Optical computing methods and systems for inspecting a glass container in transmitted light

Abstract

There are provided an optical computing method and system for inspecting in through light a container. The container is illuminated by elementary emitting areas each emitting a polarized emitted light with an emitted polarization property of interest that varies according to a law of periodic variation which, over a primary period, follows a triangular variation as a function of the position of the elementary emitting area along the primary direction. Digital images are acquired, with at least one camera, with interposition of a linear analyzer having a given axis of polarization for a partial digital image. At least one primary raw refraction image is calculated, each pixel of which is representative of the refraction undergone by the light. The system advantageously includes a two-dimensional matrix of liquid crystal cells.