Privacy Protection of Document Images Based on Quadcode

• Main Authors: Pao-Kai Chen, 陳保凱
• Other Authors: Chu-Hsing Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/19926968206512248255

碩士 === 東海大學 === 資訊工程與科學系碩士在職專班 === 97 === Abstract Following popularization of computer technology and network communication, computer users can easily transmit information all over the world by interconnection of personal computers and network equipments. Transmission of information becomes more rapid and convenient; therefore, in the open network environment, protections of the security of digital image data and rights of legitimate owners have become urgent issues. The Information Hiding technology is one kind of common methods for protections of information. By means of information hiding technology, important information is embedded secretly in multimedia of many forms, including digital documents, digital messages, digital images, digital videos, etc. Digital watermarking technologies are often used for protection of the intellectual property rights of electronic documents. The legitimate owner embeds special watermarking images to the original document to acclaim his ownership. By extracting embedded watermarks, the authenticity and the integrity of contents of the document can be verified. We propose a method to safeguard the privacy of documents: before transmitting of the content of the document via the network, we use a Quadcode coding technique to embed characters into an image to have visible watermarking effects ; in this way, the privacy and the integrity of the information are secured. If hackers intercept stego-images from the network, they are unable to deduce correctly the embedded information, only the legitimate receivers are capable to recover the hidden message. Although watermarked image is displayed as a matrix of characters, since the true document contents are mixed together with other words and phrases on the image background, it will be extremely difficult for hackers to figure out the original contents from the stego-image.