Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface ho...Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface holography can only realize static manipulation.In this study,we propose and demonstrate a multiplexing metasurface technique combined with multiwavelength code-division multiplexing(CDM)to realize dynamic manipulation.Multicolor code references are utilized to record information within a single metasurface and increase the information capacity and security for anticracks.A total of 48 monochrome images consisting of pure color characters and multilevel color video frames were reconstructed in dual polarization channels of the birefringent metasurface to exhibit high information density,and a video was displayed via sequential illumination of the corresponding code patterns to verify the ability of dynamic manipulation.Our approach demonstrates significant application potential in optical data storage,optical encryption,multiwavelengthversatile diffractive optical elements,and stimulated emission depletion microscopy.展开更多
Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λ...Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.展开更多
We propose a new full color ghost imaging scheme using both time and code division multiplexing technologies.In the scheme,the speckle patterns of three colors(red,green and blue)are modulated with different time slot...We propose a new full color ghost imaging scheme using both time and code division multiplexing technologies.In the scheme,the speckle patterns of three colors(red,green and blue)are modulated with different time slots and codes.The light intensity is sampled by one bucket detector.Then based on the modulated time slots and codes,we can effectively and simultaneously extract three detection component signals corresponding to three color components of objects from the sampling signal of the bucket detector.Finally,three component images resulting from the three component detection signals can be synthesized into a full color image.The experimental results verify the feasibility of our scheme under the limit of the number of time slots and codes.Moreover,our scheme reduces the number of bucket detectors and can realize high quality imaging even in a noisy environment.展开更多
In this paper,hyperbolic geometry is used to constructing new quantum color codes.We use hyperbolic tessellations and hyperbolic polygons to obtain them by pairing the edges on compact surfaces.These codes have minimu...In this paper,hyperbolic geometry is used to constructing new quantum color codes.We use hyperbolic tessellations and hyperbolic polygons to obtain them by pairing the edges on compact surfaces.These codes have minimum distance of at least 4 and the encoding rate near to 1,which are not mentioned in other literature.Finally,a comparison table with quantum codes recently proposed by the authors is provided.展开更多
A new 3D surface contouring and ranging system based on digital fringe projection and phase shifting technique is presented. Using the phase-shift technique, points cloud with high spatial resolution and limited accur...A new 3D surface contouring and ranging system based on digital fringe projection and phase shifting technique is presented. Using the phase-shift technique, points cloud with high spatial resolution and limited accuracy can be generated. Stereo-pair images obtained from two cameras can be used to compute 3D world coordinates of a point using traditional active triangulation approach, yet the camera calibration is crucial. Neural network is a well-known approach to approximate a nonlinear system without an explicit physical model, in this work it is used to train the stereo vision application system to calculating 3D world coordinates such that the camera calibration can be bypassed. The training set for neural network consists of a variety of stereo-pair images and the corresponding 3D world coordinates. The picture elements correspondence problem is solved by using projected color-coded fringes with different orientations. Color imbalance is completely eliminated by the new color-coded method. Once the high accuracy correspondence of 2D images with 3D points is acquired, high precision 3D points cloud can be recognized by the well trained net. The obvious advantage of this approach is that high spatial resolution can be obtained by the phase-shifting technique and high accuracy 3D object point coordinates are achieved by the well trained net which is independent of the camera model works for any type of camera. Some experiments verified the performance of the method.展开更多
Structural colors based on metasurfaces have very promising applications in areas such as optical image encryption and color printing.Herein,we propose a deep learning-enabled reverse design of polarization-selective ...Structural colors based on metasurfaces have very promising applications in areas such as optical image encryption and color printing.Herein,we propose a deep learning-enabled reverse design of polarization-selective structural color based on coding metasurface.In this study,the long short-term memory(LSTM)neural network is presented to enable the forward and inverse mapping between coding metasurface structure and corresponding color.The results show that the method can achieve 98%accuracy for the forward prediction of color and 93%accuracy for the inverse design of the structure.Moreover,a cascaded architecture is adopted to train the inverse neural network model,which can solve the nonuniqueness problem of the polarization-selective color reverse design.This study provides a new path for the application and development of structural colors.展开更多
he objective of the research is to develop a fast procedure for segmenting typical videophone images. In this paper, a new approach to color image segmentation based on HSI(Hue, Saturation, Intensity) color model is r...he objective of the research is to develop a fast procedure for segmenting typical videophone images. In this paper, a new approach to color image segmentation based on HSI(Hue, Saturation, Intensity) color model is reported. It is in contrast to the conventional approaches by using the three components of HSI color model in succession. This strategy makes the segmentation procedure much fast and effective. Experimental results with typical “headandshoulders” real images taken from videophone sequences show that the new appproach can fulfill the application requirements.展开更多
In this paper,we propose a novel pseudo-color approach which can effectively mark all different particulars while it has the ability to divide foreign pieces with indiscernible brightness in fibre masses.Hence,it yiel...In this paper,we propose a novel pseudo-color approach which can effectively mark all different particulars while it has the ability to divide foreign pieces with indiscernible brightness in fibre masses.Hence,it yields highly separate color images for this kind of industrial images.Our approach aims at constructing an adaptive fuzzy rule based on a feature space of gradients,gray values,local entropies,and local features from scalable morphological filters.Due to the fact that the method is based on a full contextual information,it can handle small changes in images more adaptively than classical pseudo-color methods.And it is perfectly suitable to distinguish impurities mixed in fibre masses,as tested in a simulating cotton inspection system and demonstrated by several cotton sample images.展开更多
This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended ...This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.展开更多
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
A novel color compensation method for multi-view video coding (MVC) is proposed, which efficiently exploits the inter-view dependencies between views with the existence of color mismatch caused by the diversity of cam...A novel color compensation method for multi-view video coding (MVC) is proposed, which efficiently exploits the inter-view dependencies between views with the existence of color mismatch caused by the diversity of cameras. A color compensation model is developed in RGB channels and then extended to YCbCr channels for practical use. A modified inter-view reference picture is constructed based on the color compensation model, which is more similar to the coding picture than the original inter-view reference picture. Moreover, the color compensation factors can be derived in both encoder and decoder, therefore no additional data need to be transmitted to the decoder. The experimental results show that the proposed method improves the coding efficiency of MVC and maintains good subjective quality.展开更多
In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural o...In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural order in storage, our scheme requires 25 more memory blocks but allows a simpler configuration for variable sizes of code lengths that can be implemented on-chip. Experiment shows that for a moderate to high decoding throughput （40-100 Mbps）, the hardware cost is still affordable for 3GPP＇s （3rd generation partnership project） interleaver.展开更多
In this paper,a new type of edge coloring of graphs together with an algorithm for such an edge coloring is presented to construct some columnweight three low-density parity-check(LDPC)codes whose Tanner graphs are fr...In this paper,a new type of edge coloring of graphs together with an algorithm for such an edge coloring is presented to construct some columnweight three low-density parity-check(LDPC)codes whose Tanner graphs are free of 4-cycles.This kind of edge coloring is applied on some well-known classes of graphs such as complete graphs and complete bipartite graphs to generate some column-weight 3 LDPC codes having flexibility in terms of code length and rate.Interestingly,the constructed(3;k)-regular codes with regularities k=4;5;:::;22 have lengths n=12;20;26,35;48;57;70;88;104;117;140;155;176;204;228;247;280;301;330;having minimum block length compared to the best known similar codes in the literature.In addition to linear complexity of generating such parity-check matrices,they can be considered as the base matrices of some quasi-cyclic(QC)LDPC codes with maximum achievable girth 18,which inherit the low-complexity encoder implementations of QC-LDPC codes.Simulation results show that the QC-LDPC codes with large girth lifted from the constructed base matrices have good performances and outperform random codes,progressive edge growth LDPC codes,some finite fields and group rings based QC-LDPC codes and also have a close competition to the standard IEEE 802.16e(WiMAX)code.展开更多
Color inconsistency between views is an important problem to be solved in multi-view video applications, such as free viewpoint television and other three-dimensional video systems. In this paper, by combining with mu...Color inconsistency between views is an important problem to be solved in multi-view video applications, such as free viewpoint television and other three-dimensional video systems. In this paper, by combining with multi-view video coding, a coding-oriented multi-view video color correction method is proposed. We first separate foreground and background in first Group Of Pictures （GOP） by using SKIP coding mode. Then by transferring means and standard deviations in backgrounds, color correction is performed for each frame in GOP, and multi-view video coding is performed and used to renew the backgrounds. Experimental results ances in color correction and multi-view video show the proposed method can obtain better performcoding.展开更多
The desert plant Rhazya stricta has anticancer and antimicrobial properties, and is widely used in indigenous medicines of Saudi Arabia. However, the therapeutic benefits rely on an accurate identification of this spe...The desert plant Rhazya stricta has anticancer and antimicrobial properties, and is widely used in indigenous medicines of Saudi Arabia. However, the therapeutic benefits rely on an accurate identification of this species. The authenticity of R. stricta and other medicinal plants and herbs procured from local markets can be questionable due to a lack of clear phenotypic traits. DNA barcoding is an emerging technology for rapid and accurate species identification. In this study, six candidate chloroplastid barcodes were investigated for the authentication of R. stricta. We compared the DNA sequences from fifty locally collected and five market samples of R. stricta with database sequences of R. stricta and seven closely related species. We found that the coding regions matK, rbcL, rpoB, and rpoC1 were highly similar among the taxa. By contrast, the intergenic spacers psbK-psbI and atpF-atpH were variable loci distinct for the medicinal plant R. stricta. psbK-psbI clearly discriminated R. stricta samples as an efficient single locus marker, whereas a two-locus marker combination comprising psbK-psbI + atpF-atpH was also promising according to results from the Basic Local Alignment Search Tool and a maximum likelihood gene tree generated using PHyML. Two-dimensional DNA barcodes (i.e., QR codes) for the psbK-psbI and psbK-psbI + atpF-atpH regions were created for the validation of fresh or dried R. stricta samples.展开更多
This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping ...This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping method is applied to image correction, the final steps of decoding are given. The actual test results show that, the design algorithm has theoretical and practical, this recognition system can correctly read QR code, and has high recognition rate and recognition speed, has practical value and application prospect.展开更多
Objective: to explore the diagnostic value of four-dimensional color ultrasound screening for fetal congenital heart disease. Methods: 152 patients who were screened in our hospital from January 2017 to January 2020 w...Objective: to explore the diagnostic value of four-dimensional color ultrasound screening for fetal congenital heart disease. Methods: 152 patients who were screened in our hospital from January 2017 to January 2020 were selected as the subjects. All patients were examined by four-dimensional color ultrasound and two-dimensional color ultrasound. The diagnostic value of fetal congenital heart disease screening with four-dimensional color ultrasound was judged. Results: the detection rate of four-dimensional color ultrasound was 13.82%, and the coincidence rate with pathological diagnosis was 90.48%. The detection rate of two-dimensional color ultrasound was 11.84% and the diagnostic accuracy was 83.33%. The results showed that the accuracy of four-dimensional color ultrasound in the diagnosis of congenital heart disease was higher than that of two-dimensional color ultrasound. The difference was statistically significant. Conclusion: fetal congenital heart disease screening with four-dimensional color Doppler ultrasound has high accuracy, which is of great significance to fetal prenatal examination and can be popularized and applied in clinic.展开更多
基金the National Key R&D Program of China(2021YFA1401200)Beijing Outstanding Young Scientist Program(BJJWZYJH01201910007022)+2 种基金National Natural Science Foundation of China(No.U21A20140,No.92050117)Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(No.Z211100004821009)X.Li acknowledges the support from Beijing Institute of Technology Research Fund Program for Young Scholars(XSQD-201904005).
文摘Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface holography can only realize static manipulation.In this study,we propose and demonstrate a multiplexing metasurface technique combined with multiwavelength code-division multiplexing(CDM)to realize dynamic manipulation.Multicolor code references are utilized to record information within a single metasurface and increase the information capacity and security for anticracks.A total of 48 monochrome images consisting of pure color characters and multilevel color video frames were reconstructed in dual polarization channels of the birefringent metasurface to exhibit high information density,and a video was displayed via sequential illumination of the corresponding code patterns to verify the ability of dynamic manipulation.Our approach demonstrates significant application potential in optical data storage,optical encryption,multiwavelengthversatile diffractive optical elements,and stimulated emission depletion microscopy.
基金Supported by the National Natural Science Foundation of China(61071221,10831002)
文摘Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62001249 and 61871234)the NUPTSF(Grant No.NY220004)the Scientific Research Project of College of Information Engineering,Fuyang Normal University(Grant No.FXG2021ZZ02)。
文摘We propose a new full color ghost imaging scheme using both time and code division multiplexing technologies.In the scheme,the speckle patterns of three colors(red,green and blue)are modulated with different time slots and codes.The light intensity is sampled by one bucket detector.Then based on the modulated time slots and codes,we can effectively and simultaneously extract three detection component signals corresponding to three color components of objects from the sampling signal of the bucket detector.Finally,three component images resulting from the three component detection signals can be synthesized into a full color image.The experimental results verify the feasibility of our scheme under the limit of the number of time slots and codes.Moreover,our scheme reduces the number of bucket detectors and can realize high quality imaging even in a noisy environment.
文摘In this paper,hyperbolic geometry is used to constructing new quantum color codes.We use hyperbolic tessellations and hyperbolic polygons to obtain them by pairing the edges on compact surfaces.These codes have minimum distance of at least 4 and the encoding rate near to 1,which are not mentioned in other literature.Finally,a comparison table with quantum codes recently proposed by the authors is provided.
基金Supported by the Eleventh Five-Year Pre-research Project of China.
文摘A new 3D surface contouring and ranging system based on digital fringe projection and phase shifting technique is presented. Using the phase-shift technique, points cloud with high spatial resolution and limited accuracy can be generated. Stereo-pair images obtained from two cameras can be used to compute 3D world coordinates of a point using traditional active triangulation approach, yet the camera calibration is crucial. Neural network is a well-known approach to approximate a nonlinear system without an explicit physical model, in this work it is used to train the stereo vision application system to calculating 3D world coordinates such that the camera calibration can be bypassed. The training set for neural network consists of a variety of stereo-pair images and the corresponding 3D world coordinates. The picture elements correspondence problem is solved by using projected color-coded fringes with different orientations. Color imbalance is completely eliminated by the new color-coded method. Once the high accuracy correspondence of 2D images with 3D points is acquired, high precision 3D points cloud can be recognized by the well trained net. The obvious advantage of this approach is that high spatial resolution can be obtained by the phase-shifting technique and high accuracy 3D object point coordinates are achieved by the well trained net which is independent of the camera model works for any type of camera. Some experiments verified the performance of the method.
基金supported by the National Natural Science Foundation of China(Grant Nos.62375137 and 62175114).
文摘Structural colors based on metasurfaces have very promising applications in areas such as optical image encryption and color printing.Herein,we propose a deep learning-enabled reverse design of polarization-selective structural color based on coding metasurface.In this study,the long short-term memory(LSTM)neural network is presented to enable the forward and inverse mapping between coding metasurface structure and corresponding color.The results show that the method can achieve 98%accuracy for the forward prediction of color and 93%accuracy for the inverse design of the structure.Moreover,a cascaded architecture is adopted to train the inverse neural network model,which can solve the nonuniqueness problem of the polarization-selective color reverse design.This study provides a new path for the application and development of structural colors.
文摘he objective of the research is to develop a fast procedure for segmenting typical videophone images. In this paper, a new approach to color image segmentation based on HSI(Hue, Saturation, Intensity) color model is reported. It is in contrast to the conventional approaches by using the three components of HSI color model in succession. This strategy makes the segmentation procedure much fast and effective. Experimental results with typical “headandshoulders” real images taken from videophone sequences show that the new appproach can fulfill the application requirements.
基金Supported by Scientific Industry and Development Foundation of Institute of Automation,Chinese Academy of Sciences(DC07J03)
文摘In this paper,we propose a novel pseudo-color approach which can effectively mark all different particulars while it has the ability to divide foreign pieces with indiscernible brightness in fibre masses.Hence,it yields highly separate color images for this kind of industrial images.Our approach aims at constructing an adaptive fuzzy rule based on a feature space of gradients,gray values,local entropies,and local features from scalable morphological filters.Due to the fact that the method is based on a full contextual information,it can handle small changes in images more adaptively than classical pseudo-color methods.And it is perfectly suitable to distinguish impurities mixed in fibre masses,as tested in a simulating cotton inspection system and demonstrated by several cotton sample images.
基金Sponsored by the Opening Project of National Key Laboratory of Science and Technology on Reliability PhysicsApplication Technology of Electrical Component(Grant No.ZHD200903)
文摘This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62105004 and 52174141)the College Student Innovation and Entrepreneurship Fund Project(Grant No.202210361053)+1 种基金Anhui Mining Machinery and Electrical Equipment Coordination Innovation Center,Anhui University of Science&Technology(Grant No.KSJD202304)the Anhui Province Digital Agricultural Engineering Technology Research Center Open Project(Grant No.AHSZNYGC-ZXKF021)。
文摘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.
基金Project supported by the National Natural Science Foundation of China (No. 60772134)the Innovation Foundation of Xidian University,China (No. Chuang 05018)
文摘A novel color compensation method for multi-view video coding (MVC) is proposed, which efficiently exploits the inter-view dependencies between views with the existence of color mismatch caused by the diversity of cameras. A color compensation model is developed in RGB channels and then extended to YCbCr channels for practical use. A modified inter-view reference picture is constructed based on the color compensation model, which is more similar to the coding picture than the original inter-view reference picture. Moreover, the color compensation factors can be derived in both encoder and decoder, therefore no additional data need to be transmitted to the decoder. The experimental results show that the proposed method improves the coding efficiency of MVC and maintains good subjective quality.
基金supported by the National High-Technology Research and Development Program of China （Grant No.2003AA123310）, and the National Natural Science Foundation of China （Grant Nos.60332030, 60572157）
文摘In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural order in storage, our scheme requires 25 more memory blocks but allows a simpler configuration for variable sizes of code lengths that can be implemented on-chip. Experiment shows that for a moderate to high decoding throughput （40-100 Mbps）, the hardware cost is still affordable for 3GPP＇s （3rd generation partnership project） interleaver.
基金The authors would like to thank anonymous referees for their valuable comments enabled us to greatly improve the quality of the paper.The research of the first author is partially supported by Shahrekord University grant No.97GRN1M1465.
文摘In this paper,a new type of edge coloring of graphs together with an algorithm for such an edge coloring is presented to construct some columnweight three low-density parity-check(LDPC)codes whose Tanner graphs are free of 4-cycles.This kind of edge coloring is applied on some well-known classes of graphs such as complete graphs and complete bipartite graphs to generate some column-weight 3 LDPC codes having flexibility in terms of code length and rate.Interestingly,the constructed(3;k)-regular codes with regularities k=4;5;:::;22 have lengths n=12;20;26,35;48;57;70;88;104;117;140;155;176;204;228;247;280;301;330;having minimum block length compared to the best known similar codes in the literature.In addition to linear complexity of generating such parity-check matrices,they can be considered as the base matrices of some quasi-cyclic(QC)LDPC codes with maximum achievable girth 18,which inherit the low-complexity encoder implementations of QC-LDPC codes.Simulation results show that the QC-LDPC codes with large girth lifted from the constructed base matrices have good performances and outperform random codes,progressive edge growth LDPC codes,some finite fields and group rings based QC-LDPC codes and also have a close competition to the standard IEEE 802.16e(WiMAX)code.
基金the National Natural Science Foundation of China (No.60672073, No.60872094)the Program for New Century Excellent Talents in University (NCET-06-0537)+2 种基金the Key Project of Chinese Ministry of Education (No. 206059)Scientific Research Fund of Zhejiang Provincial Education Department (No.20070962)the Natural Science Foundation of Ningbo (No.2008A610016).
文摘Color inconsistency between views is an important problem to be solved in multi-view video applications, such as free viewpoint television and other three-dimensional video systems. In this paper, by combining with multi-view video coding, a coding-oriented multi-view video color correction method is proposed. We first separate foreground and background in first Group Of Pictures （GOP） by using SKIP coding mode. Then by transferring means and standard deviations in backgrounds, color correction is performed for each frame in GOP, and multi-view video coding is performed and used to renew the backgrounds. Experimental results ances in color correction and multi-view video show the proposed method can obtain better performcoding.
文摘The desert plant Rhazya stricta has anticancer and antimicrobial properties, and is widely used in indigenous medicines of Saudi Arabia. However, the therapeutic benefits rely on an accurate identification of this species. The authenticity of R. stricta and other medicinal plants and herbs procured from local markets can be questionable due to a lack of clear phenotypic traits. DNA barcoding is an emerging technology for rapid and accurate species identification. In this study, six candidate chloroplastid barcodes were investigated for the authentication of R. stricta. We compared the DNA sequences from fifty locally collected and five market samples of R. stricta with database sequences of R. stricta and seven closely related species. We found that the coding regions matK, rbcL, rpoB, and rpoC1 were highly similar among the taxa. By contrast, the intergenic spacers psbK-psbI and atpF-atpH were variable loci distinct for the medicinal plant R. stricta. psbK-psbI clearly discriminated R. stricta samples as an efficient single locus marker, whereas a two-locus marker combination comprising psbK-psbI + atpF-atpH was also promising according to results from the Basic Local Alignment Search Tool and a maximum likelihood gene tree generated using PHyML. Two-dimensional DNA barcodes (i.e., QR codes) for the psbK-psbI and psbK-psbI + atpF-atpH regions were created for the validation of fresh or dried R. stricta samples.
文摘This paper briefly introduces the characteristics and structure of symbol QR two-dimensional code, a detailed analysis of the image processing method to identify QR code of the whole process, and the bilinear mapping method is applied to image correction, the final steps of decoding are given. The actual test results show that, the design algorithm has theoretical and practical, this recognition system can correctly read QR code, and has high recognition rate and recognition speed, has practical value and application prospect.
文摘Objective: to explore the diagnostic value of four-dimensional color ultrasound screening for fetal congenital heart disease. Methods: 152 patients who were screened in our hospital from January 2017 to January 2020 were selected as the subjects. All patients were examined by four-dimensional color ultrasound and two-dimensional color ultrasound. The diagnostic value of fetal congenital heart disease screening with four-dimensional color ultrasound was judged. Results: the detection rate of four-dimensional color ultrasound was 13.82%, and the coincidence rate with pathological diagnosis was 90.48%. The detection rate of two-dimensional color ultrasound was 11.84% and the diagnostic accuracy was 83.33%. The results showed that the accuracy of four-dimensional color ultrasound in the diagnosis of congenital heart disease was higher than that of two-dimensional color ultrasound. The difference was statistically significant. Conclusion: fetal congenital heart disease screening with four-dimensional color Doppler ultrasound has high accuracy, which is of great significance to fetal prenatal examination and can be popularized and applied in clinic.
