Abstract
The use of digital image processing technologies is increasing rapidly year by year and leads to be easier for non-professionals to counterfeit security printings. Recently, reproduction protective lines are widely used in various securities as one of the anti-counterfeiting measures against the digital image processing technologies. From the view of combining anti-counterfeiting feature with aesthetic aspect and improving the latent image effect, we have proposed the divided lines method with latent image effect. However, more aesthetic and complicated design possibly leads to decrease its latent image effect. This paper demonstrates a method of providing suitable design for latent image effect to designers using the frequency analysis. Furthermore, the security printing lines comprising from the divided lines possess invisible high degree of order. Therefore, it can be deduced that those method involving the extraction of invisible high frequency component provide a medium in embedding information to printing lines without damaging aesthetic feature in geometrical printing lines.
