Abstract: In analysing the weldment radiography,the authors,applying the theory of randomprocess,stochastic geometry,optical imaging,and signal processing,took the Mod-estino-Fries’ model and introduced the concept of stochasties and a digital processingmethod,named stochastic homomorphic filtering,into the enhancement of such images.Some satisfactory results,which would be much more difficult for those simplespatial-domain processing methods,were obtained.This thesis provides a new approachto the methematical model and processing method for practical weldment radiography.