Özet:

Digital image steganography techniques deal with three subjects lossy/lossless compressed images, uncompressed images. Steganography techniques embed secret data pixel directly into uncompressed and lossless compressed cover images. The most popular data hiding method is, changing pixels’ left most digits or last two, known as Least Significant Bit (LSB). Lossless image formats like .bmp, .png, and 8-bit gray-scale .gif are usable for LSB methods. LSB embedding method is not usable for palette images because of changing just last bit of a pixel causes a big difference on image. After embedding all of secret message to palette image, Human Visual System (HVS) can detect manipulations on image. In this study, we compare some of the most popular LSB techniques; Chan’s algorithm [3], 2/3 efficient embedding [4], matrix embedding for large payloads [5], image blocks method [6] and pixel-value differencing method [7]-[8].

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