• Title/Summary/Keyword: Discrete wavelet transform (DWT)

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Analysis of 2-Dimensional Object Recognition Using discrete Wavelet Transform (이산 웨이브렛 변환을 이용한 2차원 물체 인식에 관한 연구)

  • Park, Kwang-Ho;Kim, Chang-Gu;Kee, Chang-Doo
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.10
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    • pp.194-202
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    • 1999
  • A method for pattern recognition based on wavelet transform is proposed in this paper. The boundary of the object to be recognized includes shape information for object of machine parts. The contour is first represented using a one-dimensional signal and normalized about translation, rotation and scale, then is used to build the wavelet transform representation of the object. Wavelets allow us to decompose a function into multi-resolution hierarchy of localized frequency bands. The recognition of 2-dimensional object based on the wavelet is described to analyze the shape of analysis technique; the discrete wavelet transform(DWT). The feature vectors obtained using wavelet analysis is classified using a multi-layer neural network. The results show that, compared with the use of fourier descriptors, recognition using wavelet is more stable and efficient representation. And particularly the performance for objects corrupted with noise is better than that of other method.

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A High Speed 2D-DWT Parallel Hardware Architecture Using the Lifting Scheme (Lifting scheme을 이용한 고속 병렬 2D-DWT 하드웨어 구조)

  • 김종욱;정정화
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.7
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    • pp.518-525
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    • 2003
  • In this paper, we present a fast hardware architecture to implement a parallel 2-dimensional discrete wavelet transform(DWT)based on the lifting scheme DWT framework. The conventional 2-D DWT had a long initial and total latencies to get the final 2D transformed coefficients because the DWT used an entire input data set for the transformation and transformed sequentially The proposed architecture increased the parallel performance at computing the row directional transform using new data splitting method. And, we used the hardware resource sharing architecture for improving the total throughput of 2D DWT. Finally, we proposed a scheduling of hardware resource which is optimized to the proposed hardware architecture and splitting method. Due to the use of the proposed architecture, the parallel computing efficiency is increased. This architecture shows the initial and total latencies are improved by 50% and 66%.

Blind Color Image Watermarking Based on DWT and LU Decomposition

  • Wang, Dongyan;Yang, Fanfan;Zhang, Heng
    • Journal of Information Processing Systems
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    • v.12 no.4
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    • pp.765-778
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    • 2016
  • In watermarking schemes, the discrete wavelet transform (DWT) is broadly used because its frequency component separation is very useful. Moreover, LU decomposition has little influence on the visual quality of the watermark. Hence, in this paper, a novel blind watermark algorithm is presented based on LU transform and DWT for the copyright protection of digital images. In this algorithm, the color host image is first performed with DWT. Then, the horizontal and vertical diagonal high frequency components are extracted from the wavelet domain, and the sub-images are divided into $4{\times}4$ non-overlapping image blocks. Next, each sub-block is performed with LU decomposition. Finally, the color image watermark is transformed by Arnold permutation, and then it is inserted into the upper triangular matrix. The experimental results imply that this algorithm has good features of invisibility and it is robust against different attacks to a certain degree, such as contrast adjustment, JPEG compression, salt and pepper noise, cropping, and Gaussian noise.

LBP and DWT Based Fragile Watermarking for Image Authentication

  • Wang, Chengyou;Zhang, Heng;Zhou, Xiao
    • Journal of Information Processing Systems
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    • v.14 no.3
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    • pp.666-679
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    • 2018
  • The discrete wavelet transform (DWT) has good multi-resolution decomposition characteristic and its low frequency component contains the basic information of an image. Based on this, a fragile watermarking using the local binary pattern (LBP) and DWT is proposed for image authentication. In this method, the LBP pattern of low frequency wavelet coefficients is adopted as a feature watermark, and it is inserted into the least significant bit (LSB) of the maximum pixel value in each block of host image. To guarantee the safety of the proposed algorithm, the logistic map is applied to encrypt the watermark. In addition, the locations of the maximum pixel values are stored in advance, which will be used to extract watermark on the receiving side. Due to the use of DWT, the watermarked image generated by the proposed scheme has high visual quality. Compared with other state-of-the-art watermarking methods, experimental results manifest that the proposed algorithm not only has lower watermark payloads, but also achieves good performance in tamper identification and localization for various attacks.

Low-power DWT filter bank design using comb filter and fourth-order polynomial (Comb 필터와 4차 다항식을 사용한 저전력 DWT 필터뱅크 설계)

  • Jang Young-Beom;Lee Won-Sang
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.1
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    • pp.87-94
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    • 2005
  • In this paper a low-power DWT(Discrete Wavelet Transform) design technique is proposed. As basic low-pass filter for analysis bank, comb filter is utilized, and in order to improve frequency response for the comb filter, a fourth order polynomial is also proposed. Another filters are designed by using perfect reconstruction conditions. The lowpass filter coefficients of the analysis filter bank are optimized based on the cost function and perfect reconstruction condition. The number of the multiplications and MSE(Mean Squared Error) performance of the proposed DWT filter bank are compared with those of the JPEG2000 (9, 7) filter bank. It is shown that number of multiplications of the proposed filter bank are saved with 33.3%, and MSE values of the proposed filter bank are also superior to those of the JPEG2000 (9, 7) filter bank.

Detection of Premature Ventricular Contraction Using Discrete Wavelet Transform and Fuzzy Neural Network (이산 웨이블릿 변환과 퍼지 신경망을 이용한 조기심실수축 추출)

  • Jang, Hyoung-Jong;Lim, Joon-Shik
    • Journal of Korea Multimedia Society
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    • v.12 no.3
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    • pp.451-459
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    • 2009
  • This paper presents an approach to detect premature ventricular contraction(PVC) using discrete wavelet transform and fuzzy neural network. As the input of the algorithm, we use 14 coefficients of d3, d4, and d5, which are transformed by a discrete wavelet transform(DWT). This paper uses a neural network with weighted fuzzy membership functions(NEWFM) to diagnose PVC. The NEWFM discussed in this paper classifies a normal beat and a PVC beat. The size of the window of DWT is $-31/360{\sim}+32/360$ second(64 samples) whose center is the R wave. Using the seven records of the MIT-BIH arrhythmia database used in Shyu's paper, the classification performance of the proposed algorithm is 99.91%, which outperforms the 97.04% of Shyu's analysis. Using the forty records of the M1T-BIH arrhythmia database used in Inan's paper, the classification performance of the proposed algorithm is 98.01%, which outperforms 96.85% of Inan's one. The SE and SP of the proposed algorithm are 84.67% and 99.39%, which outperforms the 82.57% and 98.33%, respectively, of Inan's study.

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Digital Watermarking for JPEG2000 (JPEG2000을 위한 디지털 워터마킹)

  • 서용석;주상현;정호열
    • Journal of Broadcast Engineering
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    • v.6 no.1
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    • pp.32-40
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    • 2001
  • In this paper, we propose a DWT (discrete Wavelet Transform) based watermarking method, which can be conveniently Integrated In the up-coming JPEG2770 baseline system. Although Conventional DWT based watermarking techniques insert watermark signal Into wavelet coefficients after the transform, our proposed method embeds a watermark into wavelet coefficients obtained from the ongoing process of lifting for DWT. The proposed method allows us to selectively determine frequency characteristics of the coefficients where the watermark is embedded. so that the Inserted watermark cannot be removed or altered even when the filter-bank for DWT is known. Through the simulation, we show that the proposed method is more secure and more robust against various attacks than conventional DWT barred watermarking techniques.

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Channel Equalization for QAM Signal Constellation Using Wavelet Transform and Neural Network

  • Lee, Seok-Won;Nam, Boo-Hee
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.147-147
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    • 2000
  • Recently, a considerable amount of attention is being given to the use of wavelets and neural network for modulation and equalization. We proposed a new scheme of equalization for constellation using discrete wavelet transform(DWT) and neural network. The DWT is used for noise reduction and the neural network is used to update the equalizer coefficients adaptively.

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Feature values of DWT using MR general imaging and molecular imaging (DWT를 이용한 MR 일반영상과 분자영상 특징추출)

  • Pack, Dae-Sung;Choi, Gui-Rack;Han, Byung-Sung;Ahn, Byung-Ju
    • Journal of the Korean Society of Radiology
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    • v.6 no.5
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    • pp.409-414
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    • 2012
  • This study acquired molecular lmaging using nano-contrast agents, and the general condition of the same image acquisition to analyze the difference between molecular imaging and general imaging, two images are converted into DWT (Discrete Wavelet Transform). Nano-contrast agent imaging using MRI and molecular imaging using PET study of molecular imaging technology mainstream. DWT analysis of the same lesions using MRI imaging and molecular imaging block lesions are present in the lesions, illustrating the value of a high-frequency feature both highly general imaging and molecular imaging could know that. The high frequency region of the feature extraction values appear higher molecular imaging.

Super-resolution method for Infra-red Images (적외선 영상을 위한 초고해상도 기법)

  • Kim, Young-doo;Choi, Hyun-jun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.540-541
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    • 2018
  • In this paper, we propose an super-resolution method that improves resolution by using DWT (Discrete Wavelet Transform) for low resolution infra-red images. In this method, DWT is performed in a manner that does not reduce the resolution of an image input through an infra-red camera to generate sub-bands of the same resolution (LH, HL, and HH) And the original infra-red image is used to perform an inverse-DWT to obtain an infra-red image with improved resolution. Experimental results show that the mean SSIM value of the proposed method is 0.989861, which is about 0.004 higher than that of the conventional Bi-linear and Bi-cubic filters.

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