Single snapshot of optical properties image quality improvement using anisotropic two-dimensional windows filtering

Abstract

Enagnon Aguénounon, Foudil Dadouche, Wilfried Uhring, Sylvain Gioux, "Single snapshot of optical properties image quality improvement using anisotropic two-dimensional windows filtering," J.Abstract. Imaging methods permitting real-time, wide-field, and quantitative optical mapping of biological tissue properties offer an unprecedented range of applications for clinical use. Following the development of spatial frequency domain imaging, we introduce a real-time demodulation method called single snapshot of optical properties (SSOPs). However, since this method uses only a single image to generate absorption and reduced scattering maps, it was limited by a degraded image quality resulting in artifacts that diminished its potential for clinical use. We present filtering strategies for improving the image quality of optical properties maps obtained using SSOPs. We investigate the effect of anisotropic two-dimensional filtering strategies for spatial frequencies ranging from 0.1 to 0.4 mm −1 directly onto N ¼ 10 hands. Both accuracy and image quality of the optical properties are quantified in comparison with standard, multiple image acquisitions in the spatial frequency domain. Overall, using optimized filters, mean errors in predicting optical properties using SSOP remain under 8.8% in absorption and 7.5% in reduced scattering, while significantly improving image quality. Overall this work contributes to advance real-time, wide-field, and quantitative diffuse optical imaging toward clinical evaluation.

Single snapshot imaging of optical properties using a single-pixel camera: a simulation study

“…Decreasing spatial frequency in SSOP-SPC allows faster acquisition but results in image degradation. 30 This study reveals that more technological progress is necessary for using SSOP with an SPC in real time. Using the current technology (20-kHz DMD), 520-ms acquisition time is obtained at 99% compression rate when a scientific CMOS camera can reach up to 200 frames per second (i.e., 5-ms acquisition time), nearly a 100-fold difference.…”

“…29 This range of spatial frequencies was chosen for investigating the trade-off between compression ratio and image quality, in the context of SSOP-SPC. 30 Then, we compressed a single-phase image from the set of images acquired with SFDI to simulate the acquisition of a single SSOP image by an SPC, with increasing compression ratios of 0%, 50%, 90%, 98%, 99%, and 99.5% using the adaptive basic scan described above with N ¼ 1024. The resulting images are shown in Fig.…”

Spatial frequency domain imaging in 2019: principles, applications, and perspectives

“…28,29 However, recent work on improving processing and filtration in the spatial frequency domain has demonstrated significant image quality improvement making such a method viable for clinical use. 32…”

Real-time optical properties and oxygenation imaging using custom parallel processing in the spatial frequency domain

“…To overcome this limitation, we first introduced Single Snapshot of Optical Properties (SSOP), a specific SFDI method allowing to extract optical properties from a single acquired image in real-time at the cost of image degradation [16,17]. More recent work optimized SSOP acquisition and processing to improve imaging quality and significantly reduced the amount of artifacts from a single phase measurement [18]. However, while only a single image was necessary for extracting optical properties at a single wavelength, multispectral acquisition were performed by using a wheel filter, a tunable filter, or a multispectral camera with sequential acquisitions to distinguish each wavelength [19][20][21].…”