tensor shape mismatch error when height and width not equals to 512

[maomaozi]

when I try to change img_width to 768,I got this error:

ValueError: Input 0 of layer "model_1" is incompatible with the layer: expected shape=(None, 64, 64, 4), found shape=(1, 64, 96, 4)

[maomaozi]

I found I made a mistake while set the model parameters