1. A method of detecting motion, the method comprising: generating a time domain matrix comprising vectors corresponding to variation of pixel values as elements of the time domain matrix, of a video image comprising a plurality of frames; generating a motion matrix from which a low frequency area of the video image is removed by multiplying the time domain matrix by a low rank matrix; and generating a result image comprising a plurality of frames in which vectors, which are elements of the motion matrix, are included as variation of motion pixel values.