Vibration frequency measurement by video

I have a robot that uses a vibration motor to move forward using the force of vibration. I would like to take video of the leg vibrations and measure the vibration frequency. I think there are three steps: reading the video, extracting information from the frame, and calculating the number of vibrations. I would appreciate it if you could tell me how to input information such as color and shape.

videoFile = 'videoFile.mp4';

v = VideoReader(videoFile);

legPositions = [];

while hasFrame(v)

frame = readFrame(v); % フレームを読み込む

gray = rgb2gray(frame); % RGB画像をグレースケール画像に変換

% 白色の脚に相当するグレースケールの範囲を指定

grayThresholdLow = 200; % グレースケールの下限

grayThresholdHigh = 255; % グレースケールの上限

% グレースケールに基づいて脚の位置を二値化

legMask = (gray > grayThresholdLow) & (gray < grayThresholdHigh);

% 連結成分のラベリングを行い、各オブジェクトを識別

labeledImage = bwlabel(legMask);

% 各オブジェクトの位置（重心）を計算

properties = regionprops(labeledImage, 'Centroid');

centroids = cat(1, properties.Centroid);

legPositions = [legPositions; centroids]; % 脚の位置を保存

end