Preprocessing in digital lensless holographic microscopy for intensity reconstructions with enhanced contrast

Area of Science:

• Microscopy and Imaging Technologies
• Optical Physics
• Computational Imaging

Background:

• Digital lensless holographic microscopy (DLHM) offers label-free imaging but often suffers from low contrast in reconstructions.
• Enhancing contrast is crucial for accurate visualization and analysis of microscopic specimens in DLHM.

Purpose of the Study:

• To present a novel numerical method for improving the contrast of intensity hologram reconstructions in DLHM.
• To quantitatively assess the contrast enhancement achieved by the proposed method.

Main Methods:

• A preprocessing technique involving mathematical manipulation and sharpening of in-line hologram and reference images.
• Application of the method to recorded holograms and validation using modeled data.

Main Results:

• Achieved a 25% improvement in contrast for intensity reconstructions compared to conventional methods.
• Successfully demonstrated the method on polystyrene spheres and a section of a Drosophila melanogaster fly head.

Conclusions:

• The presented numerical method effectively enhances image contrast in DLHM.
• The technique offers a valuable tool for improving the quality of holographic microscopy reconstructions for biological and material science applications.