This is an encouraging first result from some playing around I've done with DTW. I modified Jin's DTW MATLAB code to calculate the difference matrix as the Euclidean distance at each point in 3D between the two input data sets. The graph above shows a histogram of the results when 10 recorded actions from task 1 are compared to 10 actions from task 1 (blue), task 2(red) and task 3(green).What does this means? The histogram is of the 'dist' return value, which is a measure of similarity. So when comparing task 1 actions to task 1 actions all of the scores are below 65. When comparing task 1 to task 2 all of the scores are above 72. Similarly, task 1 and task 3 separate fairly well too. In short, it appears DTW can be used as a good similarity measure between like tasks, with lower scores being better.
Another way to look at it is to compare the peaks in the histogram. A task 1 to task 1 comparison will generally score about 50-60, while a task 1 to task 2 will generally score about 90-100
ReplyDelete