Abstract: A method for detecting low-contrast pressing or blowing defects in glassware articles includes the steps of backlighting the article by way of one or several light sources according to at least one pair of similar patterns shifted in space; capturing at least one pair of images of the backlit article according to each of the patterns of the at least one pair of patterns; combining the images of each of the pairs to form at least one composite image; and detecting the areas of stronger contrast within the composite images.

Abstract: The invention provides a method of optically reading relief carried by the outside wall of a transparent or translucent receptacle. The method of the, invention consists:in illuminating the receptacle by means of an incident light cone supplied by a lighting system placed beneath the receptacle;in adjusting the width of the incident light cone to limit lighting at least to the portion of the outside wall that is provided with relief in order to avoid parasitic reflections;in picking up the reflected light beams by means of the pick-up element disposed beneath the receptacle and suitable for forming a plane image of the wall of the bottle; andin adjusting the field angle of the pick-up element as a function of the characteristics of the receptacle.