Academic literature on the topic 'Discrete wavelet transform (DWT)'

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Journal articles on the topic "Discrete wavelet transform (DWT)"

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Guido, Rodrigo Capobianco, Fernando Pedroso, André Furlan, Rodrigo Colnago Contreras, Luiz Gustavo Caobianco, and Jogi Suda Neto. "CWT × DWT × DTWT × SDTWT: Clarifying terminologies and roles of different types of wavelet transforms." International Journal of Wavelets, Multiresolution and Information Processing 18, no. 06 (August 28, 2020): 2030001. http://dx.doi.org/10.1142/s0219691320300017.

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Wavelets have been placed at the forefront of scientific researches involving signal processing, applied mathematics, pattern recognition and related fields. Nevertheless, as we have observed, students and young researchers still make mistakes when referring to one of the most relevant tools for time–frequency signal analysis. Thus, this correspondence clarifies the terminologies and specific roles of four types of wavelet transforms: the continuous wavelet transform (CWT), the discrete wavelet transform (DWT), the discrete-time wavelet transform (DTWT) and the stationary discrete-time wavelet transform (SDTWT). We believe that, after reading this correspondence, readers will be able to correctly refer to, and identify, the most appropriate type of wavelet transform for a certain application, selecting relevant and accurate material for subsequent investigation.
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Tang, Ling, Ming Ju Chen, and Hong Song. "Hybrid Color Image Compression Using Discrete Cosine Transform and Discrete Wavelet Transform." Applied Mechanics and Materials 198-199 (September 2012): 244–48. http://dx.doi.org/10.4028/www.scientific.net/amm.198-199.244.

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In this research we undertake a study of image compression based on the discrete cosine transform(DCT) and discrete wavelet transform(DWT). Then a hybrid color image compression algorithm based on DCT and DWT is proposed. This algorithm is implemented through transform the color image using DWT in the YCbCr space first, and then DCT in the low frequency, adopt huffman coding, RLE and arithmetic coding in the encoded mode. In experiments, the results outperform the only DCT and the only DWT typically higher in peak signal-to-noise ratio and have better visual quality.
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Balsa, Jose. "Comparison of Image Compressions: Analog Transformations." Proceedings 54, no. 1 (August 21, 2020): 37. http://dx.doi.org/10.3390/proceedings2020054037.

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A comparison between the four most used transforms, the discrete Fourier transform (DFT), discrete cosine transform (DCT), the Walsh–Hadamard transform (WHT) and the Haar-wavelet transform (DWT), for the transmission of analog images, varying their compression and comparing their quality, is presented. Additionally, performance tests are done for different levels of white Gaussian additive noise.
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Dabou, Raoult Teukam, Innocent Kamwa, Jacques Tagoudjeu, and Francis Chuma Mugombozi. "Sparse Signal Reconstruction on Fixed and Adaptive Supervised Dictionary Learning for Transient Stability Assessment." Energies 14, no. 23 (November 30, 2021): 7995. http://dx.doi.org/10.3390/en14237995.

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Fixed and adaptive supervised dictionary learning (SDL) is proposed in this paper for wide-area stability assessment. Single and hybrid fixed structures are developed based on impulse dictionary (ID), discrete Haar transform (DHT), discrete cosine transform (DCT), discrete sine transform (DST), and discrete wavelet transform (DWT) for sparse features extraction and online transient stability prediction. The fixed structures performance is compared with that obtained from transient K-singular value decomposition (TK-SVD) implemented while adding a stability status term to the optimization problem. Stable and unstable dictionary learning are designed based on datasets recorded by simulating thousands of contingencies with varying faults, load, and generator switching on the IEEE 68-bus test system. This separate supervised learning of stable and unstable scenarios allows determining root mean square error (RMSE), useful for online stability status assessment of new scenarios. With respect to the RMSE performance metric in signal reconstruction-based stability prediction, the present analysis demonstrates that [DWT], [DHT|DWT] and [DST|DHT|DCT] are better stability descriptors compared to K-SVD, [DHT], [DCT], [DCT|DWT], [DHT|DCT], [ID|DCT|DST], and [DWT|DHT|DCT] on test datasets. However, the K-SVD approach is faster to execute in both off-line training and real-time playback while yielding satisfactory accuracy in transient stability prediction (i.e., 7.5-cycles decision window after fault-clearing).
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Setyono, Andik, and De Rosal Ignatius Moses Setiadi. "Image watermarking using discrete wavelet-tchebichef transform." Indonesian Journal of Electrical Engineering and Computer Science 16, no. 3 (December 1, 2019): 1416. http://dx.doi.org/10.11591/ijeecs.v16.i3.pp1416-1423.

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<span>Image watermarking is one of the most popular techniques for authenticating copyright on the digital image. Many research on image watermarking has proved that the joint of Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) combinations can improve both imperceptibility and robustness when compared to DCT or DWT only. Discrete Tchebichef Transform (DTT) denotes an alternative transformation that has a similarity property with DCT. DTT has an advantage in reducing memory requirements during computing, so the calculation speed is much faster than DCT. This study tested the performance of DTT and DCT on non-blind image watermarking method, where DTT and DCT are performed after DWT. Based on the experimental results, this research proved that the DTT was combined successfully with DWT and very potential for further investigation because it has a computing performance much better than DCT. While the image watermarking quality, both the imperceptibility and robustness aspects were completely identical with the combination of DCT and DWT transformation.</span>
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Maulida, Kurnia. "Studi Komparasi Video Watermarking dengan Algoritma Discrete Wavelet Transform dan Discrete Cosine Transform." MATHunesa: Jurnal Ilmiah Matematika 8, no. 3 (November 21, 2020): 254–60. http://dx.doi.org/10.26740/mathunesa.v8n3.p254-260.

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Perkembangan teknologi di era digital berkembang dengan sangat cepat setiap harinya. Dengan perkembangan teknologi digital saat ini, media sosial dapat memudahkan kita untuk mengakses serta mendistribusikan teks, gambar, video, dan lainnya. Risiko terjadinya kejahatan di video lebih tinggi dibandingkan dengan teks dan gambar. Digital watermarking dapat digunakan untuk melindungi informasi digital dari manipulasi dan distribusi illegal. Penyisipan watermark umumnya dilakukan dalam domain spasial atau domain frekuensi. Metode yang digunakan adalah Discrete Wavelet Transform (DWT) dan Discrete Cosine Transform (DCT). DWT digunakan untuk mendapatkan komponen multi-resolusi yaitu horisontal, vertikal dan diagonal dari suatu gambar. Sedangkan, DCT memisahkan setiap blok gambar menjadi pita frekuensi rendah, sedang dan tinggi. PSNR adalah rasio antara kekuatan maksimum yang mungkin dari sinyal dan kekuatan noise yang merusak. Berdasarkan penelitian yang dilakukan penulis semakin besar koefisien DCT/DWT maka semakin bagus kualitas gambar hasil ekstrak. Hasil uji coba menunjukkan nilai PSNR video watermark menggunakan DWT lebih besar daripada nilai PSNR video watermark menggunakan DCT. Namun, selisih nilai PSNR antara DWT dan DCT sangat kecil. Nilai PSNR video watermark lebih kecil dari 30 mengindikasikan kedua video memiliki kemiripan yang rendah. Semakin besar nilai PSNR video semakin bagus kualitas video tersebut.
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BELKASIM, SAEID, XIANYU HONG, and O. BASIR. "CONTENT BASED IMAGE RETRIEVAL USING DISCRETE WAVELET TRANSFORM." International Journal of Pattern Recognition and Artificial Intelligence 18, no. 01 (February 2004): 19–32. http://dx.doi.org/10.1142/s0218001404003046.

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Image retrieval plays an important role in a broad spectrum of applications. Contentbased retrieval (CBR) is one of the popular choices in many biomedical and industrial applications. Discrete image transforms have been widely studied and suggested for many image retrieval applications. The Discrete Wavelet Transform (DWT) is one of the most popular transforms recently applied to many image processing applications. The Daubechies wavelet can be used to form the basis for extracting features in retrieving images based on the description of a particular object within the scene. This wavelet is widely used for image compression. In this paper we highlight the common features between compression and retrieval. Several examples are used to test the DWT retrieval system. A comparison between DWT and Discrete Cosine Transform (DCT) is also made. The retrieval system using DWT requires preprocessing and normalization of images, which might slow down the retrieval process. The accuracy of the retrieval using DWT has been significantly improved by incorporating efficient K-Neighbor Nearest Distance (KNND) measure in our system.
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Abdullah, Shahrum, S. N. Sahadan, Mohd Zaki Nuawi, and Zulkifli Mohd Nopiah. "Fatigue Data Analysis Using Continuous Wavelet Transform and Discrete Wavelet Transform." Key Engineering Materials 462-463 (January 2011): 461–66. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.461.

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The wavelet transform is well known for its ability in vibration analysis in fault detection. This paper presents the ability of wavelet transform in fatigue data analysis starts from high amplitude events detection and it is then followed by fatigue data extraction based on wavelet coefficients. Since the wavelet transform has two main categories, i.e. the continuous wavelet transforms (CWT) and the discrete wavelet transform (DWT), the comparison study were carried out in order to investigate performance of both wavelet for fatigue data analysis. CWT represents by the Morlet wavelet while DWT with the form of the 4th Order Daubechies wavelet (Db4) was also used for the analysis. An analysis begins with coefficients plot using the time-scale representation that associated to energy coefficients plot for the input value in fatigue data extraction. Ten extraction levels were used and all levels gave the damage difference, (%∆D) less than 10% with respect to original signal. From the study, both wavelet transforms gave almost similar ability in editing fatigue data but the Morlet wavelet provided faster analysis time compared to the Db4 wavelet. In comparison to have the value of different at 5%, the Morlet wavelet achieved at L= 5 while the Db4 wavelet at L=7. Even though it gave slower analysis time, both wavelets can be used in fatigue data editing but at different time consuming.
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Toda, Hiroshi, Zhong Zhang, and Takashi Imamura. "Practical design of perfect-translation-invariant real-valued discrete wavelet transform." International Journal of Wavelets, Multiresolution and Information Processing 12, no. 04 (July 2014): 1460005. http://dx.doi.org/10.1142/s0219691314600054.

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The real-valued tight wavelet frame having perfect translation invariance (PTI) has already proposed. However, due to the irrational-number distances between wavelets, its calculation amount is very large. In this paper, based on the real-valued tight wavelet frame, a practical design of a real-valued discrete wavelet transform (DWT) having PTI is proposed. In this transform, all the distances between wavelets are multiples of 1/4, and its transform and inverse transform are calculated fast by decomposition and reconstruction algorithms at the sacrifice of a tight wavelet frame. However, the real-valued DWT achieves an approximate tight wavelet frame.
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Nigam, Vaibhav, Smriti Bhatnagar, and Sajal Luthra. "Image Denoising Using Wavelet Transform and Wavelet Transform with Enhanced Diversity." Advanced Materials Research 403-408 (November 2011): 866–70. http://dx.doi.org/10.4028/www.scientific.net/amr.403-408.866.

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This paper is a comparative study of image denoising using previously known wavelet transform and new type of wavelet transform, namely, Diversity enhanced discrete wavelet transform. The Discrete Wavelet Transform (DWT) has two parameters: the mother wavelet and the number of iterations. For every noisy image, there is a best pair of parameters for which we get maximum output Peak Signal to Noise Ratio, PSNR. As the denoising algorithms are sensitive to the parameters of the wavelet transform used, in this paper comparison of DEDWT to DWT has been presented. The diversity is enhanced by computing wavelet transforms with different parameters. After the filtering of each detail coefficient, the corresponding wavelet transforms are inverted and the estimated image, having a higher PSNR, is extracted. To benchmark against the best possible denoising method three thresholding techniques have been compared. In this paper we have presented a more practical, implementation oriented work.
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Dissertations / Theses on the topic "Discrete wavelet transform (DWT)"

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Johansson, Gustaf. "Scalable video coding using the Discrete Wavelet Transform : Skalbar videokodning med användning av den diskreta wavelettransformen." Thesis, Linköping University, Information Coding, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-54637.

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A method for constructing a highly scalable bit stream for video coding is presented in detail and implemented in a demo application with a GUI in the Windows Vista operating system.

The video codec uses the Discrete Wavelet Transform in both spatial and temporal directions together with a zerotree quantizer to achieve a highly scalable bit stream in the senses of quality, spatial resolution and frame rate.


I detta arbete presenteras en metod för att skapa en mycket skalbar videoström. Metoden implementeras sedan i sin helhet i programspråken C och C++ med ett grafiskt användargränssnitt på operativsystemet Windows Vista.

I metoden används den diskreta wavelettransformen i såväl de spatiella dimensionerna som tidsdimensionen tillsammans med en nollträdskvantiserare för att åstakomma en skalbar videoström i avseendena bildkvalitet, skärmupplösning och antal bildrutor per sekund.

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Boland, Simon Daniel. "High quality audio coding using the wavelet transform." Thesis, Queensland University of Technology, 1998.

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Abdallah, Abdallah Sabry. "Investigation of New Techniques for Face detection." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/33191.

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The task of detecting human faces within either a still image or a video frame is one of the most popular object detection problems. For the last twenty years researchers have shown great interest in this problem because it is an essential pre-processing stage for computing systems that process human faces as input data. Example applications include face recognition systems, vision systems for autonomous robots, human computer interaction systems (HCI), surveillance systems, biometric based authentication systems, video transmission and video compression systems, and content based image retrieval systems. In this thesis, non-traditional methods are investigated for detecting human faces within color images or video frames. The attempted methods are chosen such that the required computing power and memory consumption are adequate for real-time hardware implementation. First, a standard color image database is introduced in order to accomplish fair evaluation and benchmarking of face detection and skin segmentation approaches. Next, a new pre-processing scheme based on skin segmentation is presented to prepare the input image for feature extraction. The presented pre-processing scheme requires relatively low computing power and memory needs. Then, several feature extraction techniques are evaluated. This thesis introduces feature extraction based on Two Dimensional Discrete Cosine Transform (2D-DCT), Two Dimensional Discrete Wavelet Transform (2D-DWT), geometrical moment invariants, and edge detection. It also attempts to construct a hybrid feature vector by the fusion between 2D-DCT coefficients and edge information, as well as the fusion between 2D-DWT coefficients and geometrical moments. A self organizing map (SOM) based classifier is used within all the experiments to distinguish between facial and non-facial samples. Two strategies are tried to make the final decision from the output of a single SOM or multiple SOM. Finally, an FPGA based framework that implements the presented techniques, is presented as well as a partial implementation. Every presented technique has been evaluated consistently using the same dataset. The experiments show very promising results. The highest detection rate of 89.2% was obtained when using a fusion between DCT coefficients and edge information to construct the feature vector. A second highest rate of 88.7% was achieved by using a fusion between DWT coefficients and geometrical moments. Finally, a third highest rate of 85.2% was obtained by calculating the moments of edges.
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Jassim, Taha D. "Combined robust and fragile watermarking algorithms for still images. Design and evaluation of combined blind discrete wavelet transform-based robust watermarking algorithms for copyright protection using mobile phone numbers and fragile watermarking algorithms for content authentication of digital still images using hash functions." Thesis, University of Bradford, 2014. http://hdl.handle.net/10454/6460.

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This thesis deals with copyright protection and content authentication for still images. New blind transform domain block based algorithms using one-level and two-level Discrete Wavelet Transform (DWT) were developed for copyright protection. The mobile number with international code is used as the watermarking data. The robust algorithms used the Low-Low frequency coefficients of the DWT to embed the watermarking information. The watermarking information is embedded in the green channel of the RGB colour image and Y channel of the YCbCr images. The watermarking information is scrambled by using a secret key to increase the security of the algorithms. Due to the small size of the watermarking information comparing to the host image size, the embedding process is repeated several times which resulted in increasing the robustness of the algorithms. Shuffling process is implemented during the multi embedding process in order to avoid spatial correlation between the host image and the watermarking information. The effects of using one-level and two-level of DWT on the robustness and image quality have been studied. The Peak Signal to Noise Ratio (PSNR), the Structural Similarity Index Measure (SSIM) and Normalized Correlation Coefficient (NCC) are used to evaluate the fidelity of the images. Several grey and still colour images are used to test the new robust algorithms. The new algorithms offered better results in the robustness against different attacks such as JPEG compression, scaling, salt and pepper noise, Gaussian noise, filters and other image processing compared to DCT based algorithms. The authenticity of the images were assessed by using a fragile watermarking algorithm by using hash function (MD5) as watermarking information embedded in the spatial domain. The new algorithm showed high sensitivity against any tampering on the watermarked images. The combined fragile and robust watermarking caused minimal distortion to the images. The combined scheme achieved both the copyright protection and content authentication.
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Jassim, Taha Dawood. "Combined robust and fragile watermarking algorithms for still images : design and evaluation of combined blind discrete wavelet transform-based robust watermarking algorithms for copyright protection using mobile phone numbers and fragile watermarking algorithms for content authentication of digital still images using hash functions." Thesis, University of Bradford, 2014. http://hdl.handle.net/10454/6460.

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This thesis deals with copyright protection and content authentication for still images. New blind transform domain block based algorithms using one-level and two-level Discrete Wavelet Transform (DWT) were developed for copyright protection. The mobile number with international code is used as the watermarking data. The robust algorithms used the Low-Low frequency coefficients of the DWT to embed the watermarking information. The watermarking information is embedded in the green channel of the RGB colour image and Y channel of the YCbCr images. The watermarking information is scrambled by using a secret key to increase the security of the algorithms. Due to the small size of the watermarking information comparing to the host image size, the embedding process is repeated several times which resulted in increasing the robustness of the algorithms. Shuffling process is implemented during the multi embedding process in order to avoid spatial correlation between the host image and the watermarking information. The effects of using one-level and two-level of DWT on the robustness and image quality have been studied. The Peak Signal to Noise Ratio (PSNR), the Structural Similarity Index Measure (SSIM) and Normalized Correlation Coefficient (NCC) are used to evaluate the fidelity of the images. Several grey and still colour images are used to test the new robust algorithms. The new algorithms offered better results in the robustness against different attacks such as JPEG compression, scaling, salt and pepper noise, Gaussian noise, filters and other image processing compared to DCT based algorithms. The authenticity of the images were assessed by using a fragile watermarking algorithm by using hash function (MD5) as watermarking information embedded in the spatial domain. The new algorithm showed high sensitivity against any tampering on the watermarked images. The combined fragile and robust watermarking caused minimal distortion to the images. The combined scheme achieved both the copyright protection and content authentication.
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Donovan, Rory Larson. "Hand (Motor) Movement Imagery Classification of EEG Using Takagi-Sugeno-Kang Fuzzy-Inference Neural Network." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1754.

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Approximately 20 million people in the United States suffer from irreversible nerve damage and would benefit from a neuroprosthetic device modulated by a Brain-Computer Interface (BCI). These devices restore independence by replacing peripheral nervous system functions such as peripheral control. Although there are currently devices under investigation, contemporary methods fail to offer adaptability and proper signal recognition for output devices. Human anatomical differences prevent the use of a fixed model system from providing consistent classification performance among various subjects. Furthermore, notoriously noisy signals such as Electroencephalography (EEG) require complex measures for signal detection. Therefore, there remains a tremendous need to explore and improve new algorithms. This report investigates a signal-processing model that is better suited for BCI applications because it incorporates machine learning and fuzzy logic. Whereas traditional machine learning techniques utilize precise functions to map the input into the feature space, fuzzy-neuro system apply imprecise membership functions to account for uncertainty and can be updated via supervised learning. Thus, this method is better equipped to tolerate uncertainty and improve performance over time. Moreover, a variation of this algorithm used in this study has a higher convergence speed. The proposed two-stage signal-processing model consists of feature extraction and feature translation, with an emphasis on the latter. The feature extraction phase includes Blind Source Separation (BSS) and the Discrete Wavelet Transform (DWT), and the feature translation stage includes the Takagi-Sugeno-Kang Fuzzy-Neural Network (TSKFNN). Performance of the proposed model corresponds to an average classification accuracy of 79.4 % for 40 subjects, which is higher than the standard literature values, 75%, making this a superior model.
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Koglin, Ryan W. "Efficient Image Processing Techniques for Enhanced Visualization of Brain Tumor Margins." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1415835138.

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Kang, Pengju. "On-line condition assessment of power transformer on-load tap-changers : transient vibration analysis using wavelet transform and self organising map." Thesis, Queensland University of Technology, 2000.

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Chintala, Bala Venkata Sai Sundeep. "Objective Perceptual Quality Assessment of JPEG2000 Image Coding Format Over Wireless Channel." Thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-17785.

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A dominant source of Internet traffic, today, is constituted of compressed images. In modern multimedia communications, image compression plays an important role. Some of the image compression standards set by the Joint Photographic Expert Group (JPEG) include JPEG and JPEG2000. The expert group came up with the JPEG image compression standard so that still pictures could be compressed to be sent over an e-mail, be displayed on a webpage, and make high-resolution digital photography possible. This standard was originally based on a mathematical method, used to convert a sequence of data to the frequency domain, called the Discrete Cosine Transform (DCT). In the year 2000, however, a new standard was proposed by the expert group which came to be known as JPEG2000. The difference between the two is that the latter is capable of providing better compression efficiency. There is also a downside to this new format introduced. The computation required for achieving the same sort of compression efficiency as one would get with the original JPEG format is higher. JPEG is a lossy compression standard which can throw away some less important information without causing any noticeable perception differences. Whereas, in lossless compression, the primary purpose is to reduce the number of bits required to represent the original image samples without any loss of information. The areas of application of the JPEG image compression standard include the Internet, digital cameras, printing, and scanning peripherals. In this thesis work, a simulator kind of functionality setup is needed for conducting the objective quality assessment. An image is given as an input to our wireless communication system and its data size is varied (e.g. 5%, 10%, 15%, etc) and a Signal-to-Noise Ratio (SNR) value is given as input, for JPEG2000 compression. Then, this compressed image is passed through a JPEG encoder and then transmitted over a Rayleigh fading channel. The corresponding image obtained after having applied these constraints on the original image is then decoded at the receiver and inverse discrete wavelet transform (IDWT) is applied to inverse the JPEG 2000 compression. Quantization is done for the coefficients which are scalar-quantized to reduce the number of bits to represent them, without the loss of quality of the image. Then the final image is displayed on the screen. The original input image is co-passed with the images of varying data size for an SNR value at the receiver after decoding. In particular, objective perceptual quality assessment through Structural Similarity (SSIM) index using MATLAB is provided.
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Čáp, Martin. "Sledování trendů elektrické aktivity srdce časově-frekvenčním rozkladem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218005.

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Work is aimed at the time-frequency decomposition of a signal application for monitoring the EKG trend progression. Goal is to create algorithm which would watch changes in the ST segment in EKG recording and its realization in the Matlab program. Analyzed is substance of the origin of EKG and its measuring. For trend calculations after reading the signal is necessary to preprocess the signal, it consists of filtration and detection of necessary points of EKG signal. For taking apart, also filtration and measuring the signal is used wavelet transformation. Source of the data is biomedicine database Physionet. As an outcome of the algorithm are drawn ST segment trends for three recordings from three different patients and its comparison with reference method of ST qualification. For qualification of the heart stability, as a system, where designed methods watching differences in position of the maximal value in two-zone spectrum and the Poincare mapping method. Realized method is attached to this thesis.
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Books on the topic "Discrete wavelet transform (DWT)"

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Shukla, K. K., and Arvind K. Tiwari. Efficient Algorithms for Discrete Wavelet Transform. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-4941-5.

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Discrete wavelet transform: A signal processing approach. Chichester, UK: John Wiley & Sons, 2015.

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1973-, La Cour-Harbo A., ed. Ripples in mathematics: The discrete wavelet transform. Berlin: Springer, 2001.

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Pham, Tuan Van. Wavelet analysis for robust speech processing and applications: Applications of discrete wavelet transform and wavelet denoising to speech enhancement and robust speech recognition. Saarbrücken: VDM, Verlag Dr. Müller, 2008.

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Shukla, K. K. Efficient Algorithms for Discrete Wavelet Transform: With Applications to Denoising and Fuzzy Inference Systems. London: Springer London, 2013.

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Jer-Nan, Juang, Institute for Computer Applications in Science and Engineering., and United States. National Aeronautics and Space Administration., eds. A novel approach for adaptive signal processing. Hampton, VA: Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1998.

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Shukla, K. K., and Arvind K. Tiwari. Efficient Algorithms for Discrete Wavelet Transform. Springer, 2013.

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Ripples in Mathematics: The Discrete Wavelet Transform. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001.

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Sundararajan, D. Discrete Wavelet Transform: A Signal Processing Approach. Wiley & Sons, Limited, John, 2015.

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Sundararajan, D. Discrete Wavelet Transform: A Signal Processing Approach. Wiley & Sons, Incorporated, John, 2015.

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Book chapters on the topic "Discrete wavelet transform (DWT)"

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Alessio, Silvia Maria. "Discrete Wavelet Transform (DWT)." In Signals and Communication Technology, 645–714. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-25468-5_14.

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Shukla, K. K., and Arvind K. Tiwari. "Filter Banks and DWT." In Efficient Algorithms for Discrete Wavelet Transform, 21–36. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-4941-5_2.

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Shukla, K. K., and Arvind K. Tiwari. "DWT-Based Power Quality Classification." In Efficient Algorithms for Discrete Wavelet Transform, 61–81. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-4941-5_5.

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Shukla, K. K., and Arvind K. Tiwari. "PVM Implementation of DWT-Based Image Denoising." In Efficient Algorithms for Discrete Wavelet Transform, 51–59. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-4941-5_4.

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Thanki, Rohit M., Vedvyas J. Dwivedi, and Komal R. Borisagar. "Multibiometric Watermarking Technique Using Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT)." In Multibiometric Watermarking with Compressive Sensing Theory, 91–113. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73183-4_5.

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Thanki, Rohit M., Vedvyas J. Dwivedi, and Komal R. Borisagar. "Multibiometric Watermarking Technique Using Discrete Wavelet Transform (DWT)." In Multibiometric Watermarking with Compressive Sensing Theory, 65–89. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73183-4_4.

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Kumar, Ashwani, S. P. Ghrera, and Vipin Tyagi. "A Comparison of Buyer-Seller Watermarking Protocol (BSWP) Based on Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT)." In Advances in Intelligent Systems and Computing, 401–8. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-13728-5_45.

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Thanki, Rohit M., Vedvyas J. Dwivedi, and Komal R. Borisagar. "Multibiometric Watermarking Technique Using Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD)." In Multibiometric Watermarking with Compressive Sensing Theory, 115–36. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73183-4_6.

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Alharbi, Ayidh, and Tahar M. Kechadi. "A Novel Steganography Algorithm Based on Alpha Blending Technique Using Discrete Wavelet Transform (ABT-DWT)." In Information Systems and Technologies to Support Learning, 342–51. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-03577-8_38.

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Rhif, Manel, Ali Ben Abbes, Imed Riadh Farah, and Beatriz Martínez. "Trend Analysis Using Discrete Wavelet Transform (DWT) for Non-stationary NDVI Time Series in Tunisia." In Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions (2nd Edition), 1869–73. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-51210-1_294.

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Conference papers on the topic "Discrete wavelet transform (DWT)"

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Aggarwal, Ankita, and Gurmeet Kaur. "Development of an Efficient Indoor Optical System using Different Wavelet Transforms." In International Conference on Women Researchers in Electronics and Computing. AIJR Publisher, 2021. http://dx.doi.org/10.21467/proceedings.114.35.

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For an effective communication system whether indoor or outdoor, the most important concern is minimum noise. In this paper, an efficient noise reduction technique is presented using various wavelet transform techniques for indoor optical wireless communication system (IOWC). In IOWC system, Fluorescent Light Interference (FLI) is main source of noise. Here, in this paper three methods are used to reduce the effect of noise from a digital signal. These are Discrete Wavelet Transform (DWT), Stationary Wavelet transform (SWT) and Discrete Wavelet transform-Stationary Wavelet Transform (DWT-SWT). Through sub band coding in DWT the signal is decomposed into lower sub bands of high and low frequency respectively of unequal size; while in SWT the decomposed signal have sub bands of equal size. In DWT-SWT the high frequency components of both DWT and SWT are added. Using Pulse Position Modulation, the comparison between these three techniques is described here to enhance the overall performance of the IOWC system.
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Nicholl, Paul, Afandi Ahmad, and Abbes Amira. "Optimal discrete wavelet transform (DWT) features for face recognition." In APCCAS 2010-2010 IEEE Asia Pacific Conference on Circuits and Systems. IEEE, 2010. http://dx.doi.org/10.1109/apccas.2010.5774907.

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Trambadia, Smit, and Hemant Mayatra. "Image inpainting based on Discrete Wavelet Transform (DWT) technique." In 2016 Online International Conference on Green Engineering and Technologies (IC-GET). IEEE, 2016. http://dx.doi.org/10.1109/get.2016.7916794.

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Wei, Jun, Pongskorn Saipetch, Ramesh K. Panwar, Doris T. Chin, and Bruce K. T. Ho. "Volumetric image compression by 3D discrete wavelet transform (DWT)." In Medical Imaging 1995, edited by Yongmin Kim. SPIE, 1995. http://dx.doi.org/10.1117/12.207612.

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Shin, Jin, and Hyun Kim. "DWT+DWT: Deep Learning Domain Generalization Techniques Using Discrete Wavelet Transform with Deep Whitening Transform." In 2023 International Conference on Electronics, Information, and Communication (ICEIC). IEEE, 2023. http://dx.doi.org/10.1109/iceic57457.2023.10049902.

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Panta Pazos, Rube´n. "Treatment of Noise in Experimental Transport Measurements Plots With Discrete Wavelet Transforms." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75731.

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In this work it is applied the wavelet transform method [2] in order to reduce diverse type of noises of experimental measurement plots in transport theory. First, suppose that a problem is governed by the transport equation for neutral particles, and an unknown perturbation occurs. In this case, the perturbation can be associated to the source, or even to the flux inside the domain X. How is the behavior of the perturbed flux in relation to the flux without the perturbation? For that, we employ the wavelet transform method in order to compress the angular flux considered as a 1D, or n-th dimensional signal ψ. The compression of this signal can be performed up to some a convenient order (that depends of the length of the signal). Now, the transport signal is decomposed as [9, 11]: ψ=〈am|dm|dm−1|dm−2|⋯|d2|d1〉 where ak represents the sub signal of k-th level generated by the low-pass filter associated to the discrete wavelet transform (DWT) chosen, and dk the sub signal of k-th level generated by the high-pass filter associated to the same DWT. It is applied basically the Haar, Daub4 and Coiflet wavelets transforms. Indeed, the sub signal am cumulates the energy, for this work of order 96% of the original signal ψ. A thresholding algorithm provides treatment for the noise, with significant reduction in the compressed signal. Then, it is established a comparison with a base of data in order to identify the perturbed signal. After the identification, it is recomposed the signal applying the inverse DWT. Many assumptions can be established: the rate signal-to-noise is properly high, the base of data must contain so many perturbed signals all with the same level of compression. The problem considered is for perturbations in the signal. For measurements the problem is similar, but in this case the unknown perturbations are generated by the apparatus of measurements, problems in experimental techniques, or simply by random noises. With the same above assumptions, the DWT is applied. For the identification, it is used a method evolving statistical and metric techniques. It is given some results obtained with an algebraic computer system.
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MA, J. F., and H. Q. WANG. "THE SPEECH ANALYSIS AND SEGMENTATION BY DISCRETE WAVELET TRANSFORM (DWT)." In Proceedings of the Third International Conference on WAA. World Scientific Publishing Company, 2003. http://dx.doi.org/10.1142/9789812796769_0010.

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Jenkal, Wissam, Rachid Latif, Ahmed Toumanari, Azdine Dliou, and Oussama El B'charri. "Enhanced algorithm for QRS detection using discrete wavelet transform (DWT)." In 2015 27th International Conference on Microelectronics (ICM). IEEE, 2015. http://dx.doi.org/10.1109/icm.2015.7437982.

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Rajasekhar, V., V. Vaishnavi, J. Koushik, and M. Thamarai. "An efficient image compression technique using discrete wavelet transform (DWT)." In 2014 International Conference on Electronics and Communication Systems (ICECS). IEEE, 2014. http://dx.doi.org/10.1109/ecs.2014.6892826.

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Kumari, T. Mita, and Gayadhar Panda. "Ownership Identification using Discrete Wavelet Transform (DWT)-based LOGO Watermarking." In Proceedings of the International Conference on Advances in Computer Science and Electronics Engineering. Singapore: Research Publishing Services, 2012. http://dx.doi.org/10.3850/978-981-07-1403-1_107.

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Reports on the topic "Discrete wavelet transform (DWT)"

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Shensa, M. J. The Discrete Wavelet Transform. Fort Belvoir, VA: Defense Technical Information Center, June 1991. http://dx.doi.org/10.21236/ada239642.

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Elofson, C. The Discrete Wavelet Transform with Lifting : A Step by Step Introduction. Office of Scientific and Technical Information (OSTI), August 2004. http://dx.doi.org/10.2172/15014818.

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Lojzim, Joshua Michael, and Marcus Fries. Brain Tumor Segmentation Using Morphological Processing and the Discrete Wavelet Transform. Journal of Young Investigators, August 2017. http://dx.doi.org/10.22186/jyi.33.3.55-62.

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Derbentsev, V., A. Ganchuk, and Володимир Миколайович Соловйов. Cross correlations and multifractal properties of Ukraine stock market. Politecnico di Torino, 2006. http://dx.doi.org/10.31812/0564/1117.

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Recently the statistical characterizations of financial markets based on physics concepts and methods attract considerable attentions. The correlation matrix formalism and concept of multifractality are used to study temporal aspects of the Ukraine Stock Market evolution. Random matrix theory (RMT) is carried out using daily returns of 431 stocks extracted from database time series of prices the First Stock Trade System index (www.kinto.com) for the ten-year period 1997-2006. We find that a majority of the eigenvalues of C fall within the RMT bounds for the eigenvalues of random correlation matrices. We test the eigenvalues of C within the RMT bound for universal properties of random matrices and find good agreement with the results for the Gaussian orthogonal ensemble of random matrices—implying a large degree of randomness in the measured cross-correlation coefficients. Further, we find that the distribution of eigenvector components for the eigenvectors corresponding to the eigenvalues outside the RMT bound display systematic deviations from the RMT prediction. We analyze the components of the deviating eigenvectors and find that the largest eigenvalue corresponds to an influence common to all stocks. Our analysis of the remaining deviating eigenvectors shows distinct groups, whose identities correspond to conventionally identified business sectors. Comparison with the Mantegna minimum spanning trees method gives a satisfactory consent. The found out the pseudoeffects related to the artificial unchanging areas of price series come into question We used two possible procedures of analyzing multifractal properties of a time series. The first one uses the continuous wavelet transform and extracts scaling exponents from the wavelet transform amplitudes over all scales. The second method is the multifractal version of the detrended fluctuation analysis method (MF-DFA). The multifractality of a time series we analysed by means of the difference of values singularity stregth (or Holder exponent) ®max and ®min as a suitable way to characterise multifractality. Singularity spectrum calculated from daily returns using a sliding 250 day time window in discrete steps of 1. . . 10 days. We discovered that changes in the multifractal spectrum display distinctive pattern around significant “drawdowns”. Finally, we discuss applications to the construction of crushes precursors at the financial markets.
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