The preservation of high peak signal-to-noise ratio of the watermarked image is required in some applications. The chaos-based fragile watermarking proposed by Rawat et al. in 2011 can meet this requirement, for only one LSB plane of the original image is modified by the watermark data. However, there are three drawbacks in the original scheme: (i) insecurity, the host image can be tampered wit...

Medical image registration plays a crucial role in clinical diagnosis, treatment, quality assurance, evaluation of curative efficacy and so on. In this paper, by computing the medical image moments, the centroid is obtained, and according to the rotational invariance of the singular values of the matrix of the medical image coordinates, the rotation angles of the reference and floating images a...

The impact of using different lossy compression algorithms on the matching accuracy of iris recognition systems is investigated. In particular, we relate rate-distortion performance as measured in PSNR to the matching scores as obtained by a concrete recognition system. JPEG2000 and SPIHT are correctly predicted by PSNR to be well suited compression algorithms to be employed in iris recognition...

In the context of joint source and channel coding, unequal loss protection is often used to make image data more robust to possible packet losses. The allocation of source and code symbols is customarily done so as to maximize the expected PSNR at the receiver. In this paper we propose a new objective function, attempting to maximize PSNR given a constraint on the system probability of failure,...

The wavelet based SPIHT algorithm has recently attracted significant attentions from researchers in image coding. SPIHT maximizes PSNR (or minimize MSE) for each bit it transmitted, however, it is well known that PSNR is not a good indicator of the perceptual image fidelity. Human visual perception is more sensitive to distortions in lower frequency components than distortions in the higher fre...

Block Truncation Coding is one of the easy and efficient techniques for lossy image compression. In this paper, we have proposed few methods to enhance the existing Interpolative and Lookup procedures to reduce the bitrate and to improve the PSNR obtained with the Block Truncation Coding (BTC) based image compression methods. Of the existing BTC based methods, we have implemented the Minimum Me...

An ultrasound image provides the radiologist with noninvasive, low cost, and real-time images that can help them in diagnosis, planning and therapy. However low PSNR (picture signal to noise ratio) in ultrasound images causes difficulties in correct interpretation of ultrasound images. Further speckle noise present in ultrasound images is considered to be the major cause of its low PSNR. In thi...