1. A process for the automatic detection of defects in a mechanical part of complex geometry from a radioscopic image of said part having zones bereft of useful data, referred to as non-assessable zones, within assessable zones, comprising: producing at least one radioscopic image of the mechanical part to be inspected; segmenting said radioscopic image into two classes of zones corresponding respectively to said assessable zones and said non-assessable zones in order to obtain a bi-phase radioscopic image in which different values of gray levels represent the assessable zones and the non-assessable zones and processing said values of gray levels to obtain a binary image referred to as a mask; choosing a standard formative element of predetermined size and shape; calculating the intersection of said standard formative element with said mask; modifying the standard formative element based on the calculated intersection of said standard formative element with said mask to generate a modified formative element; defining conditional morphological transformations using said modified formative element; and applying said conditional morphological transformations to said bi-phase radioscopic image in such a way as to show possible defects in the assessable zones.