Two types of angular rotation deviations are observed in our optical CT scanner for gel dosimetry: a large deviation at the starting position, and small deviations during the scanning. In order to investigate the influence of these angular rotation deviations on the reconstructed OD maps, we applied the angular deviations on a synthetic phantom for optical CT simulation. Meanwhile, three recons...

In this paper a method for digitally recording four quarter-reference-wave-holograms (by CCD) in a Mach-Zehnder interferometer setup, and reconstructing the object wave-front by numerical method is presented. The terms of direct transmission, auto-correlation and conjugate wave in the four wave reconstruction are cancelled out and only one original object wave is left after overlapping. Reconst...

A fully non-contact CCD-based approach to sub-surface fluorescence diffuse optical imaging is presented. An overview of CCD-noise sources are described and a possible solution for obtaining an adequate SNR in CCD-based diffuse optical imaging is implemented. To examine the impact of excitation and remission light attenuation in this geometry, the linearity of response in recovering object posit...

Recently, a number of approaches to low-dose computed tomography (CT) have been developed and deployed in commercialized CT scanners. Tube current reduction is perhaps the most actively explored technology with advanced image reconstruction algorithms. Sparse data sampling is another viable option to the low-dose CT, and sparse-view CT has been particularly of interest among the researchers in ...

Iterative Algorithms can obtain good reconstruction image for enough Iterative times in the technique ct image reconstruction. The order method of the Weighted Distance Orthogonal (WDO) is introduced in this paper to accelerate the Iterative reconstruction, which improves greatly the access mode of ART to projection data, based on the crucial effect that the access order of projection date has ...

The use of higher order approximations to the Radiative transport equation, through simplified spherical harmonics expansion (SPN) in optical tomography are presented. At higher orders, the image reconstruction becomes highly under-determined due to the large increase in the number of unknowns which cannot be adequately recovered. However, reconstruction of diffuse parameters, namely optical ab...

Quantitative 3D phase retrieval techniques are based on either interferometric techniques such as holography or noninterferometric intensity-based techniques such as the transport of intensity equation (TIE). Interferometric techniques are vibration-sensitive and often use a reference beam requiring complicated optical alignment. In this work we develop a simple, fast, and noninterferometric to...

We deal with the reconstruction of the high-resolution (HR) computed tomography (CT) image from the CT projection data (Sinogram). Spatial resolution is one of the important parameters of CT images. Spatial resolution is a measure of how close to each other two objects that can still be distinguished. The spatial resolution of CT images depends on the field of view which in turn depends on the ...