Digital holographic microscopy is a powerful label-free imaging technique that enables quantitative measurement of optical phase, morphology, and dynamics of biological specimens. Despite its strong potential, its adoption in biological laboratories remains limited by the lack of accessible, integrated, and user-friendly software that supports the full workflow, from hologram acquisition and numerical reconstruction to quantitative analysis and visualization.
HoloBio is a comprehensive and modular software platform that bridges this gap. HoloBio integrates hologram reconstruction, phase compensation, numerical propagation, speckle analysis, quantitative phase imaging, particle tracking, and microstructure characterization within a unified graphical interface. The platform supports both offline and real-time operation and allows users to interactively explore amplitude, phase, and derived physical maps without requiring advanced programming or optical expertise. Using experimental biological samples, we demonstrate that HoloBio enables reliable, reproducible, and quantitative biological analysis. By providing an open, extensible, and user-oriented environment, HoloBio lowers the barrier to adopting digital holographic microscopy in biological and biomedical research, facilitating reproducible workflows and accelerating data-driven discovery
HoloBio is an open-source Python library and GUI for quantitative analysis in Digital Holographic Microscopy (DHM). It supports real-time and offline modes, various optical setups (lens-based and lensless), and provides advanced tools for analyzing biological samples.
More information and Github repository at: https://github.com/SOPHIA-Research-Lab/HoloBio
HoloBio Manual: https://github.com/SOPHIA-Research-Lab/HoloBio/blob/main/Complementary_info/User_Manual.pdf
The OpenSRQPI App is an open-access, GUI-based computational platform for super-resolution reconstruction in QPI using both structured and oblique illumination. Whereas open-source tools for structured illumination microscopy (SIM), including fairSIM, SIMToolbox, and Open-3DSIM, have enabled widespread adoption of fluorescent-based SIM in life sciences by lowering computational barriers and offering robust image validation workflows, such resources are notably absent in the domain of QPI. Unlike qualitative fluorescence SIM imaging, QPI requires precise phase estimation across the entire field of view, where even small inaccuracies can distort quantitative analysis.
This repository hosts the complete distribution of a MATLAB application developed in version R2025a, designed for advanced processing and compensation of digital holograms acquired under oblique illumination and structured illumination conditions. To ensure broad accessibility, we provide not only the open-source code but also a compiled standalone executable and a packaged installer, allowing users to run the software without requiring a full MATLAB environment. In addition, the repository includes a set of test datasets to facilitate immediate experimentation and validation of the app’s functionality. For oblique illumination, we supply simulated holograms both in ideal, noise-free conditions and in noisy scenarios with signal-to-noise ratios (SNR) ranging from 5 to 40, enabling users to evaluate performance across different noise levels. For structured illumination, the test material comprises noise-free simulations alongside real experimental images, offering a comprehensive reference for both synthetic and practical cases. By combining code, executables, and curated datasets, this repository is intended to serve as a complete platform for researchers and practitioners to explore, test, and extend the capabilities of the developed application.
More information and Github repository at: https://github.com/OIRL/OpenSRQPI
Peer-reviewed journal: https://doi.org/10.3390/electronics14224513
Digital Holographic Microscopy (DHM) is a powerful technique for label-free imaging, particularly useful in biomedical applications. However, the accuracy of DHM measurements often depends on compensating for phase aberrations caused by optical setups and sample properties. However, when imaging intricate biological samples, such as those involving high spatial frecuency objects or rapidly changing contrast details, conventional phase compensation method usually fail. Therefore, this method is specially suited to properly compensate and image these kinds of samples.
This repository implements the Vortex-Legendre Method, a two-step computational approach that:
Utilizes numerical optical vortices for precise sub-pixel localization of diffraction orders, enabling robust tilt aberration correction.
Applies Legendre Polynomial Fitting (LPF) to address residual higher-order aberrations, ensuring fully compensated phase maps.
More information and Github repository at: https://github.com/sophiaresearchlaboratory/VortexDHM
Peer-reviewed journal: https://doi.org/10.1016/j.optlaseng.2025.109318
In this undergraduate research project, we aim to investigate the performance of the PCA-based method for phase reconstruction in an in-line DHM system. Specifically, we will evaluate the accuracy and robustness of PCA-based phase reconstruction algorithms based on the number of phase-shifted images and the value of the phase step. The PCA algorithm will be tested under both noiseless and noisy conditions to assess its reliability in practical imaging scenarios. This research project seeks to contribute to the understanding of the potential of PCA as a viable method for phase reconstruction in DHM and its applicability in real-world imaging applications.
More information and Github repository at: https://github.com/OIRL/REU-PCA-BlindPS-DHM
Documentation: https://sites.google.com/view/pca-blind-ps-dhm/home
This MATLAB code enables the indirect measurement of the chlorophyll molecules present when a green laser diode illuminates the oil sample. Oil blends can be classified into five classes (no olive oil, light olive oil, medium olive oil, olive oil, and extra virgin olive oil) by quantifying the ratio of the red channel versus the green channel along the laser illumination path from a color image.
More information and Github repository at: https://github.com/OIRL/REU-OliveOilClassification/tree/main
Documentation: https://sites.google.com/view/reu-olive-oil-classification/home
Digital Holographic Microscopy (DHM) enables the three-dimensional (3D) reconstruction of quantitative phase distributions from a defocused hologram. We have developed a synergistic computational framework to simultaneously compensate for the linear tilt introduced in off-axis DHM systems and focus the defocused holograms by minimizing a cost function, providing in-focus reconstructed phase images without phase distortions.
More information and Github repository at: https://github.com/OIRL/3D-QPI-DHM/
Documentation: https://sites.google.com/view/3dqpidhm/home
The proposed Semi-heuristic phase compensation (SHPC) method is an alternative approach for reconstructing phase maps with reduced processing time compared with the brute-force algorithms while avoiding the local-minimum problem of the heuristic proposals. This algorithm is based on nested searches in which the grid size in every iteration is systematically reduced to optimize the compensation time. This algorithm also have a dynamic version called D-SHPC for compensating holographic videos of dynamic samples. Both algorithms are accurate in phase reconstructions and fast enough to compensate full FOV (1280x960 pixels) holograms at rates of 5 FPS.
More information and Github repository at: https://sobandov.github.io/SHPC/
YouTuve videos: https://youtu.be/oN_x9qtwUy0; https://youtu.be/q1RZo6z9k2w; https://youtu.be/254SkoXl11w ://youtu.be/Hyi5vwgYX7
We have proposed a global stress detection framework combining eight HRV features and an RF model with a classifying power of 99% or higher during individual testing using two benchmark datasets (i.e., WESAD and SWELL datasets). The proposed global stress detection framework is available on GitHub. We used Google Collab with Python 3 to investigate the proposed global stress framework. The code was implemented using Python libraries such as TensorFlow, Matplotlib, NumPy, Pandas, and Karas. The computational specs for the algorithm are 12 GB RAM using Google Collaboratory.
More information and Github repository at: https://github.com/OIRL/2023StressModelHRV
Among the optical configuration of the imaging system in DHM, imaging systems operating in a non-telecentric regime are the most common ones. The spherical wavefront introduced by the non-telecentric DHM system must be compensated to provide undistorted phase measurements. Here, we present a clear and simple procedure for a total compensation algorithm for non-telecentric DHM holograms independent of the sample's size (i.e., no requiring sample-free field of view within the hologram). The proposed method has been implemented in MATLAB 2021a and Python 3.7.1. Users of the proposed method should have installed the Optimization and Global Optimization MATLAB toolboxes and the scipy library from Python.
More information and Github repository at: https://github.com/OIRL/noteleDHM-Tool
Documentation: https://sites.google.com/view/noteledhmtool/home?authuser=1
YouTuve video: www.youtube.com/watchv=Hyi5vwgYX7chtps://youtu.be/Hyi5vwgYX7
Confocal microscopes are known for optically removing the out-of-focus information (i.e., blur) in each transverse section of the sample’s volume, providing a more accurate three-dimensional image of thick microscopic samples than widefield microscopes. In this work, we have designed and evaluated a confocal microscope using off-of-shelf optical components from Thorlabs’ catalog, one of the major optical manufacturers. The design and evaluation have been implemented using Zemax OpticStudio, the standard optical system design software. Here, we have also reported a practical protocol for building a confocal microscope using sequential mode.
More information and Github repository at: https://oirl.github.io/Design-Confocal.github.io/
Spectrometers are optical tools to measure the spectral composition of a beam of light. Key features of an optimal spectrometer are: cost, variation of the spot size along the spectral range, spot size compared to the diffraction limit, and minimum presence of aberrations. Here, we present different optical designs to focus the light emerging from a diffraction grating.
More information and Github repository at: https://oirl.github.io/Design-espectometer.github.io/
The hallmark of polarization-sensitive microscopy is the estimation of polarimetric information of samples, making them a suitable tool for detecting and diagnosis different type of cells and tissues in life sciences. In this work, we describe a practical procedure for measuring the Mueller matrix of samples using a bright-field microscope using 36 intensity-based images. The hallmark of the proposed method is the retrieval of the Mueller matrix across the transverse section of a sample, being suitable for analyzing biological samples. The method has been implemented in Python and MATLAB.
More information and Github repository at: https://oirl.github.io/Muller-Matrix-Microscopy/
pyDHM is an open-source Python library aimed at Digital Holographic Microscopy (DHM) applications. The pyDHM is a user-friendly library written in the robust programming language of Python that provides a set of numerical processing algorithms for reconstructing amplitude and phase images for a broad range of optical DHM configurations. The pyDHM implements phase-shifting approaches for in-line and slightly off-axis systems and enables phase compensation for telecentric and non-telecentric systems. In addition, pyDHM includes three propagation algorithms for numerical focusing complex amplitude distributions in DHM and digital holography (DH) setups. We have validated the library using numerical and experimental holograms.
More information and Github repository at: https://catrujilla.github.io/pyDHM/
Examples of how to install and use it are found in our YouTube channel.
pyDHM library structure. The library is composed of utility (1), phase-shifting (2), fully-compensated phase reconstruction (3), and numerical propagation (4) packages.
We present two blind-iterative phase-shifting algorithms in which there is no need for prior knowledge of the phase shifts between the raw holograms. These two approaches provide accurate quantitative phase images in Phase-Shifting Digital Holographic Microscopy (PS-DHM) using three or two raw holograms. The proposed methods are based on the demodulation of the spectral components of the recorded holograms. The hallmarks of our methods are blindness (no prior knowledge of any phase shift), accuracy, and reduced acquisition and processing times leading to a PS-DHM system more suitable for dynamic imaging, as is the case of live cell imaging and colloidal systems.
More information and Github repository at: https://oirl.github.io/Blind-PS-DHM-methods/
Exaple of the phase reconstructions with the two algorithms.
We present a single-shot computational method based on the use of a hybrid median-mean approach for reducing the speckle noise. The proposed method can be applied to both amplitude and phase reconstructed images. This method is based on the combination of multiple median-filtered images with different kernel sizes. Because, for each median-filtered image the speckle position changes, the average of these median-filtered images results in a final image with low speckle contrast and no resolution decrease (e.g., no blurring effect introduced by the median filter). The proposed method has been evaluated experimentally in digital holography and digital holographic microscopy.
More information and Github repository at: https://oirl.github.io/Speckle-Hybrid-median-mean/
Example of the result of denoising process with the algorithm.
The conventional quantitative phase reconstruction in off-axis Digital Holographic Microscopy (DHM) relies on computational processing. Regardless the implementation, any DHM computational processing leads to large processing times, hampering the use of DHM to video-rate renderings of dynamic biological processes. In this work, a conditional generative adversarial network (cGAN) for robust and fast quantitative phase imaging in DHM is reported. The reconstructed phase images provided by the GAN model present stable background levels, enhancing the visualization of the specimens for different experimental conditions. The proposed learning-based method has been trained and validated using human red blood cells. After proper training, the proposed GAN yields to a computationally efficient method, reconstructing DHM images 7X faster than conventional computational approaches.
More information and Github repository at: https://oirl.github.io/cGAN-Digital-Holographic-microscopy/
Example of the result of the CGAN model
tuDHM is an algorithm to recover the complex object information for a single-shot digital holographic microscope (DHM) operating in the telecentric regimen. The algorithm is based on the minimization of a cost function that finds the best numerical conjugated reference beam to compensate the filtered object information, eliminating any undesired phase perturbation due to the tilt between the reference and object waves
More information and Github repository at: https://oirl.github.io/tuDHM/
Graphical flowchart of the algorithm