Digital-optical computational imaging capable of end-point logic operations

<jats:p>In this study, digital-optical computational imaging is proposed for object data transmission with a capability to achieve end-point logic operations over free-space data transmission. The framework is regarded as an extension of computational imaging using digital-optical codes originally developed for digital optical computing. Spatial code patterns for optical logic operations are extended to digital-optical codes in the temporal and spectral domains. The physical form of the digital-optical codes is selected, as appropriate, for the situation in use, and different forms can be combined to increase the data-transmission bandwidth. The encoded signals are transferred over free space and decoded by a simple procedure on the destination device, thus enabling logic operations at the end-point of the data transmission. To utilize the benefits of digital processing, a data-transfer mode is introduced which assigns preprocessing for the signals to be encoded and the end-point processing. As a demonstration of the proposed method, an experimental testbed was constructed assuming data transmission from sensor nodes to a gateway device appearing in the Internet of Things. In the experiment, encrypted signals of the sensor nodes, which were encoded by spatial digital-optical codes on RGB channels, were captured as an image, and the original signals were retrieved correctly by an end-point exclusive OR operation.</jats:p>