AN IMAGE CONTENTS SECURITY SYSTEM FOR DIGITAL HOLOGRAPHIC BROADCASTING SERVICE AND THE METHOD THEREOF

摘要

The present invention relates to an image content encryption system and method for a digital holographic broadcasting service, which are capable of encrypting depth information and an RGB image for a digital holographic display system, but encrypting only DC coefficients by performing quad-tree division of an image, based on edges, and performing discrete cosine transform (DCT). The image content encryption method comprises the steps of: (a) detecting edges from depth information of an original image; (b) performing quad-tree division of the depth information using the detected edges to divide the depth information into blocks; (c) performing variable block size-discrete cosine transform (VBS-DCT) according to the size of the divided block to obtain frequency components (DC); (d) encrypting the coefficients of the obtained frequency components to create the encrypted frequency components; and (e) performing inverse VBS-DCT of the encrypted frequency components to obtain an encrypted image. By the image content encryption system and method as described above, visual information of an original RGB image and depth information can be hidden by encrypting only a part of the entire image data. [Reference numerals] (41) Outline detection unit; (42) Quad-tree division unit; (43) DCT processing unit; (44) Encryption unit; (45) Reverse DCT processing unit; (46) Block synthesis unit; (AA) Original image; (BB) Encrypted image