| 摘要 |
The invention relates to an in-line optical method of inspecting transparent or translucent containers (3) travelling between a light source (7) and a system (9) for taking images of the containers and analysing the images taken. According to the invention, the method comprises the steps of: illuminating each container (3) using the light source (7) having a light intensity variation according to a periodic pattern (71) of period T1 along at least one first direction of variation (D); for each container (3), taking a number of images N, greater than or equal to three, of the container passing in front of the light source and occupying respectively N different positions along the length of the path; between each image capture, creating a relative shift between the container and the periodic pattern according to a direction of variation (D) of the periodic pattern (71); determining and applying a geometric transformation in at least N-1 images of a single container for at least one set of points belonging to the container, in order to align the pixels belonging to the container in the N successive images of a single container; for each container (3), constructing a phase image from the N adjusted images of the container; and analysing the phase image in order to deduce therefrom at least the presence of a light-refracting defect or the distribution quality of the material forming the container. |
