System object: vision.BlockMatcher
Compute motion of input image
V = step(H,I)
C = step(H,I)
Y = step(H,I,IREF)
V = step(H,I) computes the motion of input image I from one video frame to another, and returns V as a matrix of velocity magnitudes.
C = step(H,I) computes the motion of input image I from one video frame to another, and returns C as a complex matrix of horizontal and vertical components, when you set the OutputValue property to Horizontal and vertical components in complex form.
Y = step(H,I,IREF) computes the motion between input image I and reference image IREF when you set the ReferenceFrameSource property to Input port.
Note: The object performs an initialization the first time the step method is executed. This initialization locks nontunable properties and input specifications, such as dimensions, complexity, and data type of the input data. If you change a nontunable property or an input specification, the System object™ issues an error. To change nontunable properties or inputs, you must first call the release method to unlock the object.