Image Steganography using Dynamic Threshold based on Discrete Cosine Transform

Abstract

The art of preventing the detection of hidden information messages is the way that steganography work. Several algorithms have been proposed for steganographic techniques. A major portion of these algorithms is specified for image steganography because the image has a high level of redundancy. This paper proposed an image steganography technique using a dynamic threshold produced by the discrete cosine coefficient. After dividing the green and blue channel of the cover image into 1*3-pixel blocks, check if any bits of green channel block less or equal to threshold then start to store the secret bits in blue channel block, and to increase the security not all bits in the chosen block used to store the secret bits. Firstly, store in the center of the block and then store another bit in the write or left bit depended on differences between them. The proposed method was applied to many color images and many measurement terms used to show the efficiency of it. The experiment result showed good result that the PSNR = 53.76, MSE = 0.273, SSIM= 0.999, with embedding rates 0.55

Hiding text using the least significant bit technique to improve cover image in the steganography system

“…If exact encoding is not employed frequently, this makes it difficult for a third party to decode the secret text. Taha et al [37] have used the modulus function and difference expansion (DE) to hide data in the spatial domain with increased capacity through leveraging smooth area in a cover image. Priya et al [38] recently used DE method and interpolation based data hiding with non-sequential embedding into image pixels.…”