1. A foreground object detection method, the method comprising: establishing a background model by establishing a blank model to receive the first frame of N frames of a video stream generated by a camera; reading a current frame of the N frames and detecting a pixel value difference and a brightness value difference for each pair of two corresponding pixels in the background model and the current frame for each of the N frames of the video stream, wherein the current frame is selected in sequence from the second frame to the N frames of the video stream; determining a foreground pixel in the current frame upon the condition that the pixel value difference and the brightness value difference of the pixel in the current frame are greater than a pixel threshold and a brightness threshold, respectively; and identifying a foreground object in the current frame in accordance with the foreground pixel.