1. A method of detecting a dead pixel in an image sensor having a pixel array to generate a plurality of image frames, the method comprising: sensing a change of a scene between first and second image frame sets, each image frame set including at least one of the plurality of image frames; and if a change of the scene between the first and second image frame sets is detected, detecting whether a dead pixel exists in the pixel array, wherein the change of scene is detected when one scene corresponding to the first image frame set is different from another scene corresponding to the second image frame set; the sensing of the change of the scene includes: calculating differences between values of at least some pixels of a window matrix of a previous image frame and corresponding pixels of a window matrix of a subsequent image frame; and determining that the scene has changed by comparing the calculated differences to a predetermined threshold value; and a number of the at least some pixels of each of the window matrices is based on an orientation of each of the window matrices within the previous image frame and the subsequent image frame, respectively.