資料隱藏技術主要是設法把重要資訊隱藏於數位化媒體(如圖像、聲音、視訊)之中。利用像素值之調整可達到藏密之目的，倘若能同時整合像素差值法與最低位元法，則更可以提升藏密資料量。本論文所提出的演算法，先使用像素差值法藏入資料，再利用最低位元取代法來調整已隱藏資料的像素值，以增加藏密容量，並同時降低對圖像品質之影響，抽取隱藏資料的方式則可以反方向進行之。實驗結果顯示，當藏密容量需求增加時，本論文所提方法與像素差值法及像素差值和最低位元取代合併法比較後，本論文所提方法之優點是可以同時增加藏密容量，並保持圖像品質的。 The purpose of information hiding is to embed important message into digital media, such as images, voice, and video. Information hiding can be achieved by adjusting the pixel values inside the image and the hiding capacity can be increased by integrating the methods of pixel-value differencing (PVD) and LSB replacement (LSBR). To increase hiding capacity and reduce image degradation, this paper presents a hiding algorithm by firstly embedding information into the image using PVD and
then adjusting the altered pixel values using LSBR to hide more information. The information extraction can be done along the reverse direction. Experimental results demonstrate that the proposed approach can increase the hiding capacity and keep the image quality simultaneously, while compared with the method of pixel-value differencing (PVD) and the combined version of PVD and LSBR.
