Optical tracking and motion detection using photorefractive Bi12SiO20

Nonlinear grating interaction in photorefractive Bi12SiO20

Optical limiters using photorefractive nonlinearities

The ability of photorefractive crystals such as barium titanate and strontium barium niobate to record spatially phase shifted real time holograms with high diffraction efficiency is the basis of many new optical devices involving coherent amplification. Some examples are unidirectional ring resonators, passive phase conjugate mirrors and coherent image amplifiers. 1 While in the past, most att...

Object Tracking Using Motion Direction Detection

We present an algorithm for tracking objects in a video sequence, based on a novel approach for motion detection. We do not estimate the velocity eld. Instead we detect only the direction of motion at edge points and thus isolate sets of points which are moving coherently. We use a Hausdor distance based matching algorithm to match point sets in local neighborhood and thus track objects in a vi...

Real-time respiratory motion detection with optical patient tracking method

Stereotactic navigation is usually based on rigid registration of the intraoperative situation with preoperatively acquired images. Under this assumption, soft tissue deformation and patient motion will affect the guidance information provided by optical navigation system and can add significant inaccuracy depending on the amount of target motion relative to the initial scenario from pre-operat...

Applying mean shift and motion detection approaches to hand tracking in sign language

Hand gesture recognition is very important to communicate in sign language. In this paper, an effective object tracking and hand gesture recognition method is proposed. This method is combination of two well-known approaches, the mean shift and the motion detection algorithm. The mean shift algorithm can track objects based on the color, then when hand passes the face occlusion happens. Several...