Keras input shape ValueError

Question

I have a problem and at the same time a question. I want to make an image classifier with Keras using Theano as Backend and a Sequential model.

>>> keras.__version__
'2.0.1'  
>>> theano.__version__
'0.9.0'

My input shape: INPUT_SHAPE = (3, 28, 28) #depth, size, size

Let's come to my problem. If I run my script at Windows 7 32 Bit, it gives me the error below out:

ValueError: ('The specified size contains a dimension with value <= 0', (-1024, 512))

If run it with the the input shape: INPUT_SHAPE = (28, 28, 3) #size, size, depth
It gives me out this error below:

ValueError: Error when checking model input: expected conv2d_1_input to have shape (None, 48, 48, 3) but got array with shape (1000, 3, 48, 48)

If I run the code on Elementary OS 64 Bit, it runs without any problems (INPUT_SHAPE = (3, 28, 28)).

My keras.json file for windows is:

{
  "backend": "theano",
  "epsilon": 1e-07,
  "floatx": "float32",
  "image_dim_ordering": "tf"
}

So, my question is: Is there such a big difference between different Operating Systems or where is my mistake? Just to remind, I used exactly the same code for both systems.

Answer 1

If your problem is not solved yet try using: from keras import backend as K K.set_image_dim_ordering('th') This would work good if you wish to use theano backend and have to use channels first configuration for image dimension ordering.

Answer 2

The problem you are having has to do with the expected dimension ordering.

• Tensorflow ordering (tf): Shapes are expected to be (size_lines,size_columns,channel)
• Theano ordering (th): Shapes are expected to be (channel,size_lines,size_columns)

If you change the ordering line in the keras.json file to "image_dim_ordering": "th" it should work. (i'd bet that's what's in your Elementary OS keras.json).