Image quality assessment (IQA) is a crucial technique in perceptual image/video coding, because it is not only a ruler for performance evaluation of coding algorithms but also a metric for ratio-distortion optimization in coding. In this paper, inspired by the fact that distortions of both global and local information influence the perceptual image quality, we propose a novel IQA method that in...

Because of the poor radio frequency coil uniformity and gradient-driven eddy currents, there is much noise and intensity inhomogeneity (bias) in brain magnetic resonance (MR) image, and it severely affects the segmentation accuracy. Better segmentation results are difficult to achieve by traditional methods; therefore, in this paper, a modified brain MR image segmentation and bias field estimat...

In this paper, we examine the applicability limits of different methods compensation individual properties self-emitting displays with significant non-uniformity chromaticity and maximum brightness. The aim is to minimize perceived image non-uniformity. Compensation displayed based on minimizing distance between target (ideally displayed) simulated by calibrated screen. S-CIELAB model human vis...

In this paper we describe a metho.d. for estimating boundaries between percep~ually d1stmct regions in an image. The method 1S a two step procedure which first identifies image regions ~hich exhibit uniformity. Boundaries between umform regions are approximated by a complete cubic spline function and the linear recursive filter is used to estimate the values of the function at the knots. Bounda...

Any permutation with a low differential uniformity is shown to be such that its inverse has a derivative with a large image set. An attack exploiting this structural property is then presented against a recent hash function proposal, named Maraca, submitted to the SHA-3 competition. Moreover, the attack can be made much more efficient when the image sets of the derivatives of the inverse permut...

Simple Linear Iterative Clustering (SLIC) algorithm is increasingly applied to different kinds of image processing because of its excellent perceptually meaningful characteristics. In order to better meet the needs of medical image processing and provide technical reference for SLIC on the application of medical image segmentation, two indicators of boundary accuracy and superpixel uniformity a...

The perceptual gloss space defined in Pellacini et al. [9] could be used for quality control applications to bring similar benefits as seen in color with the use of CIELAB. However, a distance metric to relate all the dimensions in the space does not exist, and the space was only validated with the materials used to define the space. The current space’s distance metric does not allow relating d...

In this paper, a model of two-wave mixing in the photorefractive crystal, which takes account of the difference in spatial frequency in a beam, has been built to study the image enhancement effect in coherent optical amplification. Based on the theoretical analysis of the model, the gain distribution for each pixel in the signal beam has been obtained. It shows that the unevenness of the gain i...

We present a method of ordering pixels (the elements of a rectangular matrix) based on an arithmetic progression with wrap-around (modular arithmetic). For appropriate choices of the progression’s parameters based on a generalization of Fibonacci numbers and the golden mean, we achieve uniformly distributed collections of pixels formed by intervals of the pixel progression or “shuffle.” We illu...