Abstract: Labelled bottles are inspected by illuminating the labelled surface and generating brightness or intensity level signals for a plurality of points on the surface with a photo-sensitive diode array. Each intensity level signal is compared with a stored maximum intensity level and a stored minimum intensity level for the corresponding point. A difference signal is generated if the intensity level is greater than the maximum or less than the minimum intensity level. The difference signals are then weighted and summed to generate a figure of merit for the bottle being inspected. The figure of merit is compared with a predetermined value representing a "good" bottle in order to reject "bad" bottles. The maximum and minimum intensity levels can be generated by passing a plurality of known "good" bottles through the apparatus with labels distributed about the edges of the desired label area.