Patent ID: 8185596
Filing Date: 2012-05-22
Classification: H04W

Abstract:
1. A method for providing location-based messages, comprising the steps of: (a) searching among a plurality of world object for a suitable placeholder for a virtual message by using a handheld device provided with image acquisition apparatus; (b) selecting one of said plurality of world objects as a placeholder by filtering world objects which are not visually isolated from their surroundings and which are not planar and by applying predetermined classification tests; and (c) attaching one or more virtual messages to an image that identifies said selected placeholder; wherein the step of selecting one of said plurality of world objects as a placeholder is carried out by performing the following operations: wherein a region of the sufficiently high image gradient is identified by projecting gradient image content on two orthogonal axes and analyzing said projected gradient image content with respect to compliance with the predetermined classification tests.