An x-ray computed tomography system, method, and computer product that generates an x-ray beam with an x-ray generator and detects with an x-ray detector at least one characteristic of the x-ray beam generated by the x-ray generator, after the x-ray beam has passed through an object, the system including a converting unit configured to obtain analog projection data outputted by the x-ray detector and to convert the analog projection data to digital projection data, and a processing unit configured to obtain the digital projection data from the converting unit, to detect overflow digital projection data that overflows a measuring range of the computed tomography system, and to correct the overflow digital projection data of the digital projection data by using a curve fitting function.