利用3D KINECT影像做資訊隱藏並應用於影像驗證、秘密傳輸及版權保護

Abstract

隨著網路及KINECT裝置的普及，在各個領域中與KINECT相關的應用也隨著增加，而在人們日常生活中藉由KINECT裝置所擷取到的影像也更為常見。然而保護這些經由KINECT裝置所獲取的3D影像資料將成為一個重要的議題。在這篇論文中，針對KINECT影像(包含深度和彩色影像)，我們提出三個資訊隱藏的方法來達到影像驗證、版權保護及祕密傳輸的目的。 在影像驗證的方面，提出了一個資訊隱藏的方法藉由嵌入驗證訊號到用KINECT裝置獲取的深度和彩色影像中來達到驗證KINECT影像的目的。所提出的方法利用KINECT影像的特性和其像素值範圍來達到同時驗證彩色及深度影像的目的。在祕密傳輸方面，針對經由KINECT影像進行秘密傳輸的目的提出了一個資訊隱藏的方法；所提出的方法利用KINECT裝置擷取的深度影像中的”depth holes”並使用新內插技術將秘密訊息藏入深度影像中並保持影像品質不變。在KINECT影像的版權保護方面，提出一個3D可視浮水印方法嵌入一個3D可視浮水印到一個結合由KINECT裝置所擷取的深度和彩色影像而成的3D影像中，此外，嵌入3D可視浮水印時會覆蓋掉原始3D影像中的某些區域，將這些區域的原始資料轉換成回復資訊並使用difference expansion方法和reversible contrast mapping方法把其嵌入到具有浮水印的3D影像中；為了防止有心人士取得回復資訊，回復資訊順序跟所嵌入的位置都經由一把秘密鑰匙打亂順序。最後，上述方法的實驗結果良好，顯示出本研究所提方法確實可行。

With the growing popularity of the Internet and KINECT devices, related applications of KINECT devices are increasing in various fields and the images acquired by KINECT devices are more commonly seen in people’s daily life. Protection of the 3D image data which are acquired by KINECT devices becomes an important issue. In this study, we propose three data hiding methods for authentication and copyright protection of KINECT images (including the depth and color images), as well as for covert communication via them. For authentication, a data hiding method for authenticating KINECT images by embedding authentication signals into the depth and color images acquired with the KINECT device is proposed. The proposed method utilizes the features of KINECT images and the ranges of the pixel values in them to achieve the goal of authenticating the color and depth images as a whole. For cover communication, a data hiding method for this purpose via KINECT images is proposed, which utilizes depth holes in the depth image acquired by the KINECT device as well as a new interpolation technique to hide secret messages in the depth image. For protection of the copyright of KINECT images, a method of 3D visible watermarking is proposed for embedding 3D visible watermarks into 3D images, which results from combining depth and color images acquired by the KINECT device. In addition, embedding the 3D visible watermark will cover some regions of the original 3D image. This problem is solved by transforming the original data of the regions into a recovery data sequence, which is then embedded into the watermarked 3D image by two schemes, one being a difference expansion scheme and the other a reversible contrast mapping scheme. In order to prevent malicious users from extracting the recovery information, the recovery data sequence and the embedding locations are both randomized by a secret key. Good experimental results are also presented to show the feasibility of the proposed methods for the related applications.