12. On-the-Fly Microtext Generation

Microtext is an important aspect of security printing. At times, the embedding of copy protection in documents that are printed by a conventional office printer is required. In this chapter, we present a method for on-the-fly microtext generation. In general, the approach is applicable to any language and a wide set of typefaces. The technique consists of rendering a symbol to an intermediate image and creating a skeleton by iterative thinning and downsizing of the skeleton to target a micro-symbol bitmap. Optionally, the thickness of lines can be increased. Possible targets in the printing pipeline for implementation of the microtext generator are discussed and the advantages of the method presented over conventional text printing with an extremely small font size are demonstrated.