Three-dimensional optical watermarking scheme using compressed sensing in integral imaging system

Abstract

The elemental image array (EIA) is a special form of the integral imaging three-dimensional (3D) display system for recording, transmitting and displaying 3D image information, which consists of a series of small image units taken from different perspectives. There is an urgent need for protecting the copyright of EIA to improve security and anti-aggressive capability. In this paper, we propose a 3D optical watermarking scheme for integral imaging system based on compressed sensing (CS) theory. The proposed watermarking scheme consists of two subsystems, one is the EIA watermark compression and embedding subsystem, and the other is the EIA watermark extraction and display subsystem. CS theory using by phase coding mask is applied for realizing the EIA encryption and compression simultaneously, which can reduce the total amount of embedded watermark information, expand the space of secret keys and make the system more flexible and compact. The experimental results are presented to demonstrate the feasibility and effectiveness of the proposed method. The parameters of the integral imaging watermark encryption system, including the focal length and aperture of the lenslet array, the object distance, the wavelength, the diffraction distance, and the measurement matrix of CS, can all be used as the secret keys. The method proposed in this paper can effectively broaden the keys space and enhance the security of the integral image 3D display system.