Visual Cryptography and Secret Image Sharing

2

Visual Cryptography for Color Images

Stelvio Cimato

Università, degli Studi di Milano, Italy

Roberto De Prisco

Università di Salerno, Italy

Alfredo De Santis

Università di Salerno, Italy

CONTENTS

2.1 Introduction

2.2 Color Superposition

2.2.1 Color Vision and Color Models

2.2.2 Lattices

2.2.3 The Darkening Problem

2.2.4 The Annihilator Color

2.2.5 The Identity Color

2.3 Formal Models for Colored VCS

2.3.1 The Models for B&W-VC

2.3.2 The Models for Color-VC

2.3.3 The SC, ND, and General Models

2.3.4 Base Matrices

2.4 Schemes for the SC Model

2.4.1 The VV Schemes

2.4.2 The BDD Schemes

2.4.3 The KY and YL Schemes

2.4.4 The CDD Schemes and a Lower Bound

2.5 Schemes for the ND Model

2.6 Schemes for the General Model

2.6.1 (2, 2 Threshold ...