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A new approach to Image Quality Assessment (IQA) is presented. The idea is based on the fact that two images are similar if their structural relationship within their blocks is preserved. To this end, a transition matrix is defined which exploits structural transitions between corresponding blocks of two images. The matrix contains valuable information about differences of two images, which should be transformed to a quality index. Eigen-value analysis over the transition matrix leads to a new distance measure called Eigen-gap. According to simulation results, the Eigen-gap is not only highly correlated to subjective scores but also, its performance is as good as the SSIM, a trustworthy... 

With the ever-growing portion of internet traffic associated with multimedia data and the existence of multiple copies of the same content in various forms, it has become vital to measure the quality of the image and video files. In most cases, without access to the original file, the quality shall be assessed solely based on the available file. Specifically, the challenge of no-reference image quality assessment (NR-IQA) is to predict a quality measure for given images in a consistent manner with human perception of quality. Conventional NR-IQA methods try to fit certain distortion models to a given image and quantify the quality. In practice, however, an image is affected by a combination... 

With the recent advancements in deep learning, high performance neural networks have been introduced. These neural networks also can be used to solve similar problems in a transfer learning approach. Recently, several state-of-The-Art Convolutional Neural Networks (CNNs) are proposed for computer vision tasks. On the other hand, in-The-wild No-Reference (Blind) Image Quality Assessment (NR-IQA) problem is known as a challenging human perceptual problem. In this paper, a transfer learning approach is used to solve the problem of in-The-wild NR-IQA. With a few training times, the proposed neural network exceeds all the previous methods which are not using deep neural networks. Further, the... 

Radiographic inspection is the most appreciated technique among the other non-destructive testing methods due to producing unique finger print record as the film. Converting of radiographs to a digital format and further digital image processing is the best method of enhancing the image quality and assisting the interpreter on his evaluation. In this research, different algorithms were used for image enhancement and radiograph interpretation in MATLAB environment. A graphical user interface (GUI) was created for implementation of different algorithms. Both spatial and frequency (wavelet) domains techniques were used for image enhancement. Results showed that the defect recognition... 

In recent days imaging systems have seen considerable extended usage due to their ease of use and reasonable price. However, they have weaknesses lies in image resolution. In order to increase the quality of the images, due to the technical limitations and costs of hardware parts, software techniques like the super-resolution is used, which means increasing the density of pixels in the image. The super-resolution is broken down into two categories; super-resolution using a single image and super-resolution using multiple images. In this paper, a method for increasing image quality, based on the Dong method has been proposed. In the proposed method, which is based on only one image, tries to... 

Recently, deep convolutional neural networks (DCNN) that leverage the adversarial training framework for image restoration and enhancement have significantly improved the processed images' sharpness. Surprisingly, although these DCNNs produced crispier images than other methods visually, they may get a lower quality score when popular measures are employed for evaluating them. Therefore it is necessary to develop a quantitative metric to reflect their performances, which is well-aligned with the perceived quality of an image. Famous quantitative metrics such as Peak signal-to-noise ratio (PSNR), The structural similarity index measure (SSIM), and Perceptual Index (PI) are not well-correlated... 

This paper reports on the NTIRE 2021 challenge on perceptual image quality assessment (IQA), held in conjunction with the New Trends in Image Restoration and Enhancement workshop (NTIRE) workshop at CVPR 2021. As a new type of image processing technology, perceptual image processing algorithms based on Generative Adversarial Networks (GAN) have produced images with more realistic textures. These output images have completely different characteristics from traditional distortions, thus pose a new challenge for IQA methods to evaluate their visual quality. In comparison with previous IQA challenges, the training and testing datasets in this challenge include the outputs of perceptual image... 

Capacity is one of the most important parameters in image watermarking. Different works have been done on this subject with different assumptions on image and communication channel. However, there is not a global agreement to estimate watermarking capacity. In this paper, we suggest a method to find the capacity of images based on their complexities. We propose a new method to estimate image complexity based on the concept of Region Of Interest (ROI). Our experiments on 2000 images showed that the proposed measure has the best adoption with watermarking capacity in comparison with other complexity measures. In addition, we propose a new method to calculate capacity using proposed image... 

An efficient multi-static millimetre-wave (MMW) imaging system is proposed with the aim of obtaining the information of an axially tilted object. It is known that a multi-static structure performs better than a mono-static array in detecting the reflected signal from axially tilted surfaces due to the specular reflection. Still, no efficient multi-static structure for the purpose of imaging tilted objects in view of the computational time, cost and image quality is proposed till now. The authors propose an efficient multi-static MMW imaging system tackle this issue with the minimum number of antennae. Furthermore, the small number of antennae in the proposed design and the proposed fast... 

Purpose: Quantification of teeth is of clinical importance for various computer assisted procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries. In this regard, segmentation is a major step. Methods: In this paper, we propose a method for segmentation of teeth in volumetric computed tomography (CT) data using panoramic re-sampling of the dataset in the coronal view and variational level set. The proposed method consists of five steps as follows: first, we extract a mask in a CT images using Otsu thresholding. Second, the teeth are segmented from other bony tissues by utilizing anatomical knowledge of teeth in the jaws. Third, the proposed method is followed... 

Some of the most important classes of watermark detection methods in image watermarking are correlation-based algorithms. In these methods usually a pseudorandom noise pattern is embedded in the host image. The receiver can regenerate this pattern by having a key that is the seed of a random number generator. After that if the correlation between this pattern and the image that is assumed to have the watermark is higher than a predefined threshold, it means that the watermark exists and vice versa. Here, we show the advantage of using the Julian set patterns as a watermark, instead of the commonly used pseudorandom noise pattern. Julian set patterns can be regenerated in receiver with few... 

Motion estimation at fractional-pixel accuracy results in higher quality video sequences. However, the higher quality is achieved by more computations and increased required motion field bitrates. In this paper, new half-pixel accuracy block matching-based motion estimation algorithms are proposed to improve the rate-distortion characteristics of low-bitrate video communications. The proposed methods especially tend to decrease the required video bandwidth, with no degradation in quality of reconstructed image sequences. The key idea is to put a deeper focus on the origin (zero motion) based on the center-bias characteristics of low bitrate video motion fields. The experimental results show... 

This paper proposes two enhanced cross-diamond-hexagonal search algorithms to solve the motion-estimation problem in video coding. These algorithms differ from each other by their second step search only, and both of them employ cross-shaped pattern in first step. Proposed method is an improvement over CDHS, eliminating some checking points of CDHS algorithm. Experimental results show that the proposed methods perform faster than the diamond search (DS) and CDHS, whereas similar quality is preserved. © 2005 IEEE  

Radiographic inspection is one of the most appreciated techniques among non-destructive testing methods due to the production of a film which acts as a unique fingerprint record. Converting radiographs to a digital format and further digital image processing is the best method of enhancing the image quality and assisting the interpreter on his evaluation. In this research, different algorithms were used for image enhancement and radiograph interpretation in MATLAB environment. A graphical user interface (GUI) was created for implementation of different algorithms. Both spatial and frequency domains techniques were used for image enhancement. The main enhancement technique was a spatial... 

We extend the Watson image quality metric to 3D images through the concept of integral imaging. In the Watson's model, perceptual thresholds for changes to the DCT coefficients of a 2D image are given for information hiding. These thresholds are estimated in a way that the resulting distortion in the 2D image remains undetectable by the human eyes. In this paper, the same perceptual thresholds are estimated for a 3D scene in the integral imaging method. These thresholds are obtained based on the Watson's model using the relation between 2D elemental images and resulting 3D image. The proposed model is evaluated through subjective tests in a typical image steganography scheme  

Due to aging, circuit reliability has become extraordinary challenging. Reliability-aware circuit design flows do virtually not exist and even research is in its infancy. In this paper, we propose to bring aging awareness to EDA tool flows based on so-called degradation-aware cell libraries. These libraries include detailed delay information of gates/cells under the impact that aging has on both threshold voltage (Vth) and carrier mobility (μ) of transistors. This is unlike state of the art which considers Vth only. We show how ignoring μ degradation leads to underestimating guard-bands by 19% on average. Our investigation revealed that the impact of aging is strongly dependent on the...