Vibration from frames

vibration_from_images.m is a function that can be used to extract the frequency of a simple harmonic vertical vibration. The mass has to have a horizontal landmark.
The included video (Video.avi) has been recorded as an illustrative example.
vide02pic.m (shared by Shiquan Wang in Matlab central) was used to extract the individual frames.
Hough_Grd.m(shared by Tao Peng in Matlab central) was used to detect the lines in the image. Only the horizontal lines in the image has been kept(by keeping lines with small slopes).