1. An image processing method capable of detecting noise, comprising: adjusting a lighting unit to acquire an over-exposure image; comparing each pixel of the over-exposure image with at least one threshold value; labeling a pixel of the over-exposure image as the noise while bright intensity of the foresaid pixel is lower than the threshold value; calculating a simulating value according to bright intensity of pixels around the noise and except the noise; and utilizing the simulating value and bright intensity of other pixels except the noise to execute a displacement detecting calculation.