Generalized total variation iterative constraint strategy in limited angle optical diffraction tomography

Abstract

Due to incompleteness of input data inherent to Limited Angle Tomography (LAT), specific additional constraints are usually employed to suppress image artifacts. In this work we demonstrate a new two-stage regularization strategy, named Generalized Total Variation Iterative Constraint (GTVIC), dedicated to semi-piecewise-constant objects. It has been successfully applied as a supplementary module for two different reconstruction algorithms: an X-ray type solver and a diffraction-wise solver. Numerical tests performed on a detailed phantom of a biological cell under conical illumination pattern show significant reduction of axial blurring in the reconstructed refractive index distribution after GTVIC is added. Analogous results were obtained with experimental data.

Holographic tomography with scanning of illumination: space-domain reconstruction for spatially invariant accuracy

“…Although the experimental implementation of the linear illumination scenario is relatively simple, its transfer function is highly anisotropic, which leads to strong artefacts in tomographic reconstructions. In this paper, we calculate c for another popular and more beneficial tomographic system, which applies conical illumination scenario [14,23,24] (see Appendix), where the illumination vector with a fixed inclination angle rotates around the optical axis in a full angle. The comparison of c for both illumination scenarios is presented in Fig.…”

“…We do not intend to fill in the missing information as it is done in [12][13][14]. Instead, the paper focuses on the ability of the tomographic algorithms to properly recover those object frequencies that are directly accessible to a given ISC-HT system.…”

“…The problem has been already addressed, e.g. in [12,13] and with a recent two-stage strategy based on the regularization technique [14].…”

“…Regardless of its pros and cons, numerous scientific publications [1,3,4,13,14] and commercial implementations [15,16] clearly demonstrate the potential of ISC-HT for 3D imaging in various biomedical application fields. Currently, ISC-HT systems are constantly further improved and evaluated with increasingly demanding samples such as single living cells with complex shapes or cell clusters.…”

“…DI. They are also applied to experimental measurement data from a pancreatic cancer cell that were obtained with a Mach-Zehnder digital holographic microscope utilizing a conical illumination scenario [14,23,24]. The ISC-HT setup with the applied illumination scenario is characterized in this paper by providing the analytical formulas for its tomographic transfer function, which represents an additional important novelty of this work.…”