Sub-Diffraction Imaging Using Fourier Ptychography and Structured Sparsity

We consider the problem of super-resolution for sub-diffraction imaging. We adapt conventional Fourier ptychographic approaches, for the case where the images to be acquired have an underlying structured sparsity. We propose some sub-sampling strategies which can be easily adapted to existing ptychographic setups. We then use a novel technique called CoPRAM with some modifications, to recover sparse (and block sparse) images from sub-sampled pty-chographic measurements. We demonstrate experimentally that this algorithm performs better than existing phase retrieval techniques, in terms of quality of reconstruction, using fewer number of samples.