Research On Digital Watermarking For 2D Electronic Chart

Two-dimensional electronic chart with the characteristics of high fidelity and high precision has great value in the fields such as ship transport,naval equipment and marine development.Watermarking technology is an effective method to protect the security of the digital media which can identify the own characteristic information of theelectronic chart,so it is particularly suitable for the content protection of two-dimensional electronic chart.The researchof content protection of two-dimensional electronic chart is rare at home and abroad,and the watermarking strategies are deficient in robustness,tampering,and dissemination.In addition,compared with other digital medium,the two-dimensional electronic chart has low data coupling and rich primitive type,which makes the watermark embedding operation more difficult.This paper uses the safe model of two-dimensional electronic chart watermarking as the study subject,in order to ensure the security of electronic chart content as the research content,and achieve the safe application of two-dimensional electronic chart,reduce the security risk as the goal,two-dimensional electronic chartless watermarking method,The two-dimensional electronic chart authority watermarking method to start,through the two-dimensional electronic chart security watermark key technology,algorithm research,not only lay the theoretical foundation for the electronic chart watermarking technology,but also provides an effective solution for the ocean power strategy under the sea map data security and certification.In this thesis,the concrete research content is as follows:Combined with the structural features and data structure of electronic chart,this paper presents a double features based two-dimensional electronic chart watermarking algorithm.Digital map watermark is essentially an information hiding problem,and conventional information hiding technology will cause content disturbance or data damage.This paper analyzes the intrinsic relationship between the contents and data of two-dimensional electronic chart with its data structure and file structure in detail.On this basis,the paper carefully designs the e-chart data content perturbation model of the watermark,and analyzes the effect to the accuracy of the original data caused by watermark embedding intensity,and controls the error and selects the appropriate watermark capacity and embedded parameter.The proposes algorithm that is based on singular value decomposition gets the initial set of reference positions for watermark embedding,and obtains the maximum watermark embedding capacity by reasonable gray balance method,and controls the perturbation of the e-chart in order to achieve the adaptive embedding and extracting operation of the digital watermark.The paper proposes the Difference Map based digital watermarking Algorithm for two-dimensional e-chart based on Wavelet Translation scale invariance.The e-chart has the accuracy diversity which is different from the conventional vector map.The accuracy diversity is that the e-chart uses the geographic coordinate systems of the ocean and the land at the same time.The accuracy of the two geographic coordinate systems can respectively achieve 10^-710^-9 and 10^-1310^-15.Thus,there are many inconsistencies in the frequency domain and airspace algorithms by adjusting the coordinate values to embed the digital watermark.Firstly,this paper converts the electronic chart into a general map by Translation invariant Policy.Secondly,it embeds the watermark into the map continuously through the gradient-based feature point selection strategy.Thirdly,it achieves the balance of usability and safety by using the difference algorithm,and adapts to the characteristic of"complicated meta-type and low data coupling".Combined with the security watermark model,put forward a two-dimensional electronic watermarking algorithm based on semantic information.Permission watermark,also known as"safe watermark",is a kind of reversible watermark.But the permissions watermark logo contains the operating characteristics of the chart and file attributes,by analyzing the watermark logo can limit the user operating authority.Firstly,construct the watermarking identifier,and the embedding method is embedded in the two-dimensional electronic chart by the adaptive embedding method and the lossless watermarking method.After the operation of the chart,the operating system kernel can be controlled by driving the filtering and message interception The technology implements the interception and release operations for chart operation rights.The concept of semantic feature coding is introduced,and the digital map authority information is encoded and transformed into the feature classification library of semantic image,so that the feature of watermark image has the definition of permission code.Because of the detection and extraction of watermark information,it is transformed into feature matching and semantic analysis of semantic images,which makes the detection of watermark information improved and can better restore the semantic information of watermark.The double features based two-dimensional electronic chart watermarking algorithm and wavelet translation scale invariance policy can control and reduce the content perturbation of the watermarking algorithm.By combining the semantic feature,these watermarking methods can resist a variety of forms of attacks and have strong robustness.These watermarking methods achieve the safe application of two-dimensional electronic chart.