Patent ID: 8356319

Claim:
A method of triggering a screen saver, the method being implemented in a system having a display, the method comprising: outputting a current frame of a video on the display; selecting a sparse subset of pixels from a total number of pixels of the display; determining a plurality of pixel values for each pixel in the sparse subset, each respective pixel value of the plurality of pixel values being determined based on a respective previous frame previously output on the display; evaluating only the pixels in the sparse subset, by independently evaluating each respective pixel in the sparse subset using the plurality of pixel values for the respective pixel and a current value of the respective pixel in the current frame to determine whether the respective pixel has undergone a threshold amount of change in value over a plurality of frames; and triggering the screen saver to modify the video being output on the display in response to determining that a plurality of pixels in the sparse subset have not undergone the threshold amount of change in value over the plurality of frames.