A novel data hiding method for covert communication via the QR code image based on adjustments of the shapes of the QR code modules using image processing techniques is proposed. A module block consisting of two module pairs is taken as the unit for message-bit embedding by adjusting the vertical and horizontal internal boundaries in the module pairs. Eliminations of the resulting boundary line zigzaggedness and irregular overlapping and holing phenomena in the module block are also carried out. The resulting stego-image with secret bits embedded can be scanned by a barcode reader to obtain the facial data recorded in the QR code while a program implementing the message extraction process of the proposed method can process the stego-image to extract the hidden secret message. Good experimental results, tests of stego-image readability by QR code scanners and resistance to noise attacks, and a comparison with other methods from the viewpoint of data embedding rate show the feasibility and superiority of the proposed method for real covert communication applications.

中文翻译：

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通过基于模块形状调整的数据隐藏技术通过QR码图像进行秘密通信

提出了一种新的数据隐藏方法，该方法通过使用图像处理技术对QR码模块的形状进行调整来通过QR码图像进行秘密通信。通过调整模块对中的垂直和水平内部边界，将包含两个模块对的模块块作为消息位嵌入的单元。还消除了模块块中产生的边界线之字形和不规则的重叠和空洞现象。条形码阅读器可以扫描生成的带有秘密位的隐藏图像，以获取记录在QR码中的面部数据，而实现所提出方法的消息提取过程的程序可以处理该隐藏图像，以提取隐藏的秘密消息。实验效果不错，