We optimize the layout of each light plane in a dual-view multistripe measurement system by employing spatial geometry analysis to avoid ambiguity. The imaging regions of every light plane can be labeled uniquely on two image planes within a certain measurement depth. Moreover, the flexible density of fringe patterns corresponding to the different measurement depths is immediately projected without the conventional coding procedure. Some experiments verify the effectiveness of the proposed method applied in high-resolution 3-D measurements.
In this paper, a structured light system based on synchronous scanning technology is developed for meeting the need of body surface acquisition. The proposed system is composed of a
fixed CCD camera, a fixed structured light projector and a mirror scanner. While the mirror is reflecting light stripes and scene images, the camera acquires a series of body section images from the scanner. After extracting the trace of laser stripes and calculating the relative 3-D coordinate of the illuminated pixels on the series of CCD images, the system can acquire the spatial profile of the
inspected body surface. Moreover, a prototype is developed according to the results from geometrical analysis mentioned above. The experiment data obtained from the scanning system are shown. This synchronized scanning system can be widely applied in the custom design, surgery navigation and the other optical measurement field in the future.
This paper presents a novel method for speckle reduction in ultrasonic images. Firstly, a particular filtering kernel is defined by decomposing the local rectangular neighborhood into asymmetric sticks pointing outside with variable orientation from the investigated pixel. Then the local mean and variance along each stick are calculated using a template based convolution algorithm. Finally, a pseudo-diffusion model is derived to diffuse the intensity averages of sticks into the central pixel, and a variance sensitive conductance functions is designed to adaptively control the diffusion strength in varying directions. The proposed method is in essence an integration of the linear boundary detection operator, i.e. stick technique, and the nonlinear diffusion model. In homogeneous regions, our method will act as a Gaussian like low pass filter, since the sticks are partially overlapped near the center, which implicitly assigns distance dependent weights to neighboring pixels. In heterogeneous regions, the information is expressed as many structures, which often occur as line boundaries or tube shapes in ultrasonic images, then our approach can encourage smoothing along the sticks falling inside the structures, and penalize blurring along the sticks across edges. The performance of our method is verified in experiments of both synthetic and clinical ultrasonic images. The results show that our method outperforms the existed filtering techniques in term of smoothing homogeneous regions, preserving resolvable features, enhancing weak edges and linear structures.
A laser profiler in machine vision integrated sensor that scans the inspected object's surface by the rotation of the structured light is designed based on the optical triangulation. The system parameters have been optimized for a harmonious arrangement among the range resolution, the measuring accuracy and the shadow effects. The point-to-point mapping relationship among the 2D images and 3D surfaces from the different views and orientations can be developed by means of the spatial geometric correspondence. Moreover, the intensity, color and texture information from CCD images can be affixed to the entire 3D surface. As a result, near range data fusion in machine vision integrated sensor can be realized.
The design of a two-dimensional x-y scanner for an integrated machine vision sensor, which innovates a synchronized spot scanning triangulation imaging system for precision data within the near range and a laser radar (lidar) to get the coarse image at the far field, is discussed in this paper. To support the new idea of layer and modular structure of machine vision structure, the two set of imaging systems have in common with the same scanner for emitting and returning optics with one laser source, to ensure that the data from two imaging systems respectively are coordinated in time and space. After expounding the basic principle of laser triangulation range imaging system based on synchronized scanner, system parameters involving the optics, the electronics are determined according to the active range, image resolution, frame frequency, and the range accuracy.
In this paper, a real-time eye tracking technology for the adaptive human-computer interaction has been introduced. The principle of system adaptability is presented, and the system architecture is also described. The adaptive system can segment the interesting eyes' area in jittering images through utilizing the digital image processing technologies, which involve image filter, edge enhance, feature extraction et al. Then, the ideal detection algorithm for the eye-gazing direction is put forward, and the revising approach for the head slight movement is given which can calculate relative position deviation between the Purkinje image and the pupil. The system can accurately distinguish among as many as nine dialog boxes arranged in a 3x3 matrix on the display screen. At the same time, the manipulation ofperipheral equipment based on this kind ofinterface through eye-gaze is discussed. The results of the experiments have been given. The system will be used widely for disabled people.
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