Method for determining markings in relief on the outer surface of the sidewall of a tyre
用于确定轮胎的侧壁的外表面上的浮雕般的标记的方法
Résumé
The invention relates to a method for extracting marking patterns in relief on the surface of the sidewall of a tyre, comprising steps wherein: the three-dimensional image of said surface of the sidewall is captured by associating, with each pixel of the image, a greyscale value proportional to the elevation of said point in relation to said surface, in order to obtain a starting image (f); a series of successive morphological openings of the image of the starting surface (I), (II) and (III) are carried out iteratively by means of linear structuring elements of successively increasing sizes, oriented in the circumferential direction; the value of an image obtained after morphological opening with a structural element is subtracted from the value of the image obtained after morphological opening by means of the structuring element of an immediately smaller size (IV) and (V) in such a way as to obtain a succession of images flattened by the difference, initialising the procedure by the subtraction of the image obtained by means of the smaller-size structuring element from the starting image (f); a thresholding of the images flattened by the difference is carried out in order to obtain binary images (VI), (VII) and (VIII); and a set union is made of the values of each of the binary images to obtain a final binary image wherein only the marking patterns appear in relief (IX).
一种轮胎侧壁表面上具有的浮雕标记图案的提取方法，包括步骤：捕获侧壁表面的三维图像，同时对图像的每一个像素赋予与此点相对于所述表面的升高成比例的灰度值，以获得起始图像；借助于具有相继增大的尺寸且沿圆周方向取向的线性结构元素，以迭代方式执行起始表面的图像的一系列相继的形态学开；从形态学开之后获得的图像的值减去借助于紧随的较小尺寸的结构元素的形态学开之后获得的图像的值，以获得一连串通过差分化变平的图像，同时通过从起始图像减去借助于具有较小尺寸的结构元素获得的图像来初始化程序；执行变平的图像的阈值化，以获得二值图像；实施各二值图像的值的集理论合并，以获得最终二值图像，其中仅标记图案浮雕般地显现。