Abstract
Strain measurement method in the whole view field using speckle pattern is summarized in this paper. Advantage of the method using random pattern is that it is not necessary to use grid with regular pattern on the object surface. Disadvantage is that it is not easy to adjust accuracy of the measurement for various sizes of the random pattern and much calculation amount is required for correlation method. But CPU power has been raised rapidly these days and is overcoming this disadvantage. And also the resolution of CCD devices has increased recently. These progresses of technology in CPU and image capture devices realize remarkable progress in the strain field measurement using random pattern.
