Coverless Image Steganography using Haar Integer Wavelet Transform
Vivek Govindasamy, Anugrah Sharma, V Thanikaiselvan · 2020
Coverless image steganography is a recently discovered steganography method Which does not modify the image carrying the secret information. However, the techniques proposed until now have low efficiency capable of transferring few bits per image. This paper focuses on increasing the amount of data transmitted in an image, when using coverless image steganography through the use of the Haar lnteger Wavelet Transform. In our method, we take a single image of resolution 256×256 and split it into 1024 sub matrices. After that, we use integer wavelet transform to generate the coefficients in each sub-matrix. These sub-matrices are reshaped into arrays. Then the coefficients of each sub-matrix are changed into binary bits, by checking whether the succeeding value in the array is larger or smaller than the current value which leads to an array of length 1064*63. finally, we fragment the secret message into 8 bits and match it with the block and starting location in the array. A location map is generated which can be used by the receiver to obtain the secret message.