The Application And Research Of Watermarking To Anti-counterfeiting Packaging

Digital Watermarking featuring security, robustness and high fidelity is a new approach to maintain the technique of anti-counterfeiting and information security.The application of Digital Watermarking to the anti-counterfeiting packaging and authentication can remove the flaws in the traditional packaging. It has the advantages of exclusiveness, low cost of investment, speedy upgrade and easy differentiation and check. When the trademark or logo is digitally watermarked, it can be authenticated at the point of the supply chain, where the checking of the authenticity of the product is done and its replacement is prevented, canceling the drawbacks in security.In recent years, Watermarking embedding and collecting are processed on the basis of the plane imaging while the watermark check is directly done on the product.The package image usually changes with that of the external shape of the product. Compared with the initial picture, such a change is no longer a geometrical one like revolution, movement, contraction or amplification, but an irregular one in dimension and shape, which may destroy the synchronism between the picture and the watermark, affecting the check of the watermark.The thesis begins with the distortion issue in watermark checking, investigates the robustness of the past digital watermark algorithm, and provides solutions to the problem of the distortion.The work includes the following:1. Based on the theory of the product package design, categories of the distortion that results from the change of the external shape of the products are established and their corresponding models are made. Among the various models, the model of a wine bottle is chosen as the object of study. Based on the expreiments taken with watermark's algorithems, the needs are given on contenting the scheme of watermark to anti-counterfeiting packaging.2. A mixed blind algorithm of watermarking based on small volume robustness is offered, which combines discrete wavelet transformation and discrete cosine transformation to solve the problem of the collection of watermark when the distortion occurs with the change of the external shape of the picture. The experimental findings indicate that the algorithm has the features of watermark imperceptibility, good collection and robustness.3. A new digital watermark algorithm based on the stable features of non-equal quantization is proposed, which can be used in solving the problem of collecting and embedding of the watermark when there is a distortion with the change in the picture. The experimental findings indicate that it is a big-volume watermark algorithm, which has a better imperceptibility in the watermark, larger volume in embedding, and is still valid when the product undergoes a big swerve in angle or shift in position.