Patent ID: 9692984
Date: 2017-06-27
CPC Classifications: G06F,G06K,H04M,H04N,H04W

Claim:
1. A method of operating a camera-equipped mobile phone, the method comprising the acts: activating a first LED light source of a first visible light color, for a first interval, while capturing image data from a subject using said mobile phone, the subject having previously been printed with an image conveying a steganographic digital watermark that modulates at least one color channel, but does not modulate all color channels of the image as modulation of image luminance: activating a second LED light source of a second visible light color different than the first, for a second interval different than the first, while capturing image data from said subject using said mobile phone; and processing the captured image data to extract payload data from said steganographic digital watermark.