Keras CNN image input and output
I know this question was asked sometime ago. I took a look at the diagram and the example code. First, the example code is way off. Here's a description to help those curious how to understand the diagram.

The diagram (architecture) shows only the frontend of a CNN. That's the convolutional layers. On the leftside are a series of VGG convolution blocks. The links to the right side are identity links between the VGG convolution blocks, which pass through their own convolution before being matrix added into the output of the convolution block. The addition of the convolution on the identity link makes it a variant of a ResNet architecture.

The UV 224x224x2 would be the output from the convolutional frontend. It would then be flattened and passed into the DNN layers.