Two-dimensional image reconstruction from projections is a well known research field with different applications and using different sources, e.g., varying from medical imaging to a synchrotron laboratory. In the mathematical sense, we are looking for a two dimensional piecewise function with compact support for which a set of signals -the measurements, so called projections or sinograms -are known a priori. After solving the corresponding inverse problem using an appropriate numerical scheme, a collection of reconstructed (gray-scale) images are provided for the final user for further analysis. In practice, the sinogram is often affected by various source of noise which lead to artefacts in the reconstructed images.In this paper, we first convert the resulting gray-scale image that can be viewed as an L-fuzzy set, where L is a finite chain, into an interval-valued image whose values are non-empty, closed intervals of L, so as to express the uncertainty about its values. Subsequently, we apply four approaches of morphological image segmentation, all of which make use of the interval values of the image. Each of these approaches employs some type of morphological gradient and the watershed algorithm. We only consider transmission sinograms for this paper, as emission problems are beyond the scope of this paper.