Fig. 4From: A copyright protection scheme for digital images based on shuffled singular value decomposition and visual cryptographyExample of cat map encryption: a Pixel values of an image of size 8 × 8, b Encrypted pixels with \( N_{2} = 1 \), c Encrypted pixels with \( N_{2} = 2 \), d Encrypted pixels with \( N_{2} = 3 \) and e Encrypted pixels with \( N_{2} = 4 \) Back to article page