1. A method of finding stable keypoints in a picture image using localized: scale space properties, comprising: calculating an integral image of an input image; constructing a scale space pyramid layer representation of the input image at multiple scales, wherein at each scale, a set of specific filters are applied to the input image to produce an approximation of at least a portion of the input image; combining an output of the filters together to form a single function of scale and space; identifying stable keypoint locations in each scale as pixel locations at which the single function attains a local peak value; and storing the stable keypoint locations in a memory storage.