Comments on “The Discrete Periodic Radon Transform”

In the above paper, the new discrete periodic Radon transform was proposed. We would like to prove that this transform was published earlier by Artyom Grigoryan in 1984 and 1986 in the USSR and was known as the tensor, or vector transform. The applications of the tensor and more advanced, paired transforms for image reconstruction of discrete images were also described by Artyom and Merughan Grigoryan in many publications from 1986 through 1990 and later. The paired transform was introduced as an orthogonal 2-D discrete transform which was completely defined by the direction binary functions. The paired transform showed a way of collecting the discrete linear integrals (or projection data) to compose the unitary 2-D transform and reconstruct the image.