高保真像素排序可逆資訊隱藏法之探究

A Study of High-Fidelity Reversible Data Hiding Using Pixel Value Ordering Methods

可逆式資訊隱藏在近年來崛起一項新穎的方法稱之為像素排序法。與以往的可逆式資訊隱藏方法相比，像素排序法可在藏入機密訊息後有較高的影像品質，藉此許多學者以基於像素排序法將機密訊息藏入於預測誤差值當中，或是藉由影像的特性利用區塊的方式進行分析，並藏入機密訊息，促使像素排序法不斷的更新，以達較佳的藏入效能。本論文將針對各種像素排序法進行分析以及比較藏量及影像品質的效能，並以亦為各種像素排序方法提供範例說明，提供讀者更有效地了解像素排序方法的特性。

A novel reversible data hiding methods based on pixel value ordering, also called PVO, has been widespread concerned by the researchers in the field of data hiding, because the incorporation of PVO-based reversible data hiding has higher image quality than that of well-known reversible data hiding methods. To date, several improvements of the PVO method originated form Li et al. have been proposed. In order to increase the embedding capacity and preserve good image quality, most of authors make the proper use of the image characteristics, such as pixel correlations, block textures and region complexity, etc. In this paper, various PVO-based reversible data hiding schemes are studied. The analysis and comparisons among those methods are discussed such that the researchers who are interested in the field can catch the essence of PVO methods.