A Novel Gaussian Error Diffusion based Colour Extended Visual Cryptography

Visual Cryptography is a technique used to protect image based secrets. This paper presents a colour extended visual cryptographic system based on Gaussian error diffusion, which results in good quality of shares and improved security. Gaussian error diffusion is applied by choosing an enumeration of pixels and the quantization error is computed. Other computations are made on the basis of threshold. Finally, XOR operation is applied for extracting the secret image. The performance of our proposed system is measured in terms of Peak Signal to Noise Ratio (PSNR), Normalized Correlation Coefficient (NCC) and Mean Square Error (MSE) and is shown in experimental results. Keywords— Visual Cryptography, Gaussian error diffusion.