Since backlighting is a problem on most conveyors then using a structured light may be the solution.

In general, arbitrary lighting of the environment is not acceptable because it can result in low-contrast images, specular reflections, shadowing, and extraneous details. A well-designed lighting system illuminates the scene so that the complexity of the resulting image is minimized, while the information required for inspection or manipulation is enhanced.Once the data of the scene is in memory, further algorithms can be employed to extract useful feature data, such as: modeling the algorithm of an object to extract the following features: area, parameters, centroid, ratio of minimum to maximum moment of inertia, axis of least moment of intertia, diagonal length of a bonding rectangle, and simple dimensional measurements at key points that can resolve a problem.