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spatial Frequency and the Performance of Image-Based Visual complexity Metrics

IEEE ACCESS 2020年 8卷 100111-100119页

作者： Durmus, Dorukalp Penn State Univ Dept Architectural Engn University Pk PA 16802 USA

There is a wide range of visual and spatial complexity measurement methods that aim to quantify perceived image complexity. While image-based calculation methods (edge detection, image compression, contrast) characterize a digital image, visual perception studies focus on fundamental visual mechanisms, such as contrast sensitivity and visual task performance. Despite the evidence from several vision studies, spatial frequency information has not been widely utilized to assess image complexity. Previous studies suggest that image-based performance metrics are limited in explaining perceived complexity due to confounding factors, such as context, memory, familiarity, and expectation. Here, a visual experiment is conducted to assess the performance of image-based metrics and spatial frequency information using 16 abstract and natural images. A new image complexity metric (Rspt), based on detectability suprathreshold, was proposed to benchmark the performance of existing measures. Forty-four naive participants used a 5-point Likert-type scale to judge the visual complexity of the images displayed on a tablet. Results indicate that root-mean-square error (RMSE) and R spt correlate statistically signicantly with subjective evaluations. Biological sex did not affect perceived spatial complexity. While RMSE and R spt can potentially be used to estimate the spatial complexity of display images, the performance of spatial frequency information and image assessment measures in immersive viewing conditions require further research.

关键词： complexity theory Visualization Image coding Frequency measurement Sensitivity Gratings Digital images image analysis natural image statistics spatial complexity spatial frequency information

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Entropy, complexity, and spatial information

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JOURNAL OF GEOGRAPHICAL SYSTEMS 2014年第4期16卷 363-385页

作者： Batty, Michael Morphet, Robin Masucci, Paolo Stanilov, Kiril UCL Ctr Adv Spatial Anal London W1N 6TR England Martin Ctr Architectural & Urban Studies Dept Architecture Cambridge CB2 1PX England

We pose the central problem of defining a measure of complexity, specifically for spatial systems in general, city systems in particular. The measures we adopt are based on Shannon's (in Bell Syst Tech J 27:379-423, 623-656, 1948) definition of information. We introduce this measure and argue that increasing information is equivalent to increasing complexity, and we show that for spatial distributions, this involves a trade-off between the density of the distribution and the number of events that characterize it;as cities get bigger and are characterized by more events-more places or locations, information increases, all other things being equal. But sometimes the distribution changes at a faster rate than the number of events and thus information can decrease even if a city grows. We develop these ideas using various information measures. We first demonstrate their applicability to various distributions of population in London over the last 100 years, then to a wider region of London which is divided into bands of zones at increasing distances from the core, and finally to the evolution of the street system that characterizes the built-up area of London from 1786 to the present day. We conclude by arguing that we need to relate these measures to other measures of complexity, to choose a wider array of examples, and to extend the analysis to two-dimensional spatial systems.

关键词： Information Entropy Density spatial complexity London population London street system

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Shellogy: reading abalone shells to empower reef-scale management

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NEW ZEALAND JOURNAL OF MARINE AND FRESHWATER RESEARCH 2025年第1期59卷 263-282页

作者： Prince, Jeremy D. Biospherics Pty Ltd South Fremantle Australia

Developing spatially explicit assessment and management techniques that engage stakeholder behaviour has been an enduring priority for fisheries targeting benthic marine invertebrates like abalone. This study describes the basis of 'Shellogy';a concept with the potential to empower reef-scaled management by using shell morphology to qualitatively evaluate abalone populations and their variability. The premise of shellogy is that a range of shell characteristics, previously established as distinguishing between populations with differing life history parameters, are also indicative of relative age and stage of maturation. Using the analysis of existing data, literature synthesis and illustrations, together with simulation of length frequency histograms, this study establishes from first principles that the morphometric ratios of abalone shells, along with superficial internal and external shell characteristics, change predictably with age and maturation. This study explains how recognising the connection between shell shape, and relative age and maturity, enables the appearance of shells in populations and catches, to be used to inform qualitative reef-scale assessment and facilitate stakeholder engagement with reef-scale management initiatives.

关键词： Benthic invertebrate fisheries co-management facilitation haliotis morphometric marker phenotypic variability resource assessment small-scale fishery spatial complexity spawning potential ratio

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Multifractals of central place systems: Models, dimension spectrums, and empirical analysis

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PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 2014年 402卷 266-282页

作者： Chen, Yanguang Peking Univ Dept Geog Coll Urban & Environm Sci Beijing 100871 Peoples R China

Central place systems have been demonstrated to possess self-similarity in both the theoretical and empirical perspectives. A central place model can be treated as a monofractal with a single scaling process. However, a real system of human settlements is a complex network with multi-scaling processes. The simple fractal central place models are not enough to interpret the spatial patterns and evolutive processes of urban systems. It is necessary to construct multi-scaling fractal models of urban places. Based on the postulates of intermittent space filling and unequal probability of urban growth, two typical multifractal models of central places are proposed in this paper. One model is put forward to reflect the process of spatial concentration (convergence), and the generalized correlation dimension varies from 0.7306 to 1.3181;the other model is presented to describe the process of spatial deconcentration (divergence), the generalized correlation dimension ranges from 1.6523 to 1.7118. An empirical analysis was made by the cities and towns of Central Plains, China, and an analogy is drawn between the real system of urban places and the theoretical models. A finding is that urban systems take on multifractal form, and can be modeled with multi-scaling fractals. This is a preliminary attempt to develop the theory of fractal central places, and the results are helpful for understanding the similarities and differences between the dynamical process of spatial concentration and that of spatial deconcentration. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Central places Self-organized network of cities Multifractals Singularity spectrum spatial complexity Chinese cities

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Content-adaptive bitstream-layer model for coding distortion assessment of H.264/AVC networked video

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2014年第5期25卷 1199-1208页

作者： Su, Honglei Yang, Fuzheng Xidian Univ State Key Lab Integrated Serv Networks Xian Peoples R China

Bitstream-layer models are designed to use the information extracted from both packet headers and payload for real-time and non-intrusive quality monitoring of networked video. This paper proposes a content-adaptive bitstream-layer (CABL) model for coding distortion assessment of H.264/AVC networked video. Firstly, the fundamental relationship between perceived coding distortion and quantization parameter (QP) is established. Then, considering the fact that the perceived coding distortion of a networked video significantly relies on both the spatial and temporal characteristics of video content, spatial and temporal complexities are incorporated in the proposed model. Assuming that the residuals before Discrete Cosine Transform (DCT) keep to the Laplace distribution, the scale parameters of the Laplace distribution are estimated utilizing QP and quantized coefficients on the basis of the Parseval theorem firstly. Then the spatial complexity is evaluated using QP and the scale parameters. Meanwhile, the temporal complexity is obtained using the weighted motion vectors (MV) considering the variations in temporal masking extent for high motion regions and low motion regions, respectively. Both the two characteristics of video content are extracted from the compressed bitstream without resorting to a complete decoding. Using content related information, the proposed model is able to adapt to different video contents. Experimental results show that the overall performance of CABL model significantly outperforms that of the P.1202.1 model and other coding distortion assessment models in terms of widely used performance criteria, including the Pearson Correlation Coefficient (PCC), the Spearman Rank Order Correlation Coefficient (SROCC), the Root-Mean-Squared Error (RMSE) and the Outlier Ratio (OR). (c) 2014 Elsevier Inc. All rights reserved.

关键词： No reference Video quality assessment Bitstream-layer model Coding distortion H.264/AVC Networked video spatial complexity Temporal complexity

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Spatio-ecological complexity measures in GRASS GIS

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COMPUTERS & GEOSCIENCES 2017年 104卷 166-176页

作者： Rocchini, Duccio Petras, Vaclav Petrasova, Anna Chemin, Yann Ricotta, Carlo Frigeri, Alessandro Landa, Martin Marcantonio, Matteo Bastin, Lucy Metz, Markus Delucchi, Luca Neteler, Markus Fdn Edmund Mach Dept Biodivers & Mol Ecol Res & Innovat Ctr Via E Mach 1 I-38010 San Michele All Adige TN Italy North Carolina State Univ Dept Marine Earth & Atmospher Sci 2800 Faucette Dr Raleigh NC 27695 USA North Carolina State Univ Ctr Geospatial Analyt 2800 Faucette Dr Raleigh NC 27695 USA IWMI Res Div Pelawatta Sri Lanka Univ Roma La Sapienza Dept Environm Biol I-00185 Rome Italy IAPS Ist Nazl Astrofis INAF Via Fosso Cavaliere 100 I-00133 Rome Italy Czech Tech Univ Dept Geomat Prague 16629 Czech Republic Tech Univ Berlin Geoinformat Environm Planning Lab Berlin Germany Aston Univ Sch Comp Sci Birmingham W Midlands England Mundialis GmbH & Co KG Kolnstr 99 D-53111 Bonn Germany European Commiss Joint Res Ctr Brussels Belgium

Good estimates of ecosystem complexity are essential for a number of ecological tasks: from biodiversity estimation, to forest structure variable retrieval, to feature extraction by edge detection and generation of multifractal surface as neutral models for e.g. feature change assessment. Hence, measuring ecological complexity over space becomes crucial in macroecology and geography. Many geospatial tools have been advocated in spatial ecology to estimate ecosystem complexity and its changes over space and time. Among these tools, free and open source options especially offer opportunities to guarantee the robustness of algorithms and reproducibility. In this paper we will summarize the most straightforward measures of spatial complexity available in the Free and Open Source Software GRASS GIS, relating them to key ecological patterns and processes. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Free and Open Source Software Remote sensing spatial complexity spatial ecology

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Study of clay-organic complexes

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CURRENT SCIENCE 2010年第7期98卷 915-921页

作者： Manjaiah, K. M. Kumar, Sarvendra Sachdev, M. S. Sachdev, P. Datta, S. C. Indian Agr Res Inst Div Soil Sci & Agr Chem New Delhi 110012 India Indian Agr Res Inst Nucl Res Lab New Delhi 110012 India

The union of clay minerals and organic substances in soil to form clay-organic complex is a synthesis as vital to continuance of life and as less understood as photosynthesis. The X-ray spectromicroscopy technique has enabled the identification of spatial variability of organic matter forms. Synchrotron-based near-edge X-ray spectromicroscopy of thin sections of entire and intact free organo-mineral microaggregates are able to demonstrate on spatial scales below 50 nm resolution. The zonal concept of clay-organic interactions offers a new basis for understanding and predicting the retention of organic compounds, including contaminants, in soils and sediments. Combination of atomic/molecular structural data and energy derivatives opens up new insights into binding sites and transport forms between biological and/or xenobiotic substances and soil organic matter. Therefore, understanding the mechanism/processes of formation and properties of clay-organic complexes may facilitate development of agricultural management systems that increase long-term C stability or sequestration in soils.

关键词： Clay-organic complex molecular modelling spatial complexity X-ray microscopy zonal model

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IMPLICIT O(1) PROBE SEARCH

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SIAM JOURNAL ON COMPUTING 1993年第1期22卷 1-10页

作者： FIAT, A NAOR, M UNIV CALIF BERKELEY BERKELEYCA 94720 IBM CORP DIV RESALMADEN RES CTR650 HARRY RDSAN JOSECA 95120

Given a set of n elements from the domain {1,..., m}, this paper investigates how to arrange them in a table of size n, so that searching for an element in the table can be done in constant time. Yao [J. Assoc. Comput. Mach., 28(1981), pp. 615-628] has shown that this cannot be done when the domain is sufficiently large as a function of n. This paper gives a constructive solution when the domain m is polynomial in n, the number of elements, as well as a nonconstructive proof for m no larger than exponential in poly (n). The authors improve upon a result of Yao and give better bounds on the maximum m for which implicit O(1) probe search can be done. The results are achieved by showing the tight relationship between hashing and certain encoding problems called rainbows.

关键词： HASHING PERFECT HASHING spatial complexity RAMSEY THEORY RANDOMNESS IN COMPUTATION

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Influence of calcination temperature on the 3D nanoscale topography of LaMnO3 thin films: A comprehensive surface analysis

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CERAMICS INTERNATIONAL 2024年第21期50卷 41747-41760页

作者： da Silva, Alexandre Souza Romaguera-Barcelay, Yonny Matos, Robert S. Das, Abhijeet Gandarilla, Ariamna Brito, Walter Ricardo da Fonseca Filho, Henrique Duarte Univ Fed Amazonas UFAM Programa Posgrad Fis PPGFIS BR-69067005 Manaus AM Brazil Univ Fed Amazonas Dept Mat Phys Lab Desenvolvimento & Aplicaco Nanomat Amazonia LA BR-69067005 Manaus AM Brazil Univ Fed Amazonas Dept Chem Lab Bioelet & Eletroanalit LABEL BR-69067005 Manaus AM Brazil Univ Coimbra Fac Sci & Technol Dept Chem Engn CEEMPRE ARISEBioMarkUC Coimbra Portugal Indian Inst Sci Dept Bioengn Bangalore 560012 India

In this paper, we present a comprehensive study on the 3D nanoscale topography of LaMnO3 thin films, focusing on the influence of calcination temperature on surface morphology. The study reveals significant structural, chemical, and morphological changes as a function of the calcination temperature. XRD analysis confirmed the formation of the orthorhombic LaMnO3 structure at 700 degrees C, 750 degrees C, and 800 degrees C, with increasing unit cell volume and crystallite size observed at higher temperatures. FTIR spectra identified characteristic functional groups associated with molecular vibrations, indicating the perovskite structure. SEM imaging showed grain growth with temperature, while EDS analysis confirmed compound formation and substrate interactions. AFM analysis revealed increased surface roughness with temperature, attributed to nucleation and crystal growth. Morphological and microtextural analyses further detailed changes in surface features, peaks, valleys, and voids. Fractal characterization highlighted variations in surface texture with temperature, with a decrease in dominant wavelength indicating changes in microtexture complexity. Overall, the findings provide insights into the temperature-dependent properties of LaMnO3 thin films, essential for optimizing growth conditions and understanding their potential applications in various fields.

关键词： LaMnO 3, thin films Structure Nanoscale topography spatial complexity

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Energy-Aware spatial and Temporal Resolution Selection for Per-Title Encoding

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IEEE ACCESS 2024年 12卷 104555-104567页

作者： Ghasempour, Mohammad Amirpour, Hadi Timmerer, Christian Alpen Adria Univ Klagenfurt Christian Doppler Lab ATHENA A-9020 Klagenfurt Austria

Video streaming has become an integral part of our digital lives, driving the need for efficient video delivery. With the growing demand for seamless video delivery, adaptive video streaming has emerged as a solution to support users with varying device capabilities and network conditions. Traditional adaptive streaming relies on a predetermined set of bitrate-resolution pairs, known as bitrate ladders, for encoding. However, this "one-size-fits-all" approach is suboptimal when dealing with diverse video content. Consequently, per-title encoding approaches dynamically select the bitrate ladder for each content. However, in an era when carbon dioxide emissions have become a paramount concern, it is crucial to consider energy consumption. Therefore, this paper addresses the pressing issue of increasing energy consumption in video streaming by introducing a novel approach, ESTR, which goes beyond traditional quality-centric resolution selection approaches. Instead, the ESTR considers both video quality and decoding energy consumption to construct an optimal bitrate ladder tailored to the unique characteristics of each video content. To accomplish this, ESTR encodes each video content using a range of spatial and temporal resolutions, each paired with specific bitrates. It then establishes a maximum acceptable quality drop threshold (tau ), carefully selecting resolutions that not only preserve video quality above this threshold but also minimize decoding energy consumption. Our experimental results, at a fixed tau of 2 VMAF steps, demonstrate a 32.87% to 41.86% reduction in decoding energy demand for HEVC-encoded videos across various software decoder implementations and operating systems, with a maximum bitrate increase of 2.52%. Furthermore, on a hardware-accelerated client device, a 46.37% energy saving was achieved during video playback at the expense of a 2.52% bitrate increase. Remarkably, these gains in energy efficiency are achieved while maintaining consistent

关键词： Bit rate Streaming media Decoding Encoding Energy resolution spatial resolution Energy consumption Video streaming spatial complexity temporal complexity per-title encoding HEVC VVC

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