QR碼擁有容易解碼，且解碼速度快的特性，使得在人類生活中應用相當廣泛，藉由將QR碼印於海報、票劵、包裝、看板等，人們只需要使用手機APP掃描QR碼，即可很方便的獲得資訊。然而一般QR碼的外觀，是由黑色與白色方塊組成，當放在彩色背景中，容易有突兀感，在美觀方面還有可以改進的空間。又因現代仿冒、偽造商品猖獗，若能將QR碼應用於防偽與身份辨認，便能有效的解決問題。
本論文提出高度視覺性之加密雙層QR碼(Two-Layer QR Codes with High Visual Comprehensibility and Security)，第一層高度視覺性之QR碼，藉由對QR碼編碼方式做改變，使得QR碼能夠內嵌彩色圖片，達到美化的效果，並且保留QR碼解碼方便的特性；第二層加密QR碼則利用將QR碼最小單位(模組)做切割，對其做變化來放入第二層訊息，在解碼第二層訊息時，需在特定的密碼填寫區填入正確的密碼，才能夠解碼成功，若填入密碼錯誤則解碼失敗，依此便可達到防偽與身份辨認之功能。
高度視覺性之加密雙層QR碼，相較於一般的QR碼，在外觀方面，能夠將商品標誌或相關圖片直接內嵌於QR碼中，讓QR碼本身就能顯現出商品相關資訊，不需浪費額外的空間，在功能方面，增加了防偽與身份辨認，使得應用更多元化。本文以實名制票劵與寵物項圈為應用場景，模擬高度視覺性之加密雙層QR碼之編碼、解碼情況，實驗結果與事先預想的效果符合。

QR codes has the characteristics of easy and fast decoding, making it widely used in our daily. By printing the QR codes on posters, tickets, packaging, billboards, etc., people only need to use the mobile’s APP to scan the QR codes, which is very convenient to get information. However, traditional QR codes are generally composed of black and white squares, making sharp contrasts in colorful backgrounds. Therefore, from aesthetic perspective, there is still room for improvement. Realizing that counterfeiting goods are rampant in many situations, we wonder that whether QR codes can be applied to fight counterfeiting and confirm identification effectively.

In this paper, we proposed two-layer QR codes with high visual comprehensibility and security. The first layer is high visual comprehensible QR codes, achieved by changing the QR codes encoding method. The QR codes can embed color pictures to achieve beautification effect, and in the mean fine retain the convenience of QR codes decoding. The second layer is secure QR codes, achieved by dividing and modifying the minimum unit (module) of QR codes, so that we can have second-layer information. When decoding the secure QR codes, it is necessary to fill in the correct password in the specific password filling area. If the password is incorrect, the decoding fails. In this way the anti-counterfeiting and identity recognition functions can be achieved.

Compared with the general QR codes, in terms of appearance, Two-Layer QR Codes with High Visual Comprehensibility and Security can directly embed the product logo or related picture in the QR codes, so that the QR codes itself can display the product related information without waste extra space. Moreover in terms of security function, anti-counterfeiting and identification are added, making the application more diversified. In this work, the real-name ticketing and pet collars are used as application scenarios to simulate the encoding and decoding of Two-Layer QR Codes with High Visual Comprehensibility and Security. The experimental results are consistent with the expected effects.

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