Improved three-dimensional localization of multiple small objects in close proximity in digital holography.

Area of Science:

• Optics and Photonics
• Digital Holography
• 3D Imaging

Background:

• Accurate three-dimensional (3D) localization of small objects in large-field-of-view digital holographic reconstructions is critical for various applications.
• Traditional focus metrics based on intensity gradients or sparsity struggle with depth accuracy when multiple objects are present.

Purpose of the Study:

• To propose and validate a novel method for enhanced 3D object localization in digital holography.
• To overcome the limitations of existing focus metrics in scenarios with multiple nearby objects.

Main Methods:

• Development of a new 3D localization approach evaluating the complex reconstructed holographic volume.
• Comparison with intensity gradient- and sparsity-based focus metrics.

Main Results:

• The proposed method significantly reduces depth positional error for single objects.
• A notable improvement in axial resolution was achieved for multiple objects in close proximity.
• Simulations and experimental data confirmed the method's efficacy.

Conclusions:

• Evaluating the complex reconstructed volume offers a more accurate alternative for 3D localization in digital holography.
• This method enhances the ability to resolve and localize closely spaced objects, improving 3D imaging capabilities.