Even when the parameters of the radiographic test are chosen carefully, the images present
problems such as the existence of noise, nonuniform distribution of grays, and deficient
contrast. In this way, when there is a very small defect in the weld bead, it can be confused
with noise existing in the image, whether it originates in the digitization stage or even in the
process of inspection [2].
After digitizing the images, there is the possibility of processing them with the application of
digital image filters, eliminating or smoothing the existence of such problems. It should be
mentioned that the application of the filters must be made carefully so that no relevant
information is lost, which could generate, for example, the underrating of a defect or even its
exclusion from the image.
As will be shown, the processing stage of industrial radiographs is quite complex, and the
diversification of the techniques used is verified in various articles mentioned throughout this
paper.