Abstract: This paper presents theoretical description for digital speckle correlation methodwhich is based on variational and image recognition principle。The problem of deformationmeasurement is then converted into a pure numerical computation, in which the difficultiesdue to interferometric fringes in conventional optical methods can be avoided.Primaryexperiments indicated that the method can be applied in engineering environments,andis capable of measuring deformations quantitatively in high speed dynamic process a...