Multimodal Range Image Segmentation
Michal Haindl, Pavel Zi · 2007
The segmentation process is perhaps the most important step in image analysis since its performance directly affects the performance of the subsequent processing steps in image analysis and it significantly determines the resulting image interpretation.Despite its utmost importance, segmentation still remains as an unsolved problem in the general sense as it lacks a general mathematical theory.The two main difficulties of the segmentation problem are its underconstrained nature and the lack of definition of the "correct" segmentation.Perhaps as a consequence of these shortcomings, a plethora of segmentation algorithms has been proposed in the literature.These algorithms range from simple ad hoc schemes to more sophisticated ones using object and image models.The area of segmentation algorithms typically suffers with the lack of benchmarking results and methodologies.With few rare exceptions in specific narrow applications single segmentation algorithm cannot be ranked and potential user has to experimentally validate several segmentation algorithms for his particular application. Range Image SegmentationRange images store, instead of brightness or colour information, the depth at which the ray associated with each pixel first intersects the object observed by a camera.In a sense, a range image is exactly the desired output of stereo, motion, or other shape-from vision modules.It provides geometric information about the object independent of the position, direction, and intensity of light sources illuminating the scene, or of the reflectance properties of that object.Range image segmentation has been an instrument of computer vision research for nearly 30 years.Over that period several partial results have found its way into many industrial applications such as geometric inspection, reverse engineering or autonomous navigation systems.However similarly as in the spectral image segmentation area the range image segmentation problem is still far from being satisfactory solved.