Image Contrast Enhancement by Using LED Annular Oblique Illumination in Bright-Field Microscopy

Autor: Xiao Ma, Pan Qi, Zhifeng Wu, Ying Yang, Chengsen Li, Jingang Zhong
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Photonics, Vol 10, Iss 4, p 404 (2023)
Druh dokumentu: article
ISSN: 10040404
2304-6732
DOI: 10.3390/photonics10040404
Popis: Köhler illumination is the most used method for evenly illuminating a sample in bright-field microscopy. However, Köhler illumination cannot provide optimum contrast and high resolution simultaneously. The image contrast for Köhler illumination can be enhanced at the expense of lateral resolution. In this paper, we discuss the main causes of contrast loss with Köhler illumination by simulating unsymmetrical interference, incoherent superposition, and modulation transfer function. We present a method to increase the image contrast by combining the annular oblique illumination with normalization and blind deconvolution. With the progress of optoelectronic devices, the greater advantages of annular oblique illumination will become apparent. The experimental results achieved by using LED annular oblique illumination prove the feasibility of the proposed method.
Databáze: Directory of Open Access Journals