@inproceedings{b0e5c435164943a9abb33975cb68046f,
title = "Photoacoustic reconstruction from photothermal measurements",
abstract = "Photothermal measurements with an infrared camera enable a fast and contactless part inspection. The main drawback of existing reconstruction methods is the degradation of the spatial resolution with increasing imaging depth, which results in blurred images for deeper lying structures. In this work, we propose an efficient image reconstruction strategy that allows prior information to be included to overcome the diffusion-based information loss. Following the virtual wave concept, in a first step we reconstruct from the measured photothermal signal an acoustic wave field that satisfies the standard wave equation. This wave is called a virtual one, because it is not the measured acoustic wave but mathematically calculated from the temperature signal measured on the sample surface. In the second step, stable and efficient reconstruction methods developed for photoacoustic tomography are used. We compensate for the loss of information in thermal measurements by incorporating the prior information positivity and sparsity. For that purpose we combine circular projections with an iterative regularization scheme. Using experimental data, this work demonstrates that the quality of the reconstruction based on photothermal measurements can be significantly enhanced. The main goal of this work was to illustrate that prior information significantly improves the regularized solution and, hence, the reconstructed field. Using an iterative non-linear regularization method, the prior information positivity and sparsity could be incorporated. The regularization and reconstruction results show that respecting information available about the data significantly increases the quality of the regularized solution.",
keywords = "Image reconstruction, Inverse problem, Optoacoustic, Photoacoustic, Regularization, Thermography",
author = "Peter Burgholzer and Gregor Thummerer and Guenther Mayr and Markus Haltmeier",
note = "Funding Information: The financial support by the Austrian Federal Ministry of Science, Research and Economy and the National Foundation for Research, Technology and Development is gratefully acknowledged. Furthermore, this work has been supported by the project multimodal and in-situ characterization of inhomogeneous materials (MiCi), by the Federal Government of Upper Austria and the European Regional Development Fund (EFRE) in the framework of the EU-program IWB2020. Financial support was provided by the Austrian Research Funding Association (FFG) under the scope of the COMET program within the research project “Photonic Sensing for Smarter Processes (PSSP)” (contract #871974).This program is promoted by BMVIT, BMDW, the Federal State of Upper Austria and the Federal State of Styria, represented by SFG. Parts of this work have been supported by the Austrian Science Fund (FWF), projects P 30747-N32 and P 33019-N. Publisher Copyright: {\textcopyright} COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.; Photons Plus Ultrasound: Imaging and Sensing 2021 ; Conference date: 06-03-2021 Through 11-03-2021",
year = "2021",
doi = "10.1117/12.2585358",
language = "English",
series = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",
publisher = "SPIE",
editor = "Oraevsky, {Alexander A.} and Wang, {Lihong V.}",
booktitle = "Photons Plus Ultrasound",
address = "United States",
}