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The gap between principle and practice of lossy image coding 认领 引用
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作者 Haotian Zhang Dong Liu 《Journal of University of Science and Technology of China》 CAS CSCD 北大核心 2026年第1期1-12,I0001,共12页
Lossy image coding is the art of computing that is principally bounded by the image’s rate-distortion function.This bound,though never accurately characterized,has been approached practically via deep learning techno... Lossy image coding is the art of computing that is principally bounded by the image’s rate-distortion function.This bound,though never accurately characterized,has been approached practically via deep learning technologies in recent years.Indeed,learned image coding schemes allow direct optimization of the joint rate-distortion cost,thereby outperforming the handcrafted image coding schemes by a large margin.Still,it is observed that there is room for further improvement in the rate-distortion performance of learned image coding.In this article,we identify the gap between the ideal rate-distortion function forecasted by Shannon’s information theory and the empirical rate-distortion function achieved by the state-of-the-art learned image coding schemes,revealing that the gap is incurred by five different effects:modeling effect,approximation effect,amortization effect,digitization effect,and asymptotic effect.We design simulations and experiments to quantitatively evaluate the last three effects,which demonstrates the high potential of future lossy image coding technologies. 展开更多
关键词 information theory learned image coding lossy image coding rate-distortion function
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Chaos-based encryption for fractal image coding 认领 引用 被引量：10
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作者 袁正雄 黄国和 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第1期115-126,共12页
A chaos-based cryptosystem for fractal image coding is proposed. The Renyi chaotic map is employed to determine the order of processing the range blocks and to generate the keystream for masking the encoded sequence. ... A chaos-based cryptosystem for fractal image coding is proposed. The Renyi chaotic map is employed to determine the order of processing the range blocks and to generate the keystream for masking the encoded sequence. Compared with the standard approach of fraetal image coding followed by the Advanced Encryption Standard, our scheme offers a higher sensitivity to both plaintext and ciphertext at a comparable operating efficiency. The keystream generated by the Renyi chaotic map passes the randomness tests set by the United States National Institute of Standards and Technology, and so the proposed scheme is sensitive to the key. 展开更多
关键词 chaos cryptography joint image compression and encryption fractal image coding
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Mean shift based log-Gabor wavelet image coding 认领 引用 被引量：2
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作者 LI Ji-liang FANG Xiang-zhong HOU Jun 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS 2007年第4期620-624,共5页
In this paper, we propose a sparse overcomplete image approximation method based on the ideas of overcomplete log-Gabor wavelet, mean shift and energy concentration. The proposed approximation method selects the neces... In this paper, we propose a sparse overcomplete image approximation method based on the ideas of overcomplete log-Gabor wavelet, mean shift and energy concentration. The proposed approximation method selects the necessary wavelet coefficients with a mean shift based algorithm, and concentrates energy on the selected coefficients. It can sparsely approximate the original image, and converges faster than the existing local competition based method. Then, we propose a new compression scheme based on the above approximation method. The scheme has compression performance similar to JPEG 2000. The images decoded with the proposed compression scheme appear more pleasant to the human eyes than those with JPEG 2000. 展开更多
关键词 Sparse approximation Log-Gabor Image coding Mean shift Overcomolete
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High performance scalable image coding 认领 引用
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作者 Gan Tao He Yanmin Zhu Weile 《Journal of Systems Engineering and Electronics》 SCIE EI 2007年第4期795-800,共6页
A high performance scalable image coding algorithm is proposed.The salient features of this algorithm are the ways to form and locate the significant clusters.Thanks to the list structure,the new coding algorithm achi... A high performance scalable image coding algorithm is proposed.The salient features of this algorithm are the ways to form and locate the significant clusters.Thanks to the list structure,the new coding algorithm achieves fine fractional bit-plane coding with negligible additional complexity.Experiments show that it performs comparably or better than the state-of-the-art coders.Furthermore,the flexible codec supports both quality and resolution scalability,which is very attractive in many network applications. 展开更多
关键词 scalable image coding significant clusters list structure
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An Adaptive Block-Based Fractal Image Coding Scheme 认领 引用
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作者 邓元木 柯有安 《Journal of Beijing Institute of Technology》 EI CAS 1996年第2期183+177-183,共184页
Based on Jacquin's work. this paper presents an adaptive block-based fractal image coding scheme. Firstly. masking functions are used to classify range blocks and weight the mean Square error (MSE) of images. Seco... Based on Jacquin's work. this paper presents an adaptive block-based fractal image coding scheme. Firstly. masking functions are used to classify range blocks and weight the mean Square error (MSE) of images. Secondly, an adaptive block partition scheme is introduced by developing the quadtree partition method. Thirdly. a piecewise uniform quantization strategy is appled to quantize the luminance shifting. Finally. experiment results are shown and compared with what reported by Jacquin and Lu to verify the validity of the methods addressed by the authors. 展开更多
关键词 fractal technique image compression image coding
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REMOTE SENSING IMAGE CODING METHOD COMBINING WAVELET TRANSFORM WITH CLASSIFIED VECTOR QUANTIZATION 认领 引用
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作者 张正阳 吴成柯 《Chinese Journal of Aeronautics》 CAS 1998年第3期55-60,共6页
A new remote sensing image coding scheme based on the wavelet transform and classified vector quantization (CVQ) is proposed. The original image is first decomposed into a hierarchy of 3 layers including 10 subimages ... A new remote sensing image coding scheme based on the wavelet transform and classified vector quantization (CVQ) is proposed. The original image is first decomposed into a hierarchy of 3 layers including 10 subimages by DWT. The lowest frequency subimage is compressed by scalar quantization and ADPCM. The high frequency subimages are compressed by CVQ to utilize the similarity among different resolutions while improving the edge quality and reducing computational complexity. The experimental results show that the proposed scheme has a better performance than JPEG, and a PSNR of reconstructed image is 31～33 dB with a rate of 0.2 bpp. 展开更多
关键词 remote sensing image coding wavelet transform classified vector quantization
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Efficient Quadtree based Fractal Image Coding Scheme in Wavelet Transform Domain * 认领 引用
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作者 高西奇 洪波 +1 位作者 张辉 何振亚 《Journal of Southeast University(English Edition)》 CAS 1998年第1期35-40,共6页
This paper presents an efficient quadtree based fractal image coding scheme in wavelet transform domain based on the wavelet based theory of fractal image compression introduced by Davis. In the scheme, zerotrees of w... This paper presents an efficient quadtree based fractal image coding scheme in wavelet transform domain based on the wavelet based theory of fractal image compression introduced by Davis. In the scheme, zerotrees of wavelet coefficients are used to reduce the number of domain blocks, which leads to lower bit cost required to represent the location information of fractal coding, and overall entropy constrained optimization is performed for the decision trees as well as for the sets of scalar quantizers and self quantizers of wavelet subtrees. Experiment results show that at the low bit rates, the proposed scheme gives about 1 dB improvement in PSNR over the reported results. 展开更多
关键词 fractal image coding wavelet transform quadtree
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A HIGH SPEED ADAPTIVE FRACTAL IMAGE CODING ALGORITHM USING FLEXIBLE CLASSIFICATION TECHNIQUE 认领 引用
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作者 Zhang Liang Li Weihua Wang Qiao 《Wuhan University Journal of Natural Sciences》 EI CAS 1998年第2期146-146,共1页
Traditionally, fractal image compression suffers from lengthy encoding time in measure ofhours. In this paper, combined with characteristlcs of human visual system, a flexible classification technique is proposed. Thi... Traditionally, fractal image compression suffers from lengthy encoding time in measure ofhours. In this paper, combined with characteristlcs of human visual system, a flexible classification technique is proposed. This yields a corresponding adaptive algorithm which can cut down the encoding timeinto second's magnitude. Experiment results suggest that the algorithm can balance the overall encodingperformance efficiently, that is, with a higher speed and a better PSNR gain. 展开更多
关键词 image coding fractal image coding iterated function system (IFS) partitioned iterated function system (PIFS) characteristics of human visual system
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Technique of Error Concealment for Block-Based Image Coding Using Genetic Algorithm 认领 引用 被引量：1
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作者 杨守义 罗伟雄 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期164-168,共5页
Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborhood... Since real world communication channels are not error free, the coded data transmitted on them may be corrupted, and block based image coding systems are vulnerable to transmission impairment. So the best neighborhood match method using genetic algorithm is used to conceal the error blocks. Experimental results show that the searching space can be greatly reduced by using genetic algorithm compared with exhaustive searching method, and good image quality is achieved. The peak signal noise ratios(PSNRs) of the restored images are increased greatly. 展开更多
关键词 block based image coding genetic algorithm error concealment
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Lifting Scheme Based SPIHT Still Image Coding 认领 引用
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作者 沈利军 赵保军 何佩琨 《Journal of Beijing Institute of Technology》 EI CAS 2003年第S1期70-74,共5页
In order to eliminate float-point operations for fast wavelet transform, an integer D9/7 biorthogonal reversible wavelet transform was accomplished by lifting scheme. The lifting scheme based wavelet transform can be ... In order to eliminate float-point operations for fast wavelet transform, an integer D9/7 biorthogonal reversible wavelet transform was accomplished by lifting scheme. The lifting scheme based wavelet transform can be finished by addition and shift simply. It improved the quality of reconstructive image and greatly reduced the computational complexity due to integer operation. It is suitable for real-time image coding on hardware such as DSP. The simulation results show that the lifting scheme based SPIHT is prior to traditional wavelet based SPHIT in quality and complexity. 展开更多
关键词 SPIHT lifting scheme wavelet image coding
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Fast 2-D 8×8 discrete cosine transform algorithm for image coding 认领 引用 被引量：1
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作者 JI XiuHua ZHANG CaiMing +1 位作者 WANG JiaYe BOEY S. H. 《Science in China(Series F)》 2009年第2期215-225,共11页
A new fast two-dimension 8×8 discrete cosine transform （2D 8×8 DCT） algorithm based on the characteristics of the basic images of 2D DCT is presented. The new algorithm computes each DCT coefficient in tur... A new fast two-dimension 8×8 discrete cosine transform （2D 8×8 DCT） algorithm based on the characteristics of the basic images of 2D DCT is presented. The new algorithm computes each DCT coefficient in turn more independently. Hence, the new algorithm is suitable for 2D DCT pruning algorithm of pruning away any number of high-frequency components of 2D DCT. The proposed pruning algorithm is more efficient than the existing pruning 2D DCT algorithms in terms of the number of arithmetic operations, especially the number of multiplications required in the computation. 展开更多
关键词 discrete cosine transform basic image quantization image coding
SFNIC:Hybrid Spatial-Frequency Information for Lightweight Neural Image Compression 认领 引用 被引量：1
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作者 Youneng Bao Wen Tan +3 位作者 Mu Li Jiacong Chen Qingyu Mao Yongsheng Liang 《CAAI Transactions on Intelligence Technology》 SCIE EI CSCD 2025年第6期1717-1730,共14页
Neural image compression(NIC)has shown remarkable rate-distortion(R-D)efficiency.However,the considerable computational and spatial complexity of most NIC methods presents deployment challenges on resource-constrained... Neural image compression(NIC)has shown remarkable rate-distortion(R-D)efficiency.However,the considerable computational and spatial complexity of most NIC methods presents deployment challenges on resource-constrained devices.We introduce a lightweight neural image compression framework designed to efficiently process both local and global information.In this framework,the convolutional branch extracts local information,whereas the frequency domain branch extracts global information.To capture global information without the high computational costs of dense pixel operations,such as attention mechanisms,Fourier transform is employed.This approach allows for the manipulation of global information in the frequency domain.Additionally,we employ feature shift operations as a strategy to acquire large receptive fields without any computational cost,thus circumventing the need for large kernel convolution.Our framework achieves a superior balance between ratedistortion performance and complexity.On varying resolution sets,our method not only achieves rate-distortion(R-D)performance on par with versatile video coding(VVC)intra and other state-of-the-art(SOTA)NIC methods but also exhibits the lowest computational requirements,with approximately 200 KMACs/pixel.The code will be available at http://gffzz188fe103f8f1460as5oobxuqqwbwp6fwv.ffgz.tsg.suse.edu.cn/baoyu2020/SFNIC. 展开更多
关键词 deep learning image coding neural network video coding
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Combining IFS and VQ in Fractal Image Coding 认领 引用 被引量：5
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作者 HUANG Yi, SUN Hai-an 《The Journal of China Universities of Posts and Telecommunications》 2000年第1期26-30,共5页
A novel paradigm for fractal coding selectively corrects the fractal code for selected domain blocks with an image-adaptive VQ codebook. The codebook is generated from the initial uncorrected fractal code and is, ther... A novel paradigm for fractal coding selectively corrects the fractal code for selected domain blocks with an image-adaptive VQ codebook. The codebook is generated from the initial uncorrected fractal code and is, therefore, available at the decoder. An efficient trade-off is generated between incremental performance and bit rate. 展开更多
关键词 fractal image coding vector quantization interacted function systems
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FAST IMAGE ENCODING ALGORITHM BASED ON MEAN-MATCH CORRELATION VECTOR QUANTIZATION 认领 引用 被引量：1
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作者 徐润生 许晓鸣 张卫东 《Journal of Shanghai Jiaotong university(Science)》 2001年第1期40-43,共4页
A mean-match correlation vector quantizer (MMCVQ) was presented for fast image encoding. In this algorithm, a sorted codebook is generated regarding the mean values of all codewords. During the encoding stage, high co... A mean-match correlation vector quantizer (MMCVQ) was presented for fast image encoding. In this algorithm, a sorted codebook is generated regarding the mean values of all codewords. During the encoding stage, high correlation of the adjacent image blocks is utilized, and a searching range is obtained in the sorted codebook according to the mean value of the current processing vector. In order to gain good performance, proper THd and NS are predefined on the basis of experimental experiences and additional distortion limitation. The expermental results show that the MMCVQ algorithm is much faster than the full-search VQ algorithm, and the encoding quality degradation of the proposed algorithm is only 0.3～0.4 dB compared to the full-search VQ. 展开更多
关键词 image coding vector quantization mean match method
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A New Image Coding Algorithm Based on Self-Organizing Neural Network 认领 引用 被引量：1
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作者 Li Hongsong Quan Ziyi 《The Journal of China Universities of Posts and Telecommunications》 1995年第1期40-43,共4页
The paper deals with a new VQ+DPCM+DCT algorithm based on Self-Organizing Feature Maps(SOFM)algorithm for image coding.In addition.a Frequency sensitive SOFM(FSOFM)has been also devel-oped.Simulation results show that... The paper deals with a new VQ+DPCM+DCT algorithm based on Self-Organizing Feature Maps(SOFM)algorithm for image coding.In addition.a Frequency sensitive SOFM(FSOFM)has been also devel-oped.Simulation results show that a very good visual quality of the coded image at 0.252 bits/pixel is obtained. 展开更多
关键词 image coding vector quantization(VQ),self-organizing neural network
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Wavelet-Based Mixed-Resolution Coding Approach Incorporating with SPT for the Stereo Image 认领 引用
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作者 Xu, C. Zhang, Z. An, P. 《Journal of Systems Engineering and Electronics》 EI 2001年第3期39-44,共6页
With the advances of display technology, three-dimensional(3-D) imaging systems are becoming increasingly popular. One way of stimulating 3-D perception is to use stereo pairs, a pair of images of the same scene acqui... With the advances of display technology, three-dimensional(3-D) imaging systems are becoming increasingly popular. One way of stimulating 3-D perception is to use stereo pairs, a pair of images of the same scene acquired from different perspectives. Since there is an inherent redundancy between the images of a stereo pairs, data compression algorithms should be employed to represent stereo pairs efficiently. The proposed techniques generally use block-based disparity compensation. In order to get the higher compression ratio, this paper employs the wavelet-based mixed-resolution coding technique to incorporate with SPT-based disparity-compensation to compress the stereo image data. The mixed-resolution coding is a perceptually justified technique that is achieved by presenting one eye with a low-resolution image and the other with a high-resolution image. Psychophysical experiments show that the stereo image pairs with one high-resolution image and one low-resolution image provide almost the same stereo depth to that of a stereo image with two high-resolution images. By combining the mixed-resolution coding and SPT-based disparity-compensation techniques, one reference (left) high-resolution image can be compressed by a hierarchical wavelet transform followed by vector quantization and Huffman encoder. After two level wavelet decompositions, for the low-resolution right image and low-resolution left image, subspace projection technique using the fixed block size disparity compensation estimation is used. At the decoder, the low-resolution right subimage is estimated using the disparity from the low-resolution left subimage. A full-size reconstruction is obtained by upsampling a factor of 4 and reconstructing with the synthesis low pass filter. Finally, experimental results are presented, which show that our scheme achieves a PSNR gain (about 0.92dB) as compared to the current block-based disparity compensation coding techniques. 展开更多
关键词 Data reduction Decoding Image coding Image compression Image reconstruction Imaging techniques Motion compensation Motion estimation Optical resolving power Projection systems Stereo vision Wavelet transforms
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A Novel Coding Method Based on Fuzzy Vector Quantization for Noised Image 认领 引用
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作者 Li Yibing ,Lou Zhe, Jiang Tao & Si Xicai Dept. of Eledronic Eng., Harbin Engineering University 150001, P. R. China 《Journal of Systems Engineering and Electronics》 EI 2001年第2期87-91,共5页
In this paper a novel coding method based on fuzzy vector quantization for noised image with Gaussian white-noise pollution is presented. By restraining the high frequency subbands of wavelet image the noise is signif... In this paper a novel coding method based on fuzzy vector quantization for noised image with Gaussian white-noise pollution is presented. By restraining the high frequency subbands of wavelet image the noise is significantly removed and coded with fuzzy vector quantization. The experimental result shows that the method can not only achieve high compression ratio but also remove noise dramatically. 展开更多
关键词 Fuzzy sets Gaussian noise (electronic) Image coding Image compression Integral equations Vector quantization Wavelet transforms White noise
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LOW-COMPLEXITY REDUNDANCY INSERTION IN MULTIPLE DESCRIPTION CODING 认领 引用
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作者 Yang Rener Li Jinxiang Wen Huafeng 《Journal of Electronics(China)》 2008年第3期409-414,共6页
Multiple description coding has recently been proposed as a joint source and channel coding to solve the problem of robust image transmission over unreliable network, and it can offer a variety of tradeoff between sig... Multiple description coding has recently been proposed as a joint source and channel coding to solve the problem of robust image transmission over unreliable network, and it can offer a variety of tradeoff between signal redundancy and transmission robustness. In this letter, a novel pre- and post-processing method with flexible redundancy insertion for polyphase downsampling multiple de- scription coding is presented. The proposed method can be implemented as pre- and post-processing to all standards for image and video communications, with obvious advantages. Simulation results show that this approach can reduce the computational complexity while provide a flexible redundancy in- sertion to make the system robust for any packet loss situation over different networks. 展开更多
关键词 Multiple description image coding Polyphase downsampling Redundancy insertion
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Novel region-based image compression method based on spiking cortical model 认领 引用 被引量：1
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作者 Rongchang Zhao Yide Ma 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2015年第1期161-171,共11页
To get the high compression ratio as well as the high-quality reconstructed image, an effective image compression scheme named irregular segmentation region coding based on spiking cortical model（ISRCS） is presented... To get the high compression ratio as well as the high-quality reconstructed image, an effective image compression scheme named irregular segmentation region coding based on spiking cortical model（ISRCS） is presented. This scheme is region-based and mainly focuses on two issues. Firstly, an appropriate segmentation algorithm is developed to partition an image into some irregular regions and tidy contours, where the crucial regions corresponding to objects are retained and a lot of tiny parts are eliminated. The irregular regions and contours are coded using different methods respectively in the next step. The other issue is the coding method of contours where an efficient and novel chain code is employed. This scheme tries to find a compromise between the quality of reconstructed images and the compression ratio. Some principles and experiments are conducted and the results show its higher performance compared with other compression technologies, in terms of higher quality of reconstructed images, higher compression ratio and less time consuming. 展开更多
关键词 data compaction and compression image processing and computer vision region-based image coding neural network
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Polarization state and image rotation via spontaneously generated coherence in a spinning fast light medium 认领 引用
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作者 Habibur Rahman Mansoor Khan +3 位作者 Shabir Ahmad Muhammad Tayyab Haseena Bibi Hazrat Ali 《Communications in Theoretical Physics》 SCIE CAS CSCD 2020年第11期99-103,共5页
In this article we propose a four-level rubidium(Rb87)atomic system for observing interesting features of polarization state rotation in a fast light medium.We investigate spontaneously generated coherence(SGC)for a s... In this article we propose a four-level rubidium(Rb87)atomic system for observing interesting features of polarization state rotation in a fast light medium.We investigate spontaneously generated coherence(SGC)for a spinning medium.We show how SGC can affect different spectral profiles of the polarization state and images in this suggested model.We observe a 0.5 radian rotation and 2.5 microsecond time advancement in our proposed system.Our precise results will provide a new platform for researchers in quantum optics due to its applications in image coding,telecommunications and cloaking technology. 展开更多
关键词 spinning medium SGC effect image coding
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