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Papermaking process consists in a succession of unit operations that are successively the forming section, the press section and finally the drying section. Forming and pressing are on the scope of this paper as they may influence the aspect of the studied material: paper. The main objective is to characterize paper and more specifically its visual quality, mainly due to marking which consists in successive white and dark strips. A proposed method is described in order to analyze the quality of this visual aspect of paper, which is a very important factor for the consumer. This paper is therefore devoted to the presentation of an industrial tool to Digital Image Processing that allows the evaluation of cigarette paper marking quality. This problem is delicate as different technical and physical parameters have some influence on the paper appearance. For example the whiteness or the opacity of paper influences the evaluation of the quality of the marking. Furthermore, an expert of paper cigarette who observes the paper lying on a black support carries out the classical test of quality evaluation. Thus the reflection of light is mainly observed instead of the look- through aspect. Usually, this determination is made by the experienced eye of the expert who may distinguish between 5 to 6 classes of paper quality. Moreover, sensibility and subjectivity play an important role in this grading establishment. The aim of the presented tool is to obtain an object classification of the paper marking quality. Image analysis is used in order to mimic the expert experience. In a first step, the image acquisition is done using a standard scanner. Then developed software analyzes the obtained image numerically. The sensibility of the image analysis is high, and the results are repeatable. The classification of different cigarette papers using this method provided the same results as the human expert, pointing out the validity of the developed method. Some experimental results are presented in order to illustrate the industrial interest for this method. We present in a first part the new method to obtain an evaluation of the quality of a material property (paper aspect) from image analysis. Then example of measurements obtained on different paper samples, using a classical scanner, illustrate the proposed methodology. Finally, some comparison between the classifications obtained from the proposed method and the human expertise are presented to underline the interest of the proposed objective method.
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