資訊嵌入或資料隱藏的技術，都是能夠使我們秘密嵌入額外資料在數位檔案的方法，而這些數位檔案包括了影像檔、電影檔、以及聲音檔等。一般來講我們將資訊嵌入或資料隱藏的技術分成兩大類的應用，一則是應用在數位版權的保護方面，也就是數位浮水印；一則是應用在秘密通訊方面，也就是隱像學。這兩大類的主要分別在於它們對所藏入資訊強調的重點不同，在數位浮水印裡，我們所著重的是藏入資料(數位浮水印)的強韌性，這樣才能確保當數位檔案遭受惡意修改、攻擊時，依舊能夠從中取出我們的數位浮水印來證明這個數位檔案是屬於我們所有；而在秘密通訊裡，我們所著重的則是在不影響原始影像下可藏入資料量的多寡。在秘密通訊裡我們若將所藏入資訊改為是對影像或數位檔案的註解或註釋的話，則可用來做資料管理。本篇論文則是著重於在不影響原始影像下使可藏入資料量更多。
近年來，在資料隱藏的技術上，通常是藉由修改一些在原始影像裡面中較不重要的資訊，以達到所求並不影響原始的影像，目前最主要的研究領域可分成兩類：一則是在Spatial domain下對影像資料作處理；一則是在Frequency domain下對影像資料作處理。在Spatial domain中最常用的方法是去修改影像裡面的least significant bits(LSB)，以減少對影像品質的影響；在Frequency domain中則是在頻率域中選擇人眼較不敏感的高頻去嵌入我們所要藏入的資訊。一般圖檔分為黑白圖、灰階圖、與彩色圖，在本篇論文我只針對彩色圖檔來做探討與研究，因為彩色圖檔是一般較常被使用的圖檔，並且由於其本身的資料量大，相對可嵌入的資料量也會比較大。
本篇論文分別對常用的彩色圖檔BMP檔與JPEG檔提出可在Spatial Domain與Frequency Domain下嵌入相當資訊量並且保持一定品質的方法。在Spatial Domain中的作法，會利用像素區域的影像特性來決定所藏的資料量多寡在搭配所使用的小技巧，減少影像的失真度;而在Frequency Domain中的作法主要會依據原本標準量化表的特性去做修改，進而得到可藏入資料的空間。

In this paper, two simple information hiding techniques for color images in the spatial domain and the frequency domain are proposed. In the spatial domain, we divide the original image into 2x2 sub-blocks and check each sub-block if it has an edge point. If yes, we embed more data in this sub-block and blue channel. In the frequency domain, the proposed mechanism modifies the standard quantization table first. Then the data is hidden in the cover-image with its quantized DCT coefficients modified. We compare our method with other methods and a JPEG hiding-tool Jpeg–Jsteg. From the experimental results, we obtain that the proposed methods has a larger data hiding capacity than other methods and Jpeg–Jsteg, and the quality of the stego-images of our methods is acceptable.

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