A Comparison of Sinogram and Stackgram Domain Filtering Methods Employing L-Filters for Noise Reduction of Tomographic Data

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 sinogram data filtering. We have shown in our earlier studies the potential of the stackgram domain approach, but not its superiority compared to the other filtering methods. In this study, we compare radial sinogram domain and angular stackgram domain filtering techniques employing nonlinear L-filters. According to our quantitative studies, that are also comparable to our previous studies, stackgram domain filtering provides the best resolution versus noise trade–off for the compared methods. Besides, as noticed in our studies, the noise structure looks visually more pleasant after stackgram filtering, compared to radial filtering.