高品質低失真的資訊隱藏技術

A Data Hiding Scheme with High-Visual-Quality and Low-Distortion

本研究在探討如何利用區塊像素值差異藏入機密資料，藉由將影像分割為不重疊的三個像素，每個區塊選一個共用像素，對區塊每二個像素值加總作模數運算（modulus function），調整像素值使得模數運算的結果與藏入的資料相同，即可達到藏入資料的目地。共用像素邏輯上增加影像中的像素個數，等於增加隱藏量，另外像素的微小改變，可以增加藏密影像的視覺品質。為驗證本研究之可行性，我們在個人電腦上實作本研究所提方法，與先前的相關研究比較，實驗結果顯示本研究所提出的方法可以藏入較多的資料，且能降低對影像的破壞。

This study proposes a scheme for hiding data into an image by pixel-value differencing. We divide an image into non-overlapping blocks with three pixels. A pair of pixels in a block shares a common pixel with the other pair pixels in the block. Then apply modulus function to the sum of two pixels in the block and adjust pixel values such that the remainder is equal to the value of data to be hidden. Sharing a pixel in a block may logically increase the number of pixels in an image. This is equivalent to increasing the embedding capacity of an image. In this study, pixel value is slightly changed. Therefore, a good visual quality of a stego-image may be expected. To show the feasibility of the proposed scheme, we implemented the proposed scheme on a personal computer. Experimental results show that, comparing to previous related studies, the proposed scheme may obtain a higher embedding capacity and lower image distortion.