公开(公告)号：US11983789B1

公开(公告)日：2024-05-14

申请号：US18412497

申请日：2024-01-13

Applicant: Nanjing Normal University

Inventor： Na Ren ,  Changqing Zhu ,  Yuchen Hu ,  Qianwen Zhou ,  Heyan Wang

IPC: G06T1/00 ,  G06F21/16 ,  G06F21/60

CPC classification number: G06T1/0064 ,  G06F21/16 ,  G06F21/602

Abstract: A generation method of zero watermarking for trajectory data, a detection method of zero watermarking for trajectory data, a generation device of zero watermarking for trajectory data, a detection device of zero watermarking for trajectory data, and a storage medium are provided. The generation method divides a trajectory based on a coordinate system constructed by trajectory feature points of trajectory data into blocks, and then the moment invariants of trajectory in each block are used to construct a watermark sequence, which can achieve copyright protection without modifying the trajectory data. In addition, since the generation method uses moment invariants which can represent overall features of the trajectory to construct the watermark sequence, the generation method has strong stability in the face of common attacks and can resist almost all common types of attacks.

公开(公告)号：US12014440B1

公开(公告)日：2024-06-18

申请号：US18424760

申请日：2024-01-27

Applicant: Nanjing Normal University

Inventor： Na Ren ,  Xuchao Lv ,  Changqing Zhu ,  Qianwen Zhou ,  Heyan Wang

IPC: G06T1/00 ,  G01C21/00

CPC classification number: G06T1/005 ,  G01C21/38 ,  G06T2201/0062 ,  G06T2201/0063 ,  G06T2201/0065 ,  G06T2201/0202

Abstract: A watermarking method for a high-definition map based on invisible characters includes: firstly, establishing mapping relations between invisible characters and bit characters, a space character, and decimal digits; and combining watermark characters with corresponding positions thereof, adding Hamming code into a watermark character sequence, and converting the watermark character sequence into invisible characters to construct a composite watermark character sequence. Before watermark detection, a sequence of elements in map data is scrambled according to logistic chaotic mapping, and then the composite watermark character sequence is embedded according to the scrambled sequence. During watermark detection, the data are preprocessed, a sequence during watermark embedding is obtained, and then watermark information is extracted, errors are corrected, and an error correcting code is removed after correction to obtain final watermark information. According to the watermarking method, watermark embedding and watermark detection can be realized not changing data availability and high-accuracy characteristic.