Synthesized Images for Pavement Management System Design

Abstract

In visual pattern recognition, since it is generally difficult to obtain images with all the desired characteristics, researchers often reuse standard test images obtained under fixed conditions. This practice may compromise the investigation because existing images may need major changes in optical parameters (camera position and orientation, illumination conditions, relative position of objects, etc.) or the original scene may be unavailable. It is well known that most engineering algorithms can only work well under certain conditions. In the development of novel algorithms, we might require specifications not fully met by the existing data (patterns). “Synthesized patterns,” in which a computer meets these requirements, may be the solution to the problem, due to its advantages of low cost, easy specification, independence from environmental conditions, and realistic visualization of abstract ideas that stimulates creativity. We can use “ray tracing,” a computer graphics technique with optical correctness requiring a few numerical parameters, to create a scene. The results are presented in the format of light intensity maps, convenient for pattern recognition algorithms. Once the algorithms under study are verified with the synthesized images, we can specify the conditions for acquiring real-world images, thus reducing costly trial-and-error procedures. This paper proposes a novel approach to generate cracks and potholes using “fractals” with “texture mapping.” The results demonstrate the usefulness of the proposed approach in the design and implementation of pavement management systems.