The Mosaic And Check Of Digital Watermark

The rapid development of multimedia technology and popularization ofInternet has brought a series of problems in the areas of politics, economy,military affairs and culture and yielded many research hotspots, such assafeguarding the intellectual property of numeral works, preventing bondcounterfeit in trade, hiding marks and revising suggestion on sound-to-picturedatum, secret communication, etc. Among these issues, numeral watermarktechnology has achieved rapid progress and at the same time some typicalalgorithms have appeared.This essay brings up an algorithm of color images that can identify theposition of color images form simplex or almost simplex background. To befurther, the color images with inlayed mark codes can be examined outaccording to related examining principles after the images have been cut out,leveled move, printed and scanned and dealt with other normal ways, such aslowpass filtering,gaussian noise and JPEG compression and so on.Many new algorithms appeared with the development of numeralwatermark algorithms. Based on the materials on this field, most of thepresent algorithms are aimed at pure numeral filed, among which some canbe applied to mimic field. But they cannot solve the difficulties of cutting out,spinning, leveled moving of images. The algorithm brought up in this passagenot only can be used in the pure numeral field, but also can solve thedifficulties mentioned above.Applied fields: through examining the existence of many-watermarksto identify the truthfulness of images and to protect the legal right of users.According to the research achievements, the features of the algorithmare as follows.1. To introduce the encoding ideas of random sequence base.Through beforehand random sequence base the algorithm cantransform original information in the form of numbers, text, audio and videointo random sequence watermark with the examining characteristic of thebinary system.The present algorithms that take random integers as the watermark,because of not taking random sequence base, can merely explain whetherthere is watermark and cannot carry enough original information. On theother hand, if we use the original information directly, the quality or Robustand examining can not compared with random sequence watermark.