A Method of Collecting All Surface Images of Spherical Materials Using Concave Mirror

Abstract

The invention relates to a method for collecting surface images of spherical materials, in particular to a method for collecting images of the entire surface of spherical materials by using a mirror, and belongs to the technical category of machine vision sorting. It is fast and convenient to obtain a full-surface image of a spherical material through a single camera imaging. In the resulting collection image composed of a front image (4) and three back images (5) that are closely arrayed around the front image, each back image (5) is tangent to the front image (4), and the front The diameter of the image (4) is the same as the size of each back image (5) in its radial direction, which reduces the amount of scale conversion processing. Select a critical value for the aperture of the concave mirror to reduce invalid background segmentation. The imaging background facing the camera and the area that is easily reflected by the concave mirror and enters the camera except for spherical materials are all arranged in black to reduce invalid background segmentation. In the collected collective images, the back image is tightly arrayed around the front image, so that the effective pixels in each image are concentrated, and the area of ​​the CCD photosensitive device is fully utilized to improve the pixel utilization rate.

Description

technical field [0001] The invention relates to a method for collecting surface images of spherical materials, in particular to a method for acquiring all surface images of spherical materials by using a reflector, which belongs to the category of machine vision sorting technology. Background technique [0002] When machine vision sorting, it is often based on material surface information, and the surface information is mainly based on image information. When screening a large number of materials one by one, quickly obtaining all the real images of the material surface is the key to achieve online and accurate sorting. [0003] When the material is spherical or quasi-spherical, limited by the curved surface, multiple images can cover the entire surface of the material through multiple or multi-view imaging, but the limited image theoretically exists for the local features on the surface of the spherical material. a certain degree of distortion. In order to obtain the surfa...

AI Technical Summary

Problems solved by technology

Restricted by the optical characteristics of the flat mirror, there are size changes between the reflected image and the front image, especially when this technology is applied to spherical materials, the three images cannot cover the entire spherical surface, resulting in missed sampling

Compared with the plane reflector, the parabolic reflector can obtain the back image of the spherical material, and has the effect of magnifying the reflected image. However, when the magnification ratio is not controlled, the surface image processing involves complex data conversion, resulting in a large amount of calculation. long data processing time

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