Calculate the distance between each crack through a reference point

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I am doing a project where I have to get the coordinates of each cack detected through a respected axis. I have used the euclidean distance calculation of each contour from the left most edge of the video to the centroid crack and each crack detected in order to get a store the coordinates. Right now the coordinated are moving because it is detecting the coordinates of the camera instead of the bridge. Do you have any approaches on how to get the distance between the cracks without getting the coordinates of the camera.