Determination of the chronological sequence of heterogeneous crossing lines by means of a reverse engineering process

The laser profilometry technique can be used to determine the relative chronology or sequence of intersecting lines. With this type of analysis, firstly the questioned document is inspected in any intersecting area that can potentially be sequenced. Subsequently, a cloud of points, representative of the examined area, is obtained. By means of a CAD program, this cloud of points is transformed into a virtual three-dimensional representation of the paper surface. Unfortunately, often the feature characteristics of stroke intersections are comparable with the natural irregularities of the paper surface. In these cases, the virtual representation (with artificial point of view, lights and texture) cannot be impressive. A non-optimal choice of the point of view, lights and texture can lead to wrong interpretations. The problem can be solved by means of a reverse engineering process, realizing a physical replica of the paper surface. The purpose of this work is to show that the technique of reverse engineering can be useful in the line-crossing problems. Besides, it shows that the physical replica has the same informative content as the original data. In other words, the process of reverse engineering does not introduce undesirable features or destroy important characteristics.