Algorithms for image reconstruction after nonuniform sampling

Even though the digitization of astronomical plates is usually performed by means of extremely accurate equipment, some irregularities of the sampling grid, due to the mechanical scanning system, are however unavoidable and can be easily seen in the digitized image. The aim of this paper is to analyze viable techniques to measure those irregularities and to correct, or at least to regularize, the sampling grid. Some practical results show that the proposed algorithms are very effective and that the quality of the data can be substantially improved.