 model = Sequential()

 model.add(Convolution2D(16, 5, 5, border_mode='same', input_shape= input_shape ))

So this is how I am defining model.fit_generator

model.fit_generator(train_dataset, train_labels, nb_epoch=epochs, verbose=1,validation_data=(valid_dataset, valid_labels), nb_val_samples=valid_dataset.shape[0],callbacks=model_callbacks)

Answer 1

The problem is input_shape .

It should actually contain 3 dimensions only. And internally keras will add the batch dimension making it 4.

Since you probably used input_shape with 4 dimensions (batch included), keras is adding the 5th.

You should use input_shape=(32,32,1) .

Answer 2

The problem is with input_shape . Try adding an extra dimension/channel for letting keras know that you are working on a grayscale image ie --> 1

input_shape= (56,56,1) . Probably if you are using a normal Deep learning model then it won't raise an issue but for Convnet it does.

Answer 3

For reshape the data we need to add fourth dimensions ie changing from (6000,28,28) to (6000,28,28,1)

My code is:

img_rows=x_train[0].shape[0]
img_cols=x_test[0].shape[1]

X_train=x_train.reshape(x_train.shape[0],img_rows,img_cols,1)

X_test=x_test.reshape(x_test.shape[0],img_rows,img_cols,1)


Input_shape=(img_rows,img_cols,**).  *->  I forgot to put 1 here.

I have face the same problem

Input 0 is incompatible with layer conv2d_4 : except ndim=4 ,found ndim=3

I solved this problem by simply putting value in the input shape

Input_shape=(img_rows,img_cols,1)#store the shape of single image.

With this problem is solved

Answer 4

you can use :

train_dataset= train_dataset.reshape(-1,32,32,1)

and now you can use input_shape(32,32,1) in the algorithm.

Answer 5

Here you need to check the "channels_first" whenever CNN is used as 2d,Also reshape your train_data and test data as:

if K.image_data_format() == 'channels_first':   #check for channels_first
 train_img.reshape(train_img.shape[0],1,x,x)
 Input_shape=(1,x,x)                            #In your case x is 32
else:
 train_img.reshape(train_img.shape[0],x,x,1)
 Input_shape=(x,x,1)

Answer 6

I have faced the same problem

Input 0 is incompatible with layer conv2d_4 : except ndim=4 ,found ndim=3

I solved this problem by simply putting value in the input shape

Input_shape=(img_rows,img_cols,1)#store the shape of single image. .. & the problem is solved