Wyniki wyszukiwania - BazTech

1

Analysis of the possibility of using the singular value decomposition in image compression

Łukasik Edyta, Łabuć Emilia

Applied Computer Science

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2022

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Vol. 18, no 4

53--67

EN

In today’s highly computerized world, data compression is a key issue to minimize the costs associated with data storage and transfer. In 2019, more than 70% of the data sent over the network were images. This paper analyses the feasibility of using the SVD algorithm in image compression and shows that it improves the efficiency of JPEG and JPEG2000 compression. Image matrices were decomposed using the SVD algorithm before compression. It has also been shown that as the image dimensions increase, the fraction of eigenvalues that must be used to reconstruct the image in good quality decreases. The study was carried out on a large and diverse set of images, more than 2500 images were examined. The results were analyzed based on criteria typical for the evaluation of numerical algorithms operating on matrices and image compression: compression ratio, size of compressed file, MSE, number of bad pixels, complexity, numerical stability, easiness of implementation.

2

Experimental analysis of picture quality after compression by different methods

Ilic S., Petrovic M., Jaksic B., Spalevic P., Lazic L., Milosevic M.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 11

190-194

EN

In this paper we present experimental results comparing the quality of still Black & White (B/W) images compressed using four methods: JPEG, JPEG2000, EZW and SPIHT. The compression was performed on three pictures with differing levels of detail and density (bit-rates - bpp) using VCDemo software. The quality of the compressed pictures is determined by values of MSE, SNR and PSNR. The values are presented in appropriate tables and diagrams. By comparing the values obtained, we have found the methods that give best results depending on the picture bitrate and level of detail.

PL

W artykule opisano rezultaty eksperymentalnego badania kompresji obrazu czarno/białego przy wykorzystaniu czterech metod: JPEG, JPEG2000, EZW i SPIHT. Kompresję wykonywano na trzech obrazach o różnym poziomie detali i różnej gęstości.

3

Ordering of diagnostic information in encoded medical images : accuracy progression

Przelaskowski A., Jóźwiak R., Krzyżewski T., Wróblewska A.

Opto-Electronics Review

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2008

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Vol. 16, No. 1

49-59

EN

A concept of diagnostic accuracy progression for embedded coding of medical images was presented. Implementation of JPEG2000 encoder with a modified PCRD optimization algorithm was realized and initially verified as a tool for accurate medical image streaming. Mean square error as a distortion measure was replaced by other numerical measures to revise quality progression according to diagnostic importance of successively encoded image information. A faster increment of image diagnostic importance during reconstruction of initial packets of code stream was reached. Modified Jasper code was initially tested on a set of mammograms containing clusters of microcalcifications and malignant masses, and other radiograms. Teleradiologic applications were considered as the first area of interests.

4

Unified JPEG and JPEG-2000 color descriptor for content-based image retrieval

Forczmański P.

Metody Informatyki Stosowanej

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2008

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nr 4 (Tom 17)

53--62

EN

The problem investigated in this paper refers to image retrieval based on its compressed form, hence giving much advantages in comparison to traditional methods involving image decompression. The main goal of this paper is to discuss a unified visual descriptor for images stored in the two most popular image formats – JPEG/JFIF and JPEG-2000 in the aspect of content-based image retrieval (CBIR). Since the problem of CBIR takes a special interest nowadays, it is clear that new approaches should be discussed. To achieve such goal a unified descriptor is proposed based on low-level visual features. The algorithm operates in both DCT and DWT compressed domains to build a uniform, format-independent index. It is represented by a three-dimensional color histogram computed in CIE L*a*b* color space. Sample software implementation employs a compact descriptor calculated for each image and stored in a database-like structure. For a particular query image, a comparison in the feature-space is performed, giving information about images' similarity. Finally, images with the highest scores are retrieved and presented to the user. The paper provides an analysis of this approach as well as the initial results of application in the field of CBIR.

5

Interactive image browsing with JPEG2000 Internet Protocol

Saganowski Ł.

Przegląd Elektrotechniczny

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2006

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R. 82, nr 1

58-62

EN

JPEG2000 Internet Protocol (JPIP) and JPEG2000 give powerful and flexible client/server architecture that takes advantage of efficient compression and existing internet protocols. We can store only one compressed file at the server side and transmit image to the client. At the client side user can select quality, Region of Interest (ROI) of the image. These operations do not require to transmit or decode entire codestream. Only specific data connected with ROI or quality level are transmitted to the client. This minimizes server computational burden, storage and bandwidth.

PL

JPEG2000 Internet Protocol (JPIP) razem z kompresją JPEG2000 tworzą wydajny i elastyczny system typu klient/serwer czerpiący korzyści z wydajnego systemu kompresji oraz istniejących protokołów internetowych. Po stronie serwera możemy zapisać tylko jeden skompresowany obraz. Po stronie klienta wybieramy jakość przesyłanego obrazu lub obszar zainteresowania w obrazie - Region of Interest ROI.

6

Sprzętowa akceleracja kodeka arytmetycznego dla standardu JPEG2000

Naglik M., Szafraniec R., Russek P., Wiatr K.

Pomiary Automatyka Kontrola

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2006

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R. 52, nr 7 bis

89--91

PL

Autorzy prezentują rozwiązanie sprzętowe kodera i dekodera arytmetycznego zaimplementowanego w układzie FPGA Virtex. Rozwiązanie sprzętowe kodera pozwala na bardziej efektywną niż to ma miejsce w procesorze ogólnego stosowania realizację kodowania entropowego. Zrealizowany kodek jest częścią składową opracowywanego kodera/dekodera JPEG2000. Zastosowanie technologii reprogramowalnej pozwoli na lepsze wykorzystanie zasobów sprzętowych systemu.

EN

Authors present hardware solution of arithmetic encoder and decoder implemented in Xilinx Virtex FPGA. Hardware approach allows for more effective performance of coding if compared to the software implementations. Presented codec is a part of being designed by authors hardware processor for JPEG2000 compression. Utilization of FPGA technology allows for better digital resources usage.

7

Gaze-J2K: gaze-influenced image coding using eye trackers and JPEG 2000

Nguyen A., Chandran V., Sridharan S.

Journal of Telecommunications and Information Technology

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2006

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nr 1

3-10

EN

The use of visual content in applications of the digital computer has increased dramatically with the advent of the Internet and world wide web. Image coding standards such as JPEG 2000 have been developed to provide scalable and progressive compression of imagery. Advances in image and video analysis are also making human-computer interaction multi-modal rather than through the use of a keyboard or mouse. An eye tracker is an example input device that can be used by an application that displays visual content to adapt to the viewer. Many features are required of the format to facilitate this adaptation, and some are already part of image coding standards such as JPEG 2000. This paper presents a system incorporating the use of eye tracking and JPEG 2000, called Gaze-J2K, to allow a customised encoding of an image by using a user's gaze pattern. The gaze pattern is used to automatically determine and assign importance to fixated regions in an image, and subsequently constrain the encoding of the image to these regions.

8

JPIP - JPEG2000 Internet Protocol

Saganowski Ł.

Image Processing & Communications

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2005

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Vol. 10, no 1

53-61

EN

JPEG2000 is an efficient image compression standard based on DWT (Digital Wavelet Transform) which provides interactive access to large images. JPEG2000 Internet Protocol (JPIP) and JPEG2000 gives powerful and flexible client/server architecture that takes advantage of efficient compression and existing internet protocols. We can store only one compressed file at the server side and transmit image to the client- At the client side user can select quality , Region of Interest (ROI) of the image. This operations doesn't require to transmit or decode entire code-stream. Only specific data connected with ROI or quality level are transmitted to the client.

9

The JPEG2000 standard for medical image applications

Przelaskowski A.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2004

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Vol. 8, No 2

147-158

EN

A new standard of still image compression is characterised in the context of medical applications. Wide spectrum of JPEG2000 features is analysed with respect to its application potential to improve the performance of modern medical services (i.e. telemedicine, PACS, radiology information systems, wireless personal/home health care systems). Image data security techniques, error resilience technologies, client-side interactive Region of Interest (ROI) transmission and decoding (e.g. for teleconsultation with very large radiography exams), and storage of multiple image data sets are considered in detail. Selected tests of coders realized according to parts I and II of JPEG2000 for different modality test images are presented to evaluate the compression efficacy of this standard. Exemplary results of encoding process optimisation by wavelet transform and subband decomposition selection and screen-shots of software interfaces designed for these tests are also presented.

10

Przegląd metod bezstratnej kompresji obrazów medycznych

Starosolski R.

Studia Informatica

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2004

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Vol. 25, nr 2

49-66

PL

Niniejszy artykuł zawiera zwarty przegląd algorytmów z zakresu bezstratnej kompresji statycznych obrazów medycznych. Uwzględniono zarówno agorytmy, które uznawane są za standardy w medycznych systemach składowania i transmisji obrazów, jak również inne algorytmy praktycznie stosowane do kompresji takich danych. Przedstawiono również ogólną charakterystykę klas obrazów medycznych, wyróżniając te cechy omawianych klas obrazów, które są istotne przy konstrukcji lub wyborze algorytmu kompresji obrazów należących do tych klas.

EN

In this paper we present a brief overview of lossless medical image compression algorithms. We overview both algorithms that arę considered to be stan-dards in medical image transmitting and archiving systems and other algorithms used for compressing medical images. We also generally describe main classes of medical images, distinguishing features that arę crucial in development and selection of algo-rithms appropriate for compressing images belonging to those classes.