This invention provides a method and computer-readable medium for detecting motion and filtering noise from images. The method includes (a) dividing an incoming image into several blocks; (b) comparing the blocks to the corresponding blocks of a referred image and saving compared results into a declared data structure; (c) marking the compared result that exceeds the first predetermined threshold; (d) grouping the compared result into an adjacent region thereof; and (e) calculating a deviation value of the region and comparing the deviation value to the second predetermined threshold, whereby the motion in images can be detected and the noise caused from moire and the interference resulted from an area brightness variation also can be filtered out. In addition, the amount of operations in comparing images can be reduced as well due to the employment of block processing instead of pixel processing.