Camera-based depth estimation methods are useful for various automobile applications. For example, depth estimation methods based on stereo cameras triangulate the depth between objects and cameras. However, they are ...
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Camera-based depth estimation methods are useful for various automobile applications. For example, depth estimation methods based on stereo cameras triangulate the depth between objects and cameras. However, they are ...
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ISBN:
(数字)9798350395914
ISBN:
(纸本)9798350395921
Camera-based depth estimation methods are useful for various automobile applications. For example, depth estimation methods based on stereo cameras triangulate the depth between objects and cameras. However, they are susceptible to baseline distortion owing to vibrations, aging, and thermal expansion. On the contrary, depth estimation methods based on a monocular camera, such as depth-from-defocus, use a focusing mechanism or spectroscopic optics to calculate the depth from the difference of defocus images. However, because the change in sharpness, which is the inverse of defocus, is slightly in the depth direction, it is unsuitable for deep-range estimation. Therefore, we are developing depth-estimation methods that use a monocular camera with special focus images obtained through tilted optics, which have no baseline distortion problem and have a deep estimation range. When tilted optics are used, the plane of sharp focus (POF) appears tilted, while the depth of field (DOF) lies and increases toward the depth direction. Moreover, to allow for the use of only one image-sensor, a one-shot, we studied a depth estimation method using tilted optics with two different aperture sizes for each color wavelength by introducing concentric color filter apertures. However, as with conventional methods, the Gaussian sharpness model does not strictly fit to the actual sharpness, resulting in reduced estimation accuracy. In this study, we propose a method for high-speed and high-accuracy depth estimation that involves adding a split color filter aperture to a tilted optic and using a different sharpness model for each DOF side.
A new procedure for the optimum design of optoelectronic devices is explained in this paper and an automatic search is made simultaneously for the structure satisfying various demands. The feature of this procedure is...
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A new procedure for the optimum design of optoelectronic devices is explained in this paper and an automatic search is made simultaneously for the structure satisfying various demands. The feature of this procedure is in the introduction of cost by which the quantitative evaluation of the structure becomes possible and the global search for the required structure by simulated annealing can be carried out. First, the definition of cost and details of the optimization procedure are clarified. In optimization, in addition to convergence to the minimum point of the cost function (the optimum configuration from theoretical viewpoint), the convergence also is possible in structures with great tolerance to fabrication errors (neighborhood cost (NC) and finite temperature annealing (FTA) methods). Next, these three proposed methods are used in the design of a pnpn differential optical switch and the effectiveness of the methods is verified. The method of cost expression, the relation between annealing parameters, and convergence are investigated. It is shown that cost expression with large degree of freedom improves the search for high-performance structures and the initial temperature of annealing or the fixed temperature of FTA method is the important parameter which sets up the probability of acceptance. Further, it is shown that the convergence cost is inversely proportional to the time spent in annealing. These results are useful guidelines in the optimum design of arbitrary optoelectronic devices.
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