Biometric data security using Fractional Fourier Transform and chaotic theory

Digital Watermarking using Lifting Wavelet Transform of Crowd Sourced Images

“…Lifting Wavelet Transform (LWT) transforms the image in frequency domain. Lifting wavelet is the fast wavelet transform [9] [2]. This technique makes use of split and merges rather up and down sampling in each level.…”

“…The Pseudo-random permutations technique is most suitable to change the order in which watermarking of blocks can be done. This process results in changing locations of block in which watermark bits have been embedded in the selected subband[4] [2]. No information is required about the original selected image and the original watermark prior for extracting the watermark bits other than the size of the digital watermark[10] [5].…”

“…This can act as Digital Signature, so that ownership and authenticity of images can be established for organizations. The digital watermark can resists certain level [3] [2] of distortions, malevolent attacks and contains bits of data and can co-exist with other kinds of digital watermarks. In case of nonblind watermarking schemes original image along with secret keys can be used to identify the watermark.…”

“…Protecting illegal usage of digital images has become a challenge for e-governance applications. Digital watermarking is being considered as one of the most important technique to solve problem of illegal usage of digital images [2] [8]. The characteristics of digital image watermarking must possess security, robustness, transparency along with payload.…”