Abstract: First of all, this invention relates to a process based on the comparison of the image of a reference object I.sub.ref with the image of an object to be inspected I.sub.exa. Images I.sub.ref and I.sub.exa are picked-up, sampled, discretized and thresheld to produce electronic or binary images I.sub.REF and I.sub.EXA, respectively. These images are cleaned, then centered, I.sub.REF is adjusted to the minimum dimensional tolerances and becomes (I.sub.REF).sub.min. For each image point (pixel), the adjustment is performed by using a structuring element of variable size, the size of which is controlled by a bus from the data contained in a memory unit which take the location of the pixel on the reference object, into account. (I.sub.REF).sub.min is compared to I.sub.EXA which ensures the following function:[(I.sub.REF).sub.min OR I.sub.EXA ]EXCL. OR I.sub.EXA.The resulting image is the image of the "lack" type defects (which does not appear in I.sub.exa with respect to I.sub.ref).