Error analysis for dimensional measurement using computer vision techniques

Computer vision techniques used in performing dimensional measurements are illustrated. In general, it is seen that laser technology is effective in performing precision dimensional measurements as long as the object being measured is properly positioned and lies within a well-defined distance from the receptor. However, installing and operating a laser-based dimensional measuring system is costly. Also, the rate at which intensity and range images are sampled is relatively slow compared to semiconductor imaging devices. On the other hand, charge- coupled-device (CCD) camera have inherent nonlinear photoreceptor transfer characteristics and require computer resources to execute image-processing algorithms. Also, range data must be incorporated in order to perform 3-D as well as 2-D measurements. An analysis of measurement error is presented to relate intensity and range images