Sushil Kumar and S. K. Muttoo
Image Steganography Based on Wavelet Families
Wavelet transforms are considered to be an ideal domain for image compression and transmission. The new generation still image compression standard JPEG2000 uses the bi-orthogonal CDF 5/3 wavelet (also called the CDF (2, 2) wavelet) for lossless compression and a CDF 9/7 wavelet for lossy compression. There are several known wavelet families such as Daubechies, Coiflet, Symlet, CDF, etc. The problem of selecting a suitable wavelet for signal and image processing has always challenged the researchers. The conventional wavelet filters often have floating point coefficients and couldn’t realize the lossless reconstruction.
The second generation wavelet transforms are based on lifting scheme and they map integers to integers. Thus they realize the lossless compression of image data with minimal memory usage and low computational complexity.