Application of mathematical morphological filter for noise reduction in photoacoustic imaging

Photoacoustic imaging ( PAI) is a promising imaging technique in preclinical study, which combines both merits of optical and ultrasound imaging. However, PA image quality is seriously suffered from various noises such as random white noise, intrinsic noise of devices and background noise from imaging environment, especially in in-vivo experiments. Regular linear filters like mean filters no longer provide a satisfactory performance. A boosted filter is necessary to degrade the noise level and enhance PA image contrast. In this paper, we applied a nonlinear de-noising filter based on mathematical morphology, which can help smooth the target boundary and well suppress impulse noise in PA images. Phantom and in-vivo experiments in this paper will show the feasibility and performance as a newly-used filter in PA image processing.