Real-time finger-controlled navigation system using laser speckle patterns

We used the invariance of moving laser speckle patterns to develop a finger-controlled navigation system. Laser speckle images were captured using a commercially available image sensor. The relationships between template image size, available movement range, and a maximum correlation coefficient were derived. An essential criterion for setting the correlation coefficient threshold value was determined, and a displacement estimation algorithm was developed. A navigation system test platform and an accuracy analysis program were developed to monitor system performance related to variations in the template image size and the correlation threshold value. The experimental results suggest that the proposed design would be suitable to guide further development of finger-controlled navigation systems using laser speckle patterns.