Existing sinogram restoration methods cannot handle noises and nonstationary artifacts simultaneously. Although bilateral filter provides an efficient way to preserve image details while denoising, its performance in sinogram restoration for low-dosed X-ray computed tomography LDCT is unsatisfied. The main reason for this situation is that the range filter of the bilateral filter measures simil...

We discuss data filtering prior to image reconstruction. For this kind of filtering, the radial direction of the sinogram is routinely employed. Recently, we have introduced an alternative approach to sinogram data processing, exploiting the angular information in a novel way. This new stackgram representation can be regarded as an intermediate form of the sinogram and image domains. In this ex...

We describe lossless methods for compression of 3D PET data. Static list-mode data is re-sorted into sinograms and compressed using a combination of run-length and entropic coding. Dynamic list-mode data is compressed using a sinogram/timogram format in which the arrival times of each photon pair are stored in spatial order, indexed by the sinogram. Compression of the timogram is performed usin...

We describe two approaches to lossless compression of dynamic PET data. In the first, a sequence of sinogram frames are compressed using differential encoding followed by lossless entropy-based compression. The second approach applies lossless compression to data stored in a sinogram/timogram format in which the arrival times of each photon pair are stored in spatial order, indexed by the sinog...

A sinogram is image representation of raw data obtained from projections of the object for image reconstruction. Radial sinogram domain filtering, i.e. filtering along the projections of the sinogram, is a common noise reduction technique for the data. The stackgram domain, in which the signals along the sinusoidal trajectories of the sinogram can be processed separately, is a new method for si...

Seeking for quantitative tomographic images, it is of utmost importance to limit reconstruction artifacts. Detector imperfections, inhomogeneity of the incident beam, as classically observed in synchrotron beamlines, and their variations in time are a major cause of reconstruction bias such as `ring artifacts'. The present study aims at proposing a faithful estimate of the incident beam local i...

In this paper we propose a new approach of tomographic image reconstruction using sinogram interpolation for a sparse projection data. In this term, sinogram interpolation is a process of converting a sampled projection to a higher sampling rate projection. By using interpolation, we construct a new projections within the range of set of projection, then we apply a filtered backprojection recon...

In X-ray computed tomography (CT), the presence of metal objects in a patient's body produces streak artifacts in the reconstructed images. During the past decades, many different methods were proposed for the reduction or elimination of the streaking artifacts. When scanning a patient, the projection data affected by metal objects (missing projections) appear as regions with high intensities i...

In this paper, we extend a multiscale Bayesian approach to modeling and estimation of general Poisson processes previously developed in [1] by the first two authors, and apply it to the emission computed tomography (ECT) image reconstruction problem. We develop a practical prior model for the sinogram image, which we use to estimate the underlying sinogram intensity from the raw projection data...