Distance measuring and speed measuring methods and devices based on video images

The invention provides distance measuring and speed measuring methods and devices based on video images. On the premise that a movement track of a measured object is perpendicular to a camera optical axis and the movement track of the measured object is a straight line, when the measured object moves from point A to point B in the movement track, distance between point A' and point B' is measured, wherein the point A' and point B' are corresponding points of the point A and the point B in an image plane. The distance between the point A and the point B is measured, according to the measured distance between the point A' and the point B' and a mapping proportionality coefficient of the distance in the movement track to the corresponding distance in the image plane. By adopting of the methods and the devices, real-time performance and accuracy of the measurement can be improved.