scholarly journals Smoothing vs. sharpening of colour images: Together or separated

2017 ◽  
Vol 2 (1) ◽  
pp. 299-316 ◽  
Author(s):  
Cristina Pérez-Benito ◽  
Samuel Morillas ◽  
Cristina Jordán ◽  
J. Alberto Conejero

AbstractIt is still a challenge to improve the efficiency and effectiveness of image denoising and enhancement methods. There exists denoising and enhancement methods that are able to improve visual quality of images. This is usually obtained by removing noise while sharpening details and improving edges contrast. Smoothing refers to the case of denoising when noise follows a Gaussian distribution.Both operations, smoothing noise and sharpening, have an opposite nature. Therefore, there are few approaches that simultaneously respond to both goals. We will review these methods and we will also provide a detailed study of the state-of-the-art methods that attack both problems in colour images, separately.

2021 ◽  
pp. 4148-4157
Author(s):  
Nidhal Azawi

   Colonoscopy is a popular procedure which is used to detect an abnormality. Early diagnosis can help to heal many patients. The purpose of this paper is removing/reducing some artifacts to improve the visual quality of colonoscopy videos to provide better information for physicians. This work complements a series of work consisting of three previously published papers. In this paper, optic flow is used for motion compensation, where a number of consecutive images are registered to integrate some information to create a new image that has/reveals more information than the original one. Colon images were classified into informative and noninformative images by using a deep neural network. Then, two different strategies were used to treat informative and noninformative images. Informative images were treated by using Lucas Kanade with an adaptive temporal mean/median filter, whereas noninformative images were treated by using Lucas Kanade with a derivative of Gaussian (LKDOG) and adaptive temporal median images. Comparison showed that this work achieved better results than those achieved by the state-of-the-art strategies for the same degraded colon images data set. The new proposed algorithm reduced the error alignment by a factor of about 0.3, with a 100% successful image alignment ratio. In conclusion, this algorithm achieved better results than the state-of-the-art approaches in case of enhancing the informative images as shown in the results section; also, it helped to reveal some information from noninformative images that have very few details/no details.


Author(s):  
Mingliang Xu ◽  
Qingfeng Li ◽  
Jianwei Niu ◽  
Hao Su ◽  
Xiting Liu ◽  
...  

Quick response (QR) codes are usually scanned in different environments, so they must be robust to variations in illumination, scale, coverage, and camera angles. Aesthetic QR codes improve the visual quality, but subtle changes in their appearance may cause scanning failure. In this article, a new method to generate scanning-robust aesthetic QR codes is proposed, which is based on a module-based scanning probability estimation model that can effectively balance the tradeoff between visual quality and scanning robustness. Our method locally adjusts the luminance of each module by estimating the probability of successful sampling. The approach adopts the hierarchical, coarse-to-fine strategy to enhance the visual quality of aesthetic QR codes, which sequentially generate the following three codes: a binary aesthetic QR code, a grayscale aesthetic QR code, and the final color aesthetic QR code. Our approach also can be used to create QR codes with different visual styles by adjusting some initialization parameters. User surveys and decoding experiments were adopted for evaluating our method compared with state-of-the-art algorithms, which indicates that the proposed approach has excellent performance in terms of both visual quality and scanning robustness.


Author(s):  
Huan Vu ◽  
Samir Aknine ◽  
Sarvapali D. Ramchurn

Traffic congestion has a significant impact on quality of life and the economy. This paper presents a decentralised traffic management mechanism for intersections using a distributed constraint optimisation approach (DCOP). Our solution outperforms the state of the art solution both for stable traffic conditions (about 60% reduced waiting time) and robustness to unpredictable events. 


Author(s):  
Leonardo Silva Junior ◽  
Jéssica Andrade Vilas Boas ◽  
Marcos Eduardo Cordeiro Bernardes ◽  
Maria Inês Nogueira Alvarenga

Os processos ecológicos contribuem de forma ímpar para vivência humana, sendo capazes de fornecer condições essenciais à manutenção da vida na Terra, permitindo que ecossistemas se mantenham em equilíbrio. Nesse cenário, algumas áreas designadas legalmente pelo poder público, incubem-se de proteger vestígios naturais às ações antrópicas, porém estas áreas protegidas vêm sofrendo continuamente com pressões humanas mesmo em seus interiores. Assim, o Parque Estadual da Ilha Anchieta (PEIA), localizado no litoral norte do estado de São Paulo, é uma das áreas protegidas mais visitadas do estado. Nesse contexto, diversas atividades recreativas são permitidas em seu interior, possibilitando assim possíveis adversidades aos processos ecológicos. Assim, o objetivo deste trabalho foi avaliar a qualidade visual da paisagem do PEIA, por meio de indicadores ambientais. Para tal, foram selecionadas 10 paisagens de alta relevância quanto a sua beleza cênica, fluxo de turistas, amplitude visual, relevância educacional e para a conservação ambiental. As paisagens encontram-se em diferentes altitudes, fitofisionomias, aspectos abióticos e níveis de acesso público, com diversidade espacial, o que confere características únicas a elas. Os seguintes indicadores visuais foram usados na classificação das paisagens: diversidade; naturalidade; singularidade e detratores. Além disso, os locais foram georreferenciados e fotografados. Como resultado, quatro locais apresentaram qualidade visual média; quatro, com qualidade visual média superior e duas paisagens com qualidade visual superior. Em geral, a qualidade visual foi inferior nas zonas frontais do PEIA, onde o acesso aos turistas é facilitado por trilhas e infraestrutura de apoio. Já regiões mais afastadas e de difícil acesso foram as que apresentaram melhor qualidade visual. Deste modo, conclui-se que de fato a interferência humana reflete diretamente na qualidade visual das paisagens e assim, medidas de gestão ambiental, principalmente a atualização do seu plano de manejo, que data de 1989, podem dar suporte a uma proteção mais qualificada ao parque, bem como, proporcionar uma experiência ainda mais agradável e educativa aos seus visitantes. Quality visual landscape of State Park Anchieta Island, Ubatuba (SP, Brazil) ABSTRACT The ecological processes contribute in a unique way to human experience, being able to provide essential conditions for sustaining life on earth, allowing that keep ecosystems in balance. In this scenario, some areas legally designated by the Government, incubate up to protect natural traces to human actions, but these protected areas are continuously suffering from human pressures even in their interiors, Thus, the State Park of the Anchieta Island (PEIA), located on the northern coast of São Paulo, is one of the most visited protected areas of the state. In this context, various recreational activities are allowed inside, thus enabling possible adversities to ecological processes. Thus, the aim of this study was to evaluate the visual quality of PEIA landscape through environmental indicators. To this end, were selected 10 landscapes of high relevance as its scenic beauty, tourist flow, visual range, educational relevance and to environmental conservation. The landscapes are at different altitudes, vegetation types, abiotic aspects and public access levels with spatial diversity, which gives unique characteristics to them. The following visual indicators were used in the classification of landscapes: diversity; naturalness; uniqueness and detractors. Furthermore, the sites were georeferenced and photographed. As result, four sites had visual medium quality; four, with visual medium superior quality and two landscapes with visual superior quality. In general, the visual quality was lower in the frontal areas of the PEIA, where access to tourists is facilitated by trails and infrastructure support. Already more remote areas and difficult access showed the best visual quality. Thus, it is concluded that in fact human interference directly reflects the visual quality of the landscape and thus environmental management measures, mainly updating its management plan, dating from 1989 can support a more qualified protection park, as well as provide an experience even more enjoyable and educational visitors. KEYWORDS: Ecotourism; Protected Areas; Environmental Indicators.


2017 ◽  
Vol 108 (1) ◽  
pp. 307-318 ◽  
Author(s):  
Eleftherios Avramidis

AbstractA deeper analysis on Comparative Quality Estimation is presented by extending the state-of-the-art methods with adequacy and grammatical features from other Quality Estimation tasks. The previously used linear method, unable to cope with the augmented features, is replaced with a boosting classifier assisted by feature selection. The methods indicated show improved performance for 6 language pairs, when applied on the output from MT systems developed over 7 years. The improved models compete better with reference-aware metrics.Notable conclusions are reached through the examination of the contribution of the features in the models, whereas it is possible to identify common MT errors that are captured by the features. Many grammatical/fluency features have a good contribution, few adequacy features have some contribution, whereas source complexity features are of no use. The importance of many fluency and adequacy features is language-specific.


2022 ◽  
Vol 134 ◽  
pp. 103548
Author(s):  
Bianca Caiazzo ◽  
Mario Di Nardo ◽  
Teresa Murino ◽  
Alberto Petrillo ◽  
Gianluca Piccirillo ◽  
...  

Author(s):  
Muhammad Salman Raheel ◽  
Raad Raad

This chapter discusses the state of the art in dealing with the resource optimization problem for smooth delivery of video across a peer to peer (P2P) network. It further discusses the properties of using different video coding techniques such as Scalable Video Coding (SVC) and Multiple Descriptive Coding (MDC) to overcome the playback latency in multimedia streaming and maintains an adequate quality of service (QoS) among the users. The problem can be summarized as follows; Given that a video is requested by a peer in the network, what properties of SVC and MDC can be exploited to deliver the video with the highest quality, least upload bandwidth and least delay from all participating peers. However, the solution to these problems is known to be NP hard. Hence, this chapter presents the state of the art in approximation algorithms or techniques that have been proposed to overcome these issues.


Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3603
Author(s):  
Dasol Jeong ◽  
Hasil Park ◽  
Joongchol Shin ◽  
Donggoo Kang ◽  
Joonki Paik

Person re-identification (Re-ID) has a problem that makes learning difficult such as misalignment and occlusion. To solve these problems, it is important to focus on robust features in intra-class variation. Existing attention-based Re-ID methods focus only on common features without considering distinctive features. In this paper, we present a novel attentive learning-based Siamese network for person Re-ID. Unlike existing methods, we designed an attention module and attention loss using the properties of the Siamese network to concentrate attention on common and distinctive features. The attention module consists of channel attention to select important channels and encoder-decoder attention to observe the whole body shape. We modified the triplet loss into an attention loss, called uniformity loss. The uniformity loss generates a unique attention map, which focuses on both common and discriminative features. Extensive experiments show that the proposed network compares favorably to the state-of-the-art methods on three large-scale benchmarks including Market-1501, CUHK03 and DukeMTMC-ReID datasets.


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