Image Reconstruction Combined With Interference Removal Using a Mixed-Domain Proximal Operator

In certain imaging systems, frames of acquired raw data are preprocessed with a filtering stage before being processed with an image reconstruction stage. During these sequential stages, distortion may arise if valid signal cannot adequately be distinguished from interference. To avoid distortion, a mixed-domain proximal operator is mathematically formulated, which permits interference to be separated from data concurrently during a combined processing stage. The technique is demonstrated with an application involving optoacoustic imaging. Reconstruction is performed with an accelerated proximal gradient method. Total-variation minimization is used to promote smoothness in the image domain. In the data domain, interference is modeled as a low-rank matrix, which corresponds to a few time dependent interference components being coupled to each channel by determined amounts. Results are presented that demonstrate the ability to separate interference on a digital phantom used to simulate optoacoustic signals.