Method for sensing motion and device for implementing the same

A method for sensing a motion of an object is to be implemented by a motion recognition device that includes an image acquiring unit and a processor. In the method, the image acquiring unit is configured to acquire a series of image frames by detecting intensity of light received thereby. The processor is configured to receive at least one of the image frames and to determine whether an object is detected in the at least one of the image frames. When an object is detected, the processor is further configured to receive the image frames from the image acquiring unit, and to determine a motion of the object with respect to a three-dimensional coordinate system according to the image frames thus received.