Accedi

Bibliografie tematiche / JPEG (Image coding standard); image processing / Tesi

Segui questo link per vedere altri tipi di pubblicazioni sul tema: JPEG (Image coding standard); image processing.

Tesi sul tema "JPEG (Image coding standard); image processing"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 7 febbraio 2022

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Vedi i top-36 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "JPEG (Image coding standard); image processing".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.

1

Gupta, Amit Kumar Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Hardware optimization of JPEG2000". Awarded by:University of New South Wales. School of Electrical Engineering and Telecommunications, 2006. http://handle.unsw.edu.au/1959.4/30581.

Testo completo

Abstract (sommario):

The Key algorithms of JPEG2000, the new image compression standard, have high computational complexity and thus present challenges for efficient implementation. This has led to research on the hardware optimization of JPEG2000 for its efficient realization. Luckily, in the last century the growth in Microelectronics allows us to realize dedicated ASIC solutions as well as hardware/software FPGA based solutions for complex algorithms such as JPEG2000. But an efficient implementation within hard constraints of area and throughput, demands investigations of key dependencies within the JPEG2000 system. This work presents algorithms and VLSI architectures to realize a high performance JPEG2000 compression system. The embedded block coding algorithm which lies at the heart of a JPEG2000 compression system is a main contributor to enhanced JPEG2000 complexity. This work first concentrates on algorithms to realize low-cost high throughput Block Coder (BC) system. For this purpose concurrent symbol processing capable Bit Plane Coder architecture is presented. Further optimal 2 sub-bank memory and an efficient buffer architectures are designed to keep the hardware cost low. The proposed overall BC system presents the highest Figure Of Merit (FOM) in terms of throughput versus hardware cost in comparison to existing BC solutions. Further, this work also investigates the challenges involved in the efficient integration of the BC with the overall JPEG2000 system. A novel low-cost distortion estimation approach with near-optimal performance is proposed which is necessary for accurate rate-control performance of JPEG2000. Additionally low bandwidth data storage and transfer techniques are proposed for efficient transfer of subband samples to the BC. Simulation results show that the proposed techniques have approximately 4 times less bandwidth than existing architectures. In addition, an efficient high throughput block decoder architecture based on the proposed selective sample-skipping algorithm is presented. The proposed architectures are designed and analyzed on both ASIC and FPGA platforms. Thus, the proposed algorithms, architectures and efficient BC integration strategies are useful for realizing a dedicated ASIC JPEG2000 system as well as a hardware/software FPGA based JPEG2000 solution. Overall this work presents algorithms and architectures to realize a high performance JPEG2000 system without imposing any restrictions in terms of coding modes or block size for the BC system.

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Nolte, Ernst Hendrik. "Image compression quality measurement : a comparison of the performance of JPEG and fractal compression on satellite images". Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51796.

Testo completo

Abstract (sommario):

Thesis (MEng)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: The purpose of this thesis is to investigate the nature of digital image compression and the calculation of the quality of the compressed images. The work is focused on greyscale images in the domain of satellite images and aerial photographs. Two compression techniques are studied in detail namely the JPEG and fractal compression methods. Implementations of both these techniques are then applied to a set of test images. The rest of this thesis is dedicated to investigating the measurement of the loss of quality that was introduced by the compression. A general method for quality measurement (signal To Noise Ratio) is discussed as well as a technique that was presented in literature quite recently (Grey Block Distance). Hereafter, a new measure is presented. After this, a means of comparing the performance of these measures is presented. It was found that the new measure for image quality estimation performed marginally better than the SNR algorithm. Lastly, some possible improvements on this technique are mentioned and the validity of the method used for comparing the quality measures is discussed.
AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om ondersoek in te stel na die aard van digitale beeldsamepersing en die berekening van beeldkwaliteit na samepersing. Daar word gekonsentreer op grysvlak beelde in die spesifieke domein van satellietbeelde en lugfotos. Twee spesifieke samepersingstegnieke word in diepte ondersoek naamlik die JPEG en fraktale samepersingsmetodes. Implementasies van beide hierdie tegnieke word op 'n stel toetsbeelde aangewend. Die res van hierdie tesis word dan gewy aan die ondersoek van die meting van die kwaliteitsverlies van hierdie saamgeperste beelde. Daar word gekyk na 'n metode wat in algemene gebruik in die praktyk is asook na 'n nuwer metode wat onlangs in die literatuur veskyn het. Hierna word 'n nuwe tegniek bekendgestel. Verder word daar 'n vergelyking van hierdie mates en 'n ondersoek na die interpretasie van die 'kwaliteit' van hierdie kwaliteitsmate gedoen. Daar is gevind dat die nuwe maatstaf vir kwaliteit net so goed en selfs beter werk as die algemene maat vir beeldkwaliteit naamlik die Sein tot Ruis Verhouding. Laastens word daar moontlike verbeterings op die maatstaf genoem en daar volg 'n bespreking oor die geldigheid van die metode wat gevolg is om die kwaliteit van die kwaliteitsmate te bepaal

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Samuel, Sindhu. "Digital rights management (DRM) : watermark encoding scheme for JPEG images". Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-09122008-182920/.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Natu, Ambarish Shrikrishna Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Error resilience in JPEG2000". Awarded by:University of New South Wales. Electrical Engineering and Telecommunications, 2003. http://handle.unsw.edu.au/1959.4/18835.

Testo completo

Abstract (sommario):

The rapid growth of wireless communication and widespread access to information has resulted in a strong demand for robust transmission of compressed images over wireless channels. The challenge of robust transmission is to protect the compressed image data against loss, in such a way as to maximize the received image quality. This thesis addresses this problem and provides an investigation of a forward error correction (FEC) technique that has been evaluated in the context of the emerging JPEG2000 standard. Not much effort has been made in the JPEG2000 project regarding error resilience. The only techniques standardized are based on insertion of marker codes in the code-stream, which may be used to restore high-level synchronization between the decoder and the code-stream. This helps to localize error and prevent it from propagating through the entire code-stream. Once synchronization is achieved, additional tools aim to exploit as much of the remaining data as possible. Although these techniques help, they cannot recover lost data. FEC adds redundancy into the bit-stream, in exchange for increased robustness to errors. We investigate unequal protection schemes for JPEG2000 by applying different levels of protection to different quality layers in the code-stream. More particularly, the results reported in this thesis provide guidance concerning the selection of JPEG2000 coding parameters and appropriate combinations of Reed-Solomon (RS) codes for typical wireless bit error rates. We find that unequal protection schemes together with the use of resynchronization makers and some additional tools can significantly improve the image quality in deteriorating channel conditions. The proposed channel coding scheme is easily incorporated into the existing JPEG2000 code-stream structure and experimental results clearly demonstrate the viability of our approach

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Muller, Rikus. "A study of image compression techniques, with specific focus on weighted finite automata". Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1128.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Chien, Chi-Hao. "A comparison study of the implementation of digital camera's RAW and JPEG and scanner's TIFF file formats, and color management procedures for inkjet textile printing applications /". Online version of thesis, 2009. http://hdl.handle.net/1850/10886.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Kailasanathan, Chandrapal. "Securing digital images". Access electronically, 2003. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20041026.150935/index.html.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Yeung, Yick Ming. "Fast rate control for JPEG2000 image coding /". View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20YEUNG.

Testo completo

Abstract (sommario):

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.
Includes bibliographical references (leaves 63-65). Also available in electronic version. Access restricted to campus users.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Giakoumakis, Michail D. "Refinements in a DCT based non-uniform embedding watermarking scheme". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FGiakoumakis.pdf.

Testo completo

Abstract (sommario):

Thesis (M.S. in Applied Math and M.S. in Systems Engineering)--Naval Postgraduate School, March 2003.
Thesis advisor(s): Roberto Cristi, Ron Pieper, Craig Rasmussen. Includes bibliographical references (p. 119-121). Also available online.

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Kamaras, Konstantinos. "JPEG2000 image compression and error resilience for transmission over wireless channels". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://sirsi.nps.navy.mil/uhtbin/hyperion-image/02Mar%5FKamaras.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Thorpe, Christopher. "Compression aided feature based steganalysis of perturbed quantization steganography in JPEG images". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 114 p, 2008. http://proquest.umi.com/pqdweb?did=1459914021&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Pao, I.-Ming. "Improved standard-conforming video coding techniques /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/5936.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Frandina, Peter. "VHDL modeling and synthesis of the JPEG-XR inverse transform /". Online version of thesis, 2009. http://hdl.handle.net/1850/10755.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Chan, Syin. "The use of the JPEG image compression standard and the problems of recompression". Thesis, University of Kent, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316248.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Uehara, Takeyuki. "Contributions to image encryption and authentication". Access electronically, 2003. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20040920.124409/index.html.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Choi, Kai-san. "Automatic source camera identification by lens aberration and JPEG compression statistics". Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B38902345.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Choi, Kai-san, e 蔡啟新. "Automatic source camera identification by lens aberration and JPEG compression statistics". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38902345.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Xin, Jun. "Improved standard-conforming video transcoding techniques /". Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/5871.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Dyer, Michael Ian Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Hardware Implementation Techniques for JPEG2000". Awarded by:University of New South Wales. Electrical Engineering and Telecommunications, 2007. http://handle.unsw.edu.au/1959.4/30510.

Testo completo

Abstract (sommario):

JPEG2000 is a recently standardized image compression system that provides substantial improvements over the existing JPEG compression scheme. This improvement in performance comes with an associated cost in increased implementation complexity, such that a purely software implementation is inefficient. This work identifies the arithmetic coder as a bottleneck in efficient hardware implementations, and explores various design options to improve arithmetic coder speed and size. The designs produced improve the critical path of the existing arithmetic coder designs, and then extend the coder throughput to 2 or more symbols per clock cycle. Subsequent work examines more system level implementation issues. This work examines the communication between hardware blocks and utilizes certain modes of operation to add flexibility to buffering solutions. It becomes possible to significantly reduce the amount of intermediate buffering between blocks, whilst maintaining a loose synchronization. Full hardware implementations of the standard are necessarily limited in the amount of features that they can offer, in order to constrain complexity and cost. To circumvent this, a hardware / software codesign is produced using the Altera NIOS II softcore processor. By keeping the majority of the standard implemented in software and using hardware to accelerate those time consuming functions, generality of implementation can be retained, whilst implementation speed is improved. In addition to this, there is the opportunity to explore parallelism, by providing multiple identical hardware blocks to code multiple data units simultaneously.

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Muller, Rikus. "Applying the MDCT to image compression". Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1197.

Testo completo

Abstract (sommario):

Thesis (DSc (Mathematical Sciences. Applied Mathematics))--University of Stellenbosch, 2009.
The replacement of the standard discrete cosine transform (DCT) of JPEG with the windowed modifed DCT (MDCT) is investigated to determine whether improvements in numerical quality can be achieved. To this end, we employ an existing algorithm for optimal quantisation, for which we also propose improvements. This involves the modelling and prediction of quantisation tables to initialise the algorithm, a strategy that is also thoroughly tested. Furthermore, the effects of various window functions on the coding results are investigated, and we find that improved quality can indeed be achieved by modifying JPEG in this fashion.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Gatica, Perez Daniel. "Extensive operators in lattices of partitions for digital video analysis /". Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/5874.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Meng, Bojun. "Efficient intra prediction algorithm in H.264 /". View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20MENG.

Testo completo

Abstract (sommario):

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.
Includes bibliographical references (leaves 66-68). Also available in electronic version. Access restricted to campus users.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Lucero, Aldo. "Compressing scientific data with control and minimization of the L-infinity metric under the JPEG 2000 framework". To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Kang, James M. "A query engine of novelty in video streams /". Link to online version, 2005. https://ritdml.rit.edu/dspace/handle/1850/977.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Pevný, Tomáš. "Kernel methods in steganalysis". Diss., Online access via UMI:, 2008.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Zitzmann, Cathel. "Détection statistique d'information cachée dans des images naturelles". Thesis, Troyes, 2013. http://www.theses.fr/2013TROY0012/document.

Testo completo

Abstract (sommario):

La nécessité de communiquer de façon sécurisée n’est pas chose nouvelle : depuis l’antiquité des méthodes existent afin de dissimuler une communication. La cryptographie a permis de rendre un message inintelligible en le chiffrant, la stéganographie quant à elle permet de dissimuler le fait même qu’un message est échangé. Cette thèse s’inscrit dans le cadre du projet "Recherche d’Informations Cachées" financé par l’Agence Nationale de la Recherche, l’Université de Technologie de Troyes a travaillé sur la modélisation mathématique d’une image naturelle et à la mise en place de détecteurs d’informations cachées dans les images. Ce mémoire propose d’étudier la stéganalyse dans les images naturelles du point de vue de la décision statistique paramétrique. Dans les images JPEG, un détecteur basé sur la modélisation des coefficients DCT quantifiés est proposé et les calculs des probabilités du détecteur sont établis théoriquement. De plus, une étude du nombre moyen d’effondrements apparaissant lors de l’insertion avec les algorithmes F3 et F4 est proposée. Enfin, dans le cadre des images non compressées, les tests proposés sont optimaux sous certaines contraintes, une des difficultés surmontées étant le caractère quantifié des données
The need of secure communication is not something new: from ancient, methods exist to conceal communication. Cryptography helped make unintelligible message using encryption, steganography can hide the fact that a message is exchanged.This thesis is part of the project "Hidden Information Research" funded by the National Research Agency, Troyes University of Technology worked on the mathematical modeling of a natural image and creating detectors of hidden information in digital pictures.This thesis proposes to study the steganalysis in natural images in terms of parametric statistical decision. In JPEG images, a detector based on the modeling of quantized DCT coefficients is proposed and calculations of probabilities of the detector are established theoretically. In addition, a study of the number of shrinkage occurring during embedding by F3 and F4 algorithms is proposed. Finally, for the uncompressed images, the proposed tests are optimal under certain constraints, a difficulty overcome is the data quantization

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Jamrozik, Michele Lynn. "Spatio-temporal segmentation in the compressed domain". Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/15681.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Beltrão, Gabriel Tedgue. "Rápida predição da direção do bloco para aplicação com transformadas direcionais". [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260075.

Testo completo

Abstract (sommario):

Orientadores: Yuzo Iano, Rangel Arthur
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-21T22:39:06Z (GMT). No. of bitstreams: 1 Beltrao_GabrielTedgue_M.pdf: 7074938 bytes, checksum: 0a2d464733f2fb5dcc14430cc1844758 (MD5) Previous issue date: 2012
Resumo: As transformadas derivadas da DCT são amplamente utilizadas para compressão de vídeo. Recentemente, muitos autores têm destacado que os resíduos de predição normalmente apresentam estruturas direcionais que não podem ser eficientemente representadas pela DCT convencional. Nesse contexto, muitas transformadas direcionais têm sido propostas como forma de suplantar a deficiência da DCT em lidar com tais estruturas. Apesar do desempenho superior das transformadas direcionais sobre a DCT convencional, para a sua aplicação na compressão de vídeo é necessário avaliar o aumento no tempo de codificação e a complexidade para sua implementação. Este trabalho propõe um rápido algoritmo para se estimar as direções existentes em um bloco antes da aplicação das transformadas direcionais. O codificador identifica as direções predominantes em cada bloco e aplica apenas a transformada referente àquela direção. O algoritmo pode ser usado em conjunto com qualquer proposta de transformadas direcionais que utilize a técnica de otimização por taxa-distorção (RDO) para a seleção da direção a ser explorada, reduzindo a complexidade de implementação a níveis similares a quando apenas a DCT convencional é utilizada
Abstract: DCT-based transforms are widely adopted for video compression. Recently, many authors have highlighted that prediction residuals usually have directional structures that cannot be efficiently represented by conventional DCT. In this context, many directional transforms have been proposed as a way to overcome DCT's deficiency in dealing with such structures. Although directional transforms have superior performance over the conventional DCT, for application in video compression it is necessary to evaluate increase in coding time and complexity for its implementation. This work proposes a fast algorithm for estimating blocks directions before applying directional transforms. The encoder identifies predominant directions in each block, and only applies the transform referent to that direction. The algorithm can be used in conjunction with any proposed algorithm for directional transforms that uses the rate-distortion optimization (RDO) process for selection of the direction to be explored; reducing implementation complexity to similar levels when only conventional DCT is used
Mestrado
Telecomunicações e Telemática
Mestre em Engenharia Elétrica

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Almeida, Junior Jurandy Gomes de 1983. "Recuperação de vídeos comprimidos por conteúdo". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275706.

Testo completo

Abstract (sommario):

Orientador: Ricardo da Silva Torres
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação
Made available in DSpace on 2018-08-19T18:14:01Z (GMT). No. of bitstreams: 1 AlmeidaJunior_JurandyGomesde_D.pdf: 7003455 bytes, checksum: 9f2b66a600d6b6ae595b02265ceb1585 (MD5) Previous issue date: 2011
Resumo: Avanços recentes na tecnologia têm permitido o aumento da disponibilidade de dados de vídeo, criando grandes coleções de vídeo digital. Isso tem despertado grande interesse em sistemas capazes de gerenciar esses dados de forma eficiente. Fazer uso eficiente de informações de vídeo requer o desenvolvimento de ferramentas poderosas capazes de extrair representações semânticas de alto nível a partir de características de baixo nível do conteúdo de vídeo. Devido à complexidade desse material, existem cinco desafios principais na concepção de tais sistemas: (1) dividir o fluxo de vídeo em trechos manuseáveis de acordo com a sua estrutura de organização, (2) implementar algoritmos para codificar as propriedades de baixo nível de um trecho de vídeo em vetores de características, (3) desenvolver medidas de similaridade para comparar esses trechos a partir de seus vetores, (4) responder rapidamente a consultas por similaridade sobre uma enorme quantidade de sequências de vídeo e (5) apresentar os resultados de forma amigável a um usuário. Inúmeras técnicas têm sido propostas para atender a tais requisitos. A maioria dos trabalhos existentes envolve algoritmos e métodos computacionalmente custosos, em termos tanto de tempo quanto de espaço, limitando a sua aplicação apenas ao ambiente acadêmico e/ou a grandes empresas. Contrário a essa tendência, o mercado tem mostrado uma crescente demanda por dispositivos móveis e embutidos. Nesse cenário, é imperativo o desenvolvimento de técnicas tanto eficazes quanto eficientes a fim de permitir que um público maior tenha acesso a tecnologias modernas. Nesse contexto, este trabalho apresenta cinco abordagens originais voltadas a análise, indexação e recuperação de vídeos digitais. Todas essas contribuições são somadas na construção de um sistema de gestão de vídeos por conteudo computacionalmente rápido, capaz de atingir a um padrão de qualidade similar, ou até mesmo superior, a soluções atuais
Abstract: Recent advances in the technology have enabled the increase of the availability of video data, creating large digital video collections. This has spurred great interest in systems that are able to manage those data in a efficient way. Making efficient use of video information requires the development of powerful tools to extract high-level semantics from low-level features of the video content. Due to the complexity of the video material, there are five main challenges in designing such systems: (1) to divide the video stream into manageable segments according to its organization structure; (2) to implement algorithms for encoding the low-level features of each video segment into feature vectors; (3) to develop similarity measures for comparing these segments by using their feature vectors; (4) to quickly answer similarity queries over a huge amount of video sequences; and (5) to present the list of results in a user-friendly way. Numerous techniques have been proposed to support such requirements. Most of existing works involve algorithms and methods which are computationally expensive, in terms of both time and space, limiting their application to the academic world and/or big companies. Contrary to this trend, the market has shown a growing demand for mobile and embedded devices. In this scenario, it is imperative the development of techniques so effective as efficient in order to allow more people have access to modern technologies. In this context, this work presents five novel approaches for the analysis, indexing, and retrieval of digital videos. All these contributions are combined to create a computationally fast system for content-based video management, which is able to achieve a quality level similar, or even superior, to current solutions
Doutorado
Ciência da Computação
Doutor em Ciência da Computação

Gli stili APA, Harvard, Vancouver, ISO e altri

30

"The effects of evaluation and rotation on descriptors and similarity measures for a single class of image objects". Thesis, 2008. http://hdl.handle.net/10210/564.

Testo completo

Abstract (sommario):

“A picture is worth a thousand words”. If this proverb were taken literally we all know that every person interprets images or photos differently in terms of its content. This is due to the semantics contained in these images. Content-based image retrieval has become a vast area of research in order to successfully describe and retrieve images according to the content. In military applications, intelligence images such as those obtained by the defence intelligence group are taken (mostly on film), developed and then manually annotated thereafter. These photos are then stored in a filing system according to certain attributes such as the location, content etc. To retrieve these images at a later stage might take days or even weeks to locate. Thus, the need for a digital annotation system has arisen. The images of the military contain various military vehicles and buildings that need to be detected, described and stored in a database. For our research we want to look at the effects that the rotation and elevation angle of an object in an image has on the retrieval performance. We chose model cars in order to be able to control the environment the photos were taken in such as the background, lighting, distance between the objects, and the camera etc. There are also a wide variety of shapes and colours of these models to obtain and work with. We look at the MPEG-7 descriptor schemes that are recommended by the MPEG group for video and image retrieval as well as implement three of them. For the military it could be required that when the defence intelligence group is in the field, that the images be directly transmitted via satellite to the headquarters. We have therefore included the JPEG2000 standard which gives a compression performance increase of 20% over the original JPEG standard. It is also capable to transmit images wirelessly as well as securely. Including the MPEG-7 descriptors that we have implemented, we have also implemented the fuzzy histogram and colour correlogram descriptors. For our experimentation we implemented a series of experiments in order to determine the effects that rotation and elevation has on our model vehicle images. Observations are made when each vehicle is considered separately and when the vehicles are described and combined into a single database. After the experiments are done we look at the descriptors and determine which adjustments could be made in order to improve the retrieval performance thereof.
Dr. W.A. Clarke

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Natu, Ambarish Shrikrishna. "Error resilience in JPEG2000 /". 2003. http://www.library.unsw.edu.au/~thesis/adt-NUN/public/adt-NUN20030519.163058/index.html.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Sevcenco, Ana-Maria. "Adaptive strategies and optimization techniques for JPEG-based low bit-rate image coding". Thesis, 2007. http://hdl.handle.net/1828/2282.

Testo completo

Abstract (sommario):

The field of digital image compression has been intensively explored to obtain ever improved performance corresponding to a given bit budget. The DCT-based JPEG standard remains to be one of the most popular image compression standards due to its reasonable coding performance, fast implementations, friendly low-cost architecture. flexibility and adaptivity on block level. In this thesis, we consider the problem of low bit-rate image coding and present new approaches using adaptive strategies and optimization techniques for performance enhancement, while employing the DCT block-based JPEG standard as the main framework with several pre- and post-processing , steps. We propose an adaptive coding approach which involves a variable quality factor in the quantization step of JPEG compression to make the compression more flexible in respect to bit budget requirements. We also propose an adaptive sampling approach based on variable down-'up-scaling rate and local image characteristics. In addition. we study an adaptive filtering approach in which the optimal filters coefficients are determined by making use of optimization methods and symmetric extension techniques. Simulation results are presented to demonstrate the effectiveness of the proposed techniques relative to recent works in the field of low bit-rate image coding.

Gli stili APA, Harvard, Vancouver, ISO e altri

33

"Object-based scalable wavelet image and video coding". Thesis, 2008. http://library.cuhk.edu.hk/record=b6074669.

Testo completo

Abstract (sommario):

The first part of this thesis studies advanced wavelet transform techniques for scalable still image object coding. In order to adapt to the content of a given signal and obtain more flexible adaptive representation, two advanced wavelet transform techniques, wavelet packet transform and directional wavelet transform, are developed for object-based image coding. Extensive experiments demonstrate that the new wavelet image coding systems perform comparable to or better than state-of-the-art in image compression while possessing some attractive features such as object-based coding functionality and high coding scalability.
The objective of this thesis is to develop an object-based coding framework built upon a family of wavelet coding techniques for a variety of arbitrarily shaped visual object scalable coding applications. Two kinds of arbitrarily shaped visual object scalable coding techniques are investigated in this thesis. One is object-based scalable wavelet still image coding; another is object-based scalable wavelet video coding.
The second part of this thesis investigates various components of object-based scalable wavelet video coding. A generalized 3-D object-based directional threading, which unifies the concepts of temporal motion threading and spatial directional threading, is seamlessly incorporated into 3-D shape-adaptive directional wavelet transform to exploit the spatio-temporal correlation inside the 3-D video object. To improve the computational efficiency of multi-resolution motion estimation (MRME) in shift-invariant wavelet domain, two fast MRME algorithms are proposed for wavelet-based scalable video coding. As demonstrated in the experiments, the proposed 3-D object-based wavelet video coding techniques consistently outperform MPEG-4 and other wavelet-based schemes for coding arbitrarily shaped video object, while providing full spatio-temporal-quality scalability with non-redundant 3-D subband decomposition.
Liu, Yu.
Adviser: King Ngi Ngan.
Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3693.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2008.
Includes bibliographical references (leaves 166-173).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts in English and Chinese.
School code: 1307.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Amiri, Delaram. "Bilateral and adaptive loop filter implementations in 3D-high efficiency video coding standard". Thesis, 2015. http://hdl.handle.net/1805/7983.

Testo completo

Abstract (sommario):

Indiana University-Purdue University Indianapolis (IUPUI)
In this thesis, we describe a different implementation for in loop filtering method for 3D-HEVC. First we propose the use of adaptive loop filtering (ALF) technique for 3D-HEVC standard in-loop filtering. This filter uses Wiener–based method to minimize the Mean Squared Error between filtered pixel and original pixels. The performance of adaptive loop filter in picture based level is evaluated. Results show up to of 0.2 dB PSNR improvement in Luminance component for the texture and 2.1 dB for the depth. In addition, we obtain up to 0.1 dB improvement in Chrominance component for the texture view after applying this filter in picture based filtering. Moreover, a design of an in-loop filtering with Fast Bilateral Filter for 3D-HEVC standard is proposed. Bilateral filter is a filter that smoothes an image while preserving strong edges and it can remove the artifacts in an image. Performance of the bilateral filter in picture based level for 3D-HEVC is evaluated. Test model HTM- 6.2 is used to demonstrate the results. Results show up to of 20 percent of reduction in processing time of 3D-HEVC with less than affecting PSNR of the encoded 3D video using Fast Bilateral Filter.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Augustine, Jacob. "Switching Theoretic Approach To Image Compression". Thesis, 1996. http://etd.iisc.ernet.in/handle/2005/1898.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Kesireddy, Akitha. "A new adaptive trilateral filter for in-loop filtering". Thesis, 2014. http://hdl.handle.net/1805/5927.

Testo completo

Abstract (sommario):

Indiana University-Purdue University Indianapolis (IUPUI)
HEVC has achieved significant coding efficiency improvement beyond existing video coding standard by employing many new coding tools. Deblocking Filter, Sample Adaptive Offset and Adaptive Loop Filter for in-loop filtering are currently introduced for the HEVC standardization. However these filters are implemented in spatial domain despite the fact of temporal correlation within video sequences. To reduce the artifacts and better align object boundaries in video , a new algorithm in in-loop filtering is proposed. The proposed algorithm is implemented in HM-11.0 software. This proposed algorithm allows an average bitrate reduction of about 0.7% and improves the PSNR of the decoded frame by 0.05%, 0.30% and 0.35% in luminance and chroma.

Gli stili APA, Harvard, Vancouver, ISO e altri

Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!