Fig. 1. Diagram of dot displacement

Fig. 2. Diagrams of anti-counterfeiting labels embedded by phase modulation method. (a) Dots on hidden layer; (b) preoutput map after superposition of four color channels

Fig. 3. Local enlargement diagrams of latent image boundary dots. (a) Diagram of upper boundary dot adjustment; (b) diagram of lower boundary dot adjustment

Fig. 4. Flowchart of adjustment scheme

Fig. 5. Comparison of concealment effects. (a) Hidden areas of latent images; (b) original method; (c) improved method

Fig. 6. Comparison of extraction effects. (a) Original method; (b) improved method