Coughlan James, Manduchi Roberto
The Smith-Kettlewell Eye Research Institute San Francisco, California 94115, USA
Int J Artif Intell Tools. 2009 Jun 1;18(3):379-397. doi: 10.1142/S0218213009000196.
We describe a wayfinding system for blind and visually impaired persons that uses a camera phone to determine the user's location with respect to color markers, posted at locations of interest (such as offices), which are automatically detected by the phone. The color marker signs are specially designed to be detected in real time in cluttered environments using computer vision software running on the phone; a novel segmentation algorithm quickly locates the borders of the color marker in each image, which allows the system to calculate how far the marker is from the phone. We present a model of how the user's scanning strategy (i.e. how he/she pans the phone left and right to find color markers) affects the system's ability to detect color markers given the limitations imposed by motion blur, which is always a possibility whenever a camera is in motion. Finally, we describe experiments with our system tested by blind and visually impaired volunteers, demonstrating their ability to reliably use the system to find locations designated by color markers in a variety of indoor and outdoor environments, and elucidating which search strategies were most effective for users.
我们描述了一种适用于盲人和视力受损者的寻路系统，该系统使用拍照手机来确定用户相对于张贴在感兴趣地点（如办公室）的彩色标记的位置，手机会自动检测这些标记。彩色标记牌经过特殊设计，可利用手机上运行的计算机视觉软件在杂乱环境中实时检测；一种新颖的分割算法能快速定位每个图像中彩色标记的边界，这使系统能够计算标记与手机的距离。我们提出了一个模型，说明用户的扫描策略（即他/她如何左右平移手机以找到彩色标记）在存在运动模糊限制的情况下（只要相机处于运动状态，运动模糊就总是有可能出现）对系统检测彩色标记能力的影响。最后，我们描述了由盲人和视力受损志愿者测试我们系统的实验，展示了他们可靠地使用该系统在各种室内和室外环境中找到由彩色标记指定位置的能力，并阐明了哪些搜索策略对用户最有效。
