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ASIC Design of DA-Based 2-D Inverse Discrete Cosine Transform
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作者 陈禾 韩月秋 《Journal of Beijing Institute of Technology》 EI CAS 1999年第2期56-63,共8页
Aim To present an ASIC design of DA based 2 D IDCT. Methods\ In the design of 1 D IDCT is utilized a Chen based fast IDCT algorithm, and multiplier accumulators based on distributed algorithm contributes in reduc... Aim To present an ASIC design of DA based 2 D IDCT. Methods\ In the design of 1 D IDCT is utilized a Chen based fast IDCT algorithm, and multiplier accumulators based on distributed algorithm contributes in reducing the hardware amount and in enhancing the speed performance. Results and Conclusion\ VHDL simulation, synthesis and layout design of system are implemented. This 2 D IDCT ASIC design owns best timing performance when compared with other better designs internationally. Results of design prove to be excellent. 展开更多
关键词 discrete cosine transform(DCT) distributed algorithm(DA) VHSIC hardware description language(VHDL)
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Audio Zero-Watermark Scheme Based on Discrete Cosine Transform-Discrete Wavelet TransformSingular Value Decomposition 被引量:7
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作者 Min Lei Yu Yang +2 位作者 XiaoMing Liu MingZhi Cheng Rui Wang 《China Communications》 SCIE CSCD 2016年第7期117-121,共5页
Traditional watermark embedding schemes inevitably modify the data in a host audio signal and lead to the degradation of the host signal.In this paper,a novel audio zero-watermarking algorithm based on discrete wavele... Traditional watermark embedding schemes inevitably modify the data in a host audio signal and lead to the degradation of the host signal.In this paper,a novel audio zero-watermarking algorithm based on discrete wavelet transform(DWT),discrete cosine transform(DCT),and singular value decomposition(SVD) is presented.The watermark is registered by performing SVD on the coefficients generated through DWT and DCT to avoid data modification and host signal degradation.Simulation results show that the proposed zero-watermarking algorithm is strongly robust to common signal processing methods such as requantization,MP3 compression,resampling,addition of white Gaussian noise,and low-pass filtering. 展开更多
关键词 zero-watermark discrete wavelet transform discrete cosine transform singular value decomposition
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A color image encryption scheme based on a 2D coupled chaotic system and diagonal scrambling algorithm
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作者 苏静明 方士辉 +1 位作者 洪炎 温言 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期233-243,共11页
A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are con... A novel color image encryption scheme is developed to enhance the security of encryption without increasing the complexity. Firstly, the plain color image is decomposed into three grayscale plain images, which are converted into the frequency domain coefficient matrices(FDCM) with discrete cosine transform(DCT) operation. After that, a twodimensional(2D) coupled chaotic system is developed and used to generate one group of embedded matrices and another group of encryption matrices, respectively. The embedded matrices are integrated with the FDCM to fulfill the frequency domain encryption, and then the inverse DCT processing is implemented to recover the spatial domain signal. Eventually,under the function of the encryption matrices and the proposed diagonal scrambling algorithm, the final color ciphertext is obtained. The experimental results show that the proposed method can not only ensure efficient encryption but also satisfy various sizes of image encryption. Besides, it has better performance than other similar techniques in statistical feature analysis, such as key space, key sensitivity, anti-differential attack, information entropy, noise attack, etc. 展开更多
关键词 color image encryption discrete cosine transform two-dimensional(2D)coupled chaotic system diagonal scrambling
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Performance Comparison of DCT and VQ Based Techniques for Iris Recognition 被引量:2
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作者 H.B.Kekre Tanuja K. Sarode +3 位作者 Vinayak Ashok Bharadi Abhishek A. Agrawal Rohan J. Arora Mahesh C. Nair 《Journal of Electronic Science and Technology》 CAS 2010年第3期223-229,共7页
Iris recognition enjoys universality, high degree of uniqueness and moderate user co-operation. This makes iris recognition systems unavoidable in emerging security & authentication mechanisms. An iris recognition sy... Iris recognition enjoys universality, high degree of uniqueness and moderate user co-operation. This makes iris recognition systems unavoidable in emerging security & authentication mechanisms. An iris recognition system based on vector quantization (VQ) techniques is proposed and its performance is compared with the discrete cosine transform (DCT). The proposed system does not need any pre-processing and segmentation of the iris. We have tested Linde-Buzo- Gray (LBG), Kekre's proportionate error (KPE) algorithm and Kekre's fast codebook generation (KFCG) algorithm for the clustering purpose. Proposed vector quantization based method using KFCG requires 99.99% less computations as that of full 2-dimensional DCT. Further, the KFCG method gives better performance with the accuracy of 89.10% outperforming DCT that gives accuracy around 66.10%. 展开更多
关键词 BIOMETRICS discrete cosine transform iris recognition Kekre's fast codebook generation Kekre's proportionate error Linde Buzonad Gray vector quantization.
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Novel Zero-Watermarking Scheme Based on DWT-DCT 被引量:3
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作者 Yu Yang Min Lei +2 位作者 Xiaoming Liu Zhiguo Qu Cheng Wang 《China Communications》 SCIE CSCD 2016年第7期122-126,共5页
Essential characteristics for watermark registration and detection without data modification can be used in anaudio zero-watermarking scheme.In this paper,a novel audio zero-watermarking scheme based on discrete wavel... Essential characteristics for watermark registration and detection without data modification can be used in anaudio zero-watermarking scheme.In this paper,a novel audio zero-watermarking scheme based on discrete wavelet transform(DWT) and discrete cosine transform(DCT) is presented.Thewatermark is registered by comparing the mean absolute values of the adjacent frame coefficients after DWT and DCT.Simulation results show that the proposed scheme is stronglyrobusttocommon attacks such as AWGN,downsampling,low-pass filtering,requantization,and MP3 compression.A performance analysis of the proposed scheme shows that all bit error rates after attacks are zero. 展开更多
关键词 zero-watermark discrete wavelets transform discrete cosine transform
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Decoder-based transient signal post-processing for ITU-T G.719 at low bit rate
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作者 王晶 纪璇 +1 位作者 何海龙 匡镜明 《Journal of Beijing Institute of Technology》 EI CAS 2012年第3期370-375,共6页
Associated with ITU-T G.719,a post-processing method in frequency domain for enhancing the perceptual quality of the decoded transient audio is proposed only to the audio decoder with no side information from the enco... Associated with ITU-T G.719,a post-processing method in frequency domain for enhancing the perceptual quality of the decoded transient audio is proposed only to the audio decoder with no side information from the encoder.The proposed post-filter is used to filter the frequency coefficients of the decoded transient frame and consists of a short-term post-filter and a spectral tilt compensation filter which are derived from linear predictive coding(LPC) predictor based on the discrete cosine transform(DCT) coefficients of the decoded transient frame.As a result,the post-filter in frequency domain shapes the temporal noise in time domain and controls the pre-echo noise effectively while enhancing the transient perception.Listening test results show that the preferring ratio of the post-processed transient signal is higher than that of the original decoded signal at a low bit rate of 32 kbit/s in G.719 and the post-processing module brings a complexity of 12.399 WMOPS to the decoder. 展开更多
关键词 transient audio discrete cosine transform(DCT) post-filter in frequency domain short-term post-filter spectral tilter compensation filter
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