1. A method for detecting overlay graphic presence within a frame of image data comprising: specifying a first location corresponding to a pixel location within the frame of image data; estimating a background pixel value for the first location, thereby providing an estimated background pixel value, wherein the estimated background pixel value is responsive to one or more image pixel values corresponding respectively to one or more pixel locations that are spatially separate from the first location, and within the frame of image data; estimating a blended pixel value for the first location, thereby providing an estimated blended pixel value; receiving a first image pixel value for the first location; and evaluating a graphic presence criterion corresponding to the first location to determine presence of the graphic corresponding to the first location, responsive to: the estimated background pixel value, the estimated blended pixel value, and the first image pixel value, to provide a graphic presence indicator value corresponding to the first location.