The aim of image restoration is to estimate the original image from an observation image degraded by blur and additive noise as much as possible. Different image restoration methods have developed by many researchers. The methods reviewed in this paper are Non Linear Total Variation, PDE noise removal algorithm, Hybrid image restoration and Wavelet Analysis method. These methods having some dra...

Abstract. Image compression methods such as JPEG use quantisation of discrete cosine transform (DCT) coefficients of image blocks to produce lossy compression. During decoding, an inverse DCT of the quantised values is used to obtain the lossy image. These methods suffer from blocky effects from the region boundaries, and can produce poor representations of regions containing sharp edges. Such ...

centrated around the edges. At a compression of 166:l (0.048biV pixel), the JPEG reconstruction (Fig. If, 26.33dB) gives a very blocky image. It is worth noting that the colours in the JPEG reconstruction (Fig. In are totally different from those in the original. This Letter has presented a very simple and effective adaptive image coding scheme which requires no training, no storage of codebook...

Abstract. We present a variational framework for shape optimization and shape reconstruction problems in seismic domains based full waveform inversion. We discuss general shape functionals in this framework, along with applications to shape optimization using the Helmholtz equation and image domain segmentation. We study the shape derivative in each case to express the variation of energy with ...

The ability to read expressions on human faces is hardwired in the human brain, as a very powerful tool to sample non-verbal information about the emotional disposition of other people. Nowadays, more and more face-toface interactions are happening over multimedia systems, including video conferencing, watching movies and interacting with virtual characters. Some of these systems usually rely o...

SENSE reconstruction suffers from an ill-conditioning problem, which increasingly lowers the signal-to-noise ratio (SNR) as the reduction factor increases. Ill-conditioning also degrades the convergence behavior of iterative conjugate gradient reconstructions for arbitrary trajectories. Regularization techniques are often used to alleviate the ill-conditioning problem. Based on maximum a poster...

It is common to find spatially repetitive patterns in animal visual signals. The evolution of such patterns is not well explained by existing theories of signal evolution. In this paper, we suggest that the evolution of signals with spatial repetition may be due to specific recognition problems and receiver biases. The logics of our hypotheses are studied in co-evolutionary simulations using ar...

The surface thermal properties of Phobos and Deimos have been determined from observations made with the Viking Orbiter Infrared Thermal Mapper (IRTM), at wavelengths ranging from 6 to 20 •m. The data, composed of both global and high-resolution infrared photometry of the satellite surfaces as well as eclipse observations, indicate surface material of low thermal conductivity comparable to that...

A secure method for steganography is proposed. Pixelvalue differencing (PVD) steganography and bit-plane complexity segmentation (BPCS) steganography have the weakness of generating blocky effects and noise in smooth areas and being detectable with steganalysis. To overcome these weaknesses, a secure bit-plane based steganography method on the spatial domain is presented, which uses a robust me...