In[]:=
NetModel["CycleGAN Photo-to-Van Gogh Translation"]
Out[]=
NetChain

Input
port:
image
Output
port:
image

In[]:=
netEnc=NetEncoder"Image",ImageDimensions

Out[]=
NetEncoder

Type:
Image
Output:
array
(size: 3×250×400)

In[]:=
resizedNet=NetReplacePart[NetModel["CycleGAN Photo-to-Van Gogh Translation"],{"Input"->netEnc,"Output"->NetDecoder[{"Image"}]}]
Out[]=
NetChain

Input
port:
image
Output
port:
image

In[]:=
resizedNet

Out[]=