A method of designing an element for the manipulation of waves, comprises: accessing a computer readable medium storing a machine learning procedure, having a plurality of learnable weight parameters. A first plurality of the weight parameters corresponds to the element, and a second plurality of the weight parameters correspond to an image processing. The method comprises accessing a computer readable medium storing training imaging data, and training the machine learning procedure on the training imaging data, so as to obtain values for at least the first plurality of the weight parameters.