Experimental Study on Realtime Object Tracking Stystem

(1)光流场的快速可靠提取在每个位置，由多个约束方程计算流矢量及其不确定性度量，这些约束方程是通过将连续的输入图像与一组方向选择性空间滤波器进行卷积而获得的。(2)基于光流的目标跟踪算法通过更新矩形窗口来跟踪具有相似光流矢量的目标区域。在多对象跟踪中，跟踪窗口被分配给每个对象。当两个对象重叠时，通过比较重叠区域中的流与每个窗口中的流来确定前景对象。我们还开发了一种方法，通过整合空间和时间上的信息来跟踪复杂背景中的目标。(3)基于光流场和边缘的目标跟踪算法首先从光流场中得到目标的运动边界，然后在边界附近搜索目标的边缘。通过累积提取的边缘来增量地获得对象的整个轮廓。当两个运动相似的物体重叠时，通过比较预测的对比度和实际的对比度来确定前景物体。(4)基于光流和视差的目标跟踪视差是以一对立体图像之间的光流计算的。使用光流、视差和预测的目标位置，通过贝叶斯推断来提取对象区域。该方法可以跟踪对象，即使单独使用流矢量或视差的跟踪可能失败。(5)实时跟踪系统的研制实验跟踪系统由基于DSP的实时图像处理器和主动式立体摄像头组成。该图像处理器包含多个并行工作的DSP板，能够以接近帧速率进行复杂的图像处理。我们成功地使用该系统进行实时目标跟踪。

(1) Fast and Reliable Extraction of Optical FlowAt every location, a flow vactor and its uncertainy measure are calculated from multiple constraint equations, which are obtained by convolving consecutive input images with a set of orientation-selective spatial filters.(2) Object Tracking Based on Optical FlowAn object is tracked by updating a rectangular window circumscribing the object region which has similar flow vectors. In multiple object tracking, a tracking window is assigned to each object. When two objects overlap, the foreground object is determined by comparing the flow in the overlapping region with that in each window. We also developed a method to track an object in a complicated background by integrating information over space and time.(3) Object Tracking Based on Optical Flow and EdgesEdges of an object are searched for around the object's motion boundary obtained from optical flow. The whole contour of the object is incrementally obtained by accumulating extracted edges. When two objects with similar motion overlap, the foreground object is determined by comparing the predicted contrours and the actual controur.(4) Object Tracking Based on Optical Flow and DisparityDisparity is calculated as optical flow between a pair of stereo images. An object region is extracted by Baysian inference using optical flow, disparity, and the predicted target location. The method can track an object even if the tracking with either flow vectors or disparities alone may fail.(5) Development of Realtime Tracking SystemAn experimental tracking system is composed of a DSP-based realtime image processor and an active stereo camera head. The image processor, which contains multiple DSP boards working in parallel, enables complex image processing in nearly a frame rate. We succeeded in realtime object tracking using the system.