论文标题
基于戴维斯相机事件的寿命,异步角跟踪算法
Asynchronous Corner Tracking Algorithm based on Lifetime of Events for DAVIS Cameras
论文作者
论文摘要
事件摄像机,即动态和主动像素视觉传感器(戴维斯),捕获场景中的强度变化,并以异步方式生成一系列事件。在高动态环境中,此类相机的输出率每秒最多可达到1000万个事件。戴维斯相机使用模仿人眼的新型视觉传感器。它们的吸引人属性,例如高输出速率,高动态范围(HDR)和高像素带宽,使其成为需要高频跟踪的应用的理想解决方案。此外,在具有挑战性的照明方案中运行的应用程序可以利用事件摄像机的高HDR,即140 dB,而传统摄像机的60 dB。在本文中,提出了一种新型异步角跟踪方法,该方法使用戴维斯相机捕获的事件和强度图像。 Harris算法用于提取特征,即来自关键帧的框架角,即强度图像。之后,匹配算法用于从事件流中提取事件角。事件仅用于执行异步跟踪,直到捕获下一个密钥帧为止。在事件角周围的窗口大小的窗口大小中,相邻事件用于通过使用随机的Hough变换算法拟合2D平面来计算提取的事件角的速度和方向。实验评估表明,我们的方法能够在传统摄像机的盲时间(即连续两个强度图像之间)更新提取的拐角的位置,最高100倍。
Event cameras, i.e., the Dynamic and Active-pixel Vision Sensor (DAVIS) ones, capture the intensity changes in the scene and generates a stream of events in an asynchronous fashion. The output rate of such cameras can reach up to 10 million events per second in high dynamic environments. DAVIS cameras use novel vision sensors that mimic human eyes. Their attractive attributes, such as high output rate, High Dynamic Range (HDR), and high pixel bandwidth, make them an ideal solution for applications that require high-frequency tracking. Moreover, applications that operate in challenging lighting scenarios can exploit the high HDR of event cameras, i.e., 140 dB compared to 60 dB of traditional cameras. In this paper, a novel asynchronous corner tracking method is proposed that uses both events and intensity images captured by a DAVIS camera. The Harris algorithm is used to extract features, i.e., frame-corners from keyframes, i.e., intensity images. Afterward, a matching algorithm is used to extract event-corners from the stream of events. Events are solely used to perform asynchronous tracking until the next keyframe is captured. Neighboring events, within a window size of 5x5 pixels around the event-corner, are used to calculate the velocity and direction of extracted event-corners by fitting the 2D planar using a randomized Hough transform algorithm. Experimental evaluation showed that our approach is able to update the location of the extracted corners up to 100 times during the blind time of traditional cameras, i.e., between two consecutive intensity images.