Compagnie Generale Des Etablissements Michelin

Michelin Recherche Et Technique S.a.

Michelin Recherche Et Techniques S.a.

Yusi Shen

Jean-Paul Zanella

Guillaume Noyel

Claire Moreau

A method for processing an image of a surface of a tire to be inspected is described. A three-dimensional digital image is captured of the surface, and each pixel of a plane of the image is assigned an item of information relating to an elevation of the pixel with respect to the surface. By utilizing of a morphological operator that uses a structuring element, a first transformation of the image of the surface is performed with aid of an opening and then of a closing, so as to tailor a grey level of pixels situated abnormally above or below the surface.

Analysis of the digital image of the external surface of a tyre and processing of false measurement points

A method for processing an image of a surface of a tire under inspection is described. A three-dimensional digital image of the surface is captured and, for each point of the captured image, a grey-level value corresponding to an elevation is assigned to the point. Utilizing a first morphological operator that uses a rectangular key element, a closure-type first transformation of the image of the surface is carried out. Utilizing a second morphological operator that uses a rectangular key element, an opening-type second transformation of the surface is carried out. For each point of the image, a grey-level value equal to a minimum value between a grey-level value at that point obtained in a preceding step and a grey-level value at that point is assigned, so as to eliminate false measurement points.

Analysis of the digital image of the internal surface of a tyre and processing of false measurement points

In a method for processing an image of a surface of a tire, a 3D digital image of the surface is captured, and each pixel of the captured image is assigned a grey level value proportional to an elevation of a corresponding point with respect to the surface. The pixels are placed in rows and columns. A search is made for zones of the surface that include pixels having a grey-level value lower than a given threshold. Boundaries of an encompassing box that includes one or more of the zones are determined. Inside the encompassing box, a grey-level value equal to a mean grey-level value of a set of reference pixels (K, s) positioned in a zone situated in immediate proximity to a pixel under consideration is assigned to each of the pixels whose grey-level value is lower than the given threshold.

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Clermont-Ferrand, France

Yusi Shen