Abstract

We propose a Bessel-like composite vortex filter to perform high-contrast and power-controlled anisotropic edge enhancement with shadow-effect-free and low background noise. The background noise, which is commonly found and strongly decreases the filtered image quality in previous anisotropic vortex filters, is effectively reduced by suppressing the side lobes of the system point spread function, thereby increasing the image edge contrast to 0.98. The shadow effect is totally eliminated by keeping the radial symmetry of the filtering process, which makes edges sharper and improves image resolution. By introducing a weighting factor between two opposite vortex filter components, the power of edge enhancement becomes controllable. Numerical simulations and experimental results prove that the proposed filter achieves higher-contrast edge enhancement for both phase-contrast and amplitude-contrast objects.

© 2019 Optical Society of America

Image edge enhancement using Airy spiral phase filter

Yi Zhou, Shaotong Feng, Shouping Nie, Jun Ma, and Caojin Yuan
Opt. Express 24(22) 25258-25268 (2016)

Amp-vortex edge-camera: a lensless multi-modality imaging system with edge enhancement

Lina Li, Jianshe Ma, Da Sun, Zhanquan Tian, Liangcai Cao, and Ping Su
Opt. Express 31(14) 22519-22531 (2023)

Selective edge enhancement using anisotropic vortex filter

Manoj Kumar Sharma, Joby Joseph, and Paramasivam Senthilkumaran
Appl. Opt. 50(27) 5279-5286 (2011)

Edge enhancement in three-dimensional vortex imaging based on FINCH by Bessel-like spiral phase modulation

Jiuru He, Pengwei Zhang, Jianpo Su, Junqiao Wang, Yongzhi Tian, Yongsheng Hu, and Fengying Ma
Opt. Express 32(2) 1438-1450 (2024)

Anisotropic edge enhancement with spiral zone plate under femtosecond laser illumination

Yi Zhou, Shaotong Feng, Shouping Nie, Jun Ma, and Caojin Yuan
Appl. Opt. 56(10) 2641-2648 (2017)