藝術網點導入高容量圖像化 QR Code 之多重防偽功能設計

Abstract

QR Code (Quick Response Code) 是串聯起虛擬與現實世界連結的重要媒介，至今被廣泛應用於日常生活當中。然而現有的QR Code，不僅視覺美感欠佳，資訊儲存容量亦有限；此外，科技日益革新、仿製手法日新月異，使真偽的辨別與預防日益艱難，尤其QR Code外觀極簡、製作便利，竄改變造等問題，仍為當今使用之一大缺陷。為此，本研究旨在不影響可讀性的前提之下，設計出一個具有高容量、高視覺品質且具備多重防偽功能的圖像化QR Code。本研究採實驗研究法，首先建立一個由一公開資訊與另八個帶有私密訊息QR Code所共同摻和而成的QR Code，透過半色調過網技術（Digital halftoning），將兩相異的藝術網點分別導入至目標圖像微結構之中，並在偽隨機（Pseudo-random number）方式下將私密資料進行加密並與之相結合。隨後，藉網屏解碼影像技術結合疊紋（Moiré pattern）原理，將其與週期性針孔狀遮罩解碼片交疊透光，即可呈現所隱藏的拼合訊息，進而驗證。同時，授權者經輸入正確密鑰數值後，亦可將QR Code中所內藏之私密訊息還原顯示，以確保資訊安全之使用目的。研究結果顯示，將多個相異QR Code偽隨機摻入，最終均能被順利還原與讀取；而藝術網點的導入，亦增進了圖像美觀性和防偽性能。此外，透過Print-and-Scan評估實體輸出後之使用性能，最終證實「階調調整」有益於降低模組與碼字錯誤率，並得出了最佳階調比例值。本研究實提供了一個嶄新的QR Code應用方法，不僅兼具美觀、高容量之特性外，其製作流程快速便利、成本低廉，亦顧及了多重防偽和資訊安全之需求，達到將公開資訊外顯、私密訊息內藏，且最終均能被成功解碼的目標。

The QR Code (Quick Response Code) serves as a crucial medium connecting the virtual and real worlds and is widely used in everyday life. However, existing QR Codes are visually unappealing and have limited information storage capacity. Additionally, with the rapid development of technology and evolving counterfeiting techniques, distinguishing authenticity and preventing counterfeiting has become increasingly challenging. The minimalist appearance and ease of QR Code production further exacerbate tampering issues. This study aims to design a Graphic QR Code that features high capacity, visual quality, and multiple anti-counterfeiting features without compromising readability. It employs an experimental research method, first establishing a QR Code composed of one public information QR Code and eight QR Codes containing private messages. Through digital halftoning technology, two different artistic screen dot patterns are introduced into the microstructure of the target image, and the private data is encrypted and combined using a pseudo-random number approach. Subsequently, by utilizing screen decoding imaging technology in conjunction with the Moiré pattern principle, the encoded messages can be revealed by overlapping with a periodic pinhole mask. Additionally, authorized users can display the hidden private messages in the QR Code after entering the correct key value, thereby ensuring information security. The research results indicate that multiple differing QR Codes, when pseudo-randomly mixed, can ultimately be successfully restored and read. The introduction of artistic screen dot patterns also enhances the aesthetic quality and anti-counterfeiting performance of the image. Furthermore, through Print-and-Scan evaluations of the physical output, it is confirmed that"tonal adjustment" is beneficial in reducing module and codeword error rates, leading to the determination of the optimal tonal ratio. This study provides a novel application method for QR Codes that not only features aesthetics and high capacity but also has a production process that is quick, convenient, and cost-effective. Additionally, it addresses the needs for multiple anti-counterfeiting measures and information security, achieving the goal of displaying public information externally while concealing private messages, all of which can ultimately be successfully decoded.