A Study on Output Control of Watermarking with Blended Halftone Dots

• Main Author: 吳鴻明
• Other Authors: 王希俊
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/06994697161978730088

碩士 === 國立臺灣師範大學 === 圖文傳播學系 === 95 === The objective of this thesis is to hide watermark with hybrid halftone dots in a printed halftone image. Two different halftone dots, Amplitude Modulation (AM) and Frequency Modulation (FM), are use to design the digital watermark. The output parameters should be carefully controlled to obtain printed image with hidden digital watermark. As the printed image is copied or scanned, the hidden watermark is shown because of the under-sampling of the FM halftone dots. The outcome of this research has many potential applications in security printing, such as ID, legal document, checks, stamps, and currency.