Three Dimensional Point Clouds Watermarking Algorithm Based on Sphere Degenerated Octree

Abstract

To ensure the security and integrity of three dimensional point clouds model during transmission in the network, according to their own characteristics, after the pretreatment of PCA (Primary Component Analysis), three dimensional point clouds watermarking embedding algorithm based on sphere degenerated octree was proposed, and the octree that contained the original point clouds model was subdivided multilevel from top to bottom, and the nodes of the octree were ordered. And three dimensional point clouds watermarking extraction algorithm was proposed, and the original point clouds model and the watermarked model were registered accurately, and the occurrence of synchronization error was avoided. Experimental results showed that the presented algorithm was robust to many attacks such as rotation, translation, uniform scaling, vertices reordering, simplifying, noise and cropping under blind detection.

Security Protection of 3D Models of Oblique Photography by Digital Watermarking and Data Encryption

“…A mapping relationship is established between the watermark data = w (i,j) , 0 ≤ i ≤ h − 1, 0 ≤ j ≤ h − 1 and the distance D between the feature point and the virtual centroid. For the m-th texture coordinate T m (U m , V m ), the corresponding row and column numbers r, l in the watermark w are calculated according to Equation (6).…”

“…In Equation (6), trunc(a, b) represents the truncation of a to b digits after the decimal point, Int( * ) represents the integer part of a decimal number, Hash( * ) represents a function that converts an input of arbitrary length into a fixed length output, divmod(a, b ) represents the quotient and remainder, where a is the divisor and b is the dividend, d m represents the number of digits to retain after the decimal point for the distance D Tm from the texture coordinate to the origin of the texture coordinate, and mod represents the remainder calculation.…”

“…Against this background, it is particularly important to take effective protective measures to prevent data theft and illegal dissemination. Digital watermarking [6] and data encryption [7], two representative technologies of data security protection, have been considered as effective means for security protection of 3DMOP [8].…”