OCT sidelobe suppression method based on dual-path phase sinusoidal modulation and minimum value fusion

In optical coherence tomography (OCT) images, sidelobe artifacts are weaker signals that emanate from regions adjacent to high-intensity sample signals. These artifacts do not correspond to actual tissue structures and can be easily misinterpreted as low-intensity sample signals, which affects the clarity of OCT images. Current methods for sidelobe suppression are limited in effectiveness or in their ability to handle complex samples. In this paper, we propose an OCT sidelobe suppression method based on dual-path phase sinusoidal modulation and minimum value fusion. In the two operation paths, the Hilbert transform and the inverse Hilbert transform are used to extract the phase angle, respectively. The sine value of the phase angle is used to modulate the axial intensity distribution. Finally, the minimum value of the two modulated curves is extracted using minimum-value fusion to achieve sidelobe suppression. The processing results of OCT images of coverslip, tape, and fingertip skin samples show that the proposed method can achieve a maximum sidelobe suppression effect of 50.1 dB, and the full width at half-maximum of the point spread function is reduced to 53% of that of the traditional methods, thereby achieving an improvement in image clarity.