Finger Tracking Using Ridge Detection

I developed a video-based finger tracking algorithm with Bas van der Velden. This very simple algorithm exploits the fact that fingertips have the highest "ridges" in videos of hand movements. The results using this code and video are shown below, where the red asterisk marks the estimated index fingertip position.

These three videos can be viewed simultaneously here.

Download Matlab m Files

Download Example Video Frames

Example one-finger search and five-finger search trackings are shown below. The video was collected from below a clear tactile map stimulus, and the image is corrected for perspective transforms, left-right flipped, and cropped to the size of the stimulus. Finger-tracking results are shown in red (one-finger) and red and black (five-finger).

Search Trajectory Simulations

Levy Walk
Brownian Motion

Zig Zag
Parallel Sweeps
Archimedes Spiral
Expanding Square

I created a Matlab program that simulates search trajectories for the search for a target in a bounded area using different strategies. This program simulates search for ballistic motion, Levy walk (accepting any value of mu larger than 1), Brownian motion (Levy with mu larger than 3), parallel sweeps, zig zag, spiral, and expanding square. The function returns the distance traversed by the searcher, and has the option for creating a plot of the trajectory. The function allows for the user to select the detection radius, start location, and target location. Example plots show output plots for a search beginning at the green circle and ending at the red circle (same target in all plots).

Download Matlab m File.

Response Time GUI


This program runs in Matlab, and is useful for extracting response times from audio recordings made during a psychological study.

Download Code

Download Instructions

This program was used in the following publications,
Morash, V., Connell Pensky, A., Tseng, S.T.W., & Miele, J. (2014). Effects of using multiple hands and fingers on haptic performance in individuals who are blind. Perception, 43, 569-588.
Morash, V., Connell Pensky, A., & Miele, J. (2013). Effects of using multiple hands and fingers on haptic performance. Perception, 42, 759-777.