Tyrrell James Alexander, LaPre Justin M, Carothers Christopher D, Roysam Badrinath, Stewart Charles V
Rensselaer Polytechnic Institute, Troy, NY 12180-3590, USA.
IEEE Trans Inf Technol Biomed. 2004 Jun;8(2):142-53. doi: 10.1109/titb.2004.828883.
This paper addresses the problem of migrating large and complex computer vision code bases that have been developed off-line, into efficient real-time implementations avoiding the need for rewriting the software, and the associated costs. Creative linking strategies based on Linux loadable kernel modules are presented to create a simultaneous realization of real-time and off-line frame rate computer vision systems from a single code base. In this approach, systemic predictability is achieved by inserting time-critical components of a user-level executable directly into the kernel as a virtual device driver. This effectively emulates a single process space model that is nonpreemptable, nonpageable, and that has direct access to a powerful set of system-level services. This overall approach is shown to provide the basis for building a predictable frame-rate vision system using commercial off-the-shelf hardware and a standard uniprocessor Linux operating system. Experiments on a frame-rate vision system designed for computer-assisted laser retinal surgery show that this method reduces the variance of observed per-frame central processing unit cycle counts by two orders of magnitude. The conclusion is that when predictable application algorithms are used, it is possible to efficiently migrate to a predictable frame-rate computer vision system.
本文探讨了将已离线开发的大型复杂计算机视觉代码库迁移到高效实时实现中的问题,避免了重写软件及其相关成本。提出了基于Linux可加载内核模块的创新性链接策略,以便从单个代码库同时实现实时和离线帧率的计算机视觉系统。在这种方法中,通过将用户级可执行文件的时间关键组件直接作为虚拟设备驱动程序插入内核来实现系统可预测性。这有效地模拟了一个不可抢占、不可分页且可直接访问强大的系统级服务集的单进程空间模型。结果表明,这种总体方法为使用商用现货硬件和标准单处理器Linux操作系统构建可预测帧率视觉系统提供了基础。在为计算机辅助激光视网膜手术设计的帧率视觉系统上进行的实验表明,该方法将观察到的每帧中央处理器周期计数的方差降低了两个数量级。结论是,当使用可预测的应用算法时,有可能高效地迁移到可预测帧率的计算机视觉系统。