Watermark design of two-dimensional barcodes on mobile phone display by evolutionary multi-objective optimization

Two-dimensional (2D) codes have been increasingly spread for the quick verification items such as airplane boarding passes, train tickets, and coupons. However, the illegal duplication or fabrication of 2D codes has yet to be investigated. This study proposes a semi-fragile watermark design method for detecting illegally copied 2D codes on mobile phone display. The proposed method evaluates solutions with real mobile phones rather than simulation. In addition, we formulate the watermark design problem as a multi-objective optimization problem involving an objective function for every mobile phone, resulting in producing a valid watermark on various mobile phones. Experimental results show that the proposed method can obtain a better semi-fragile watermarking scheme than that by single-objective optimization method.