针对透明物体逆光图像对比度低、可视质量差、部分区域过度曝光、边缘信息模糊等问题,提出了一种改进MSRCR(Multi-Scale Retinex with Color Restoration)的透明物体逆光图像增强算法。首先,在MSRCR算法的基础上添加最小可觉差的倒数作...针对透明物体逆光图像对比度低、可视质量差、部分区域过度曝光、边缘信息模糊等问题,提出了一种改进MSRCR(Multi-Scale Retinex with Color Restoration)的透明物体逆光图像增强算法。首先,在MSRCR算法的基础上添加最小可觉差的倒数作为光照分量的调节因子,解决图像的色偏问题,得到准确清晰的透明物体边缘信息;然后,利用自适应对比度增强算法对原图像进行处理,得到亮度适中,对比度高的图像;最后,将两幅图像按亮度均值比例进行拉普拉斯金字塔融合,并进行线性拉伸。将该算法应用于安瓿瓶视觉尺寸测量,结果表明:改进MSRCR的透明物体逆光图像增强算法,能有效解决MSRCR算法的色偏问题,突显透明物体边缘细节信息,并保留亮度增强效果,将安瓿瓶的尺寸误差由0.35 mm降低到0.1mm,提高了透明物体尺寸测量精度。展开更多
Two 50-μm Mo wires in parallel used as a Z-pinch load are electrically exploded with a pulsed current rising to 275 kA in 125 ns and their explosion processes are backlighted using an X-pinch as an x-ray source. The ...Two 50-μm Mo wires in parallel used as a Z-pinch load are electrically exploded with a pulsed current rising to 275 kA in 125 ns and their explosion processes are backlighted using an X-pinch as an x-ray source. The backlighting images show clearly the processes similar to those occurring in the initial stages of a cylindrical wire-array Z-pinch, including the electric explosion of single wires characterised by the dense wire cores surrounded by a low-density coronal plasma, the expansion of the exploding wire, the sausage instability （m = 0） in the coronal plasma around each wire, the motion of the coronal plasma as well as the wire core toward the current centroid, the formation of the precursor plasma column with a twist structure something like that of higher mode instability, especially the kink instability （m = 1）.展开更多
In order to acquire the most energy-saving luminairedistribution-parameters(LDPs)of highway tunnel interior zone backlighting,the parameters optimization model(POM)of backlighting for tunnel interior zone was establis...In order to acquire the most energy-saving luminairedistribution-parameters(LDPs)of highway tunnel interior zone backlighting,the parameters optimization model(POM)of backlighting for tunnel interior zone was established.Yanlieshan tunnel of Jiujing highway was taken as an example for the optimization.The optimal LDPs of the backlighting system of the tunnel interior zone were obtained by the POM,a comparison between the optimization results and those of Yanlieshan tunnel’s actual lighting system was performed,which showed that the optimized backlighting system with LED lamps installed according to the optimized LDPs could save energy remarkablely even under full capacity lighting condition.Illuminance and illuminance uniformity of the tunnel road surface still met the lighting demands even the LED lamp’s luminance decreased by 30%.A backlighting simulation experiment with the optimized backlighting LDPs for Yanlieshan tunnel was accomplished in the software Dialux.The simulation results basically agreed with the optimization calculated results from the POM which proved the correctness of the backlighting POM.展开更多
A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strateg...A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strategy, and the eye-tracking system, this spatial-sequential solution enables our autostereoscopic display to combine all the advantages of full resolution,wide color gamut, low crosstalk, and switchable 2D/3D. And also, we fabricated an autostereoscopic display prototype and demonstrated its performances effectively. The results indicate that our system can both break the limitation of viewing position and provide high-quality 3D images. We present two working modes in this system. In the spatial-sequential mode,the crosstalk is about 6%. In the time-multiplexed mode, the viewer should wear auxiliary and the crosstalk is about 1%,just next to that of a commercial 3D display(BENQ XL2707-B and View Sonic VX2268 WM). Additionally, our system is also completely compatible with active shutter glasses and its 3D resolution is same as its 2D resolution. Because of the excellent properties of the QD material, the color gamut can be widely extended to 77.98% according to the ITU-R recommendation BT.2020(Rec.2020).展开更多
An X-pinch axial backlighting system has been designed to quantitatively measure the density distribution of wirearray Z-pinch plasmas. End-on backlighting experiments were carried out on a 200 kA, 100 ns pulsed-power...An X-pinch axial backlighting system has been designed to quantitatively measure the density distribution of wirearray Z-pinch plasmas. End-on backlighting experiments were carried out on a 200 kA, 100 ns pulsed-power generator（PPG-1） at the Tsinghua University. Compared with side-on backlighting, end-on measurements provide an axial view of the evolution of Z-pinch plasmas. Early stages of 2-, 4-, and 8-wire Z-pinch plasmas were observed via point-projection backlighting radiography with a relatively high success rate. The density distribution of Z-pinch plasma on the r–θ plane was obtained directly from the images with the help of step wedges, and the inward radial velocity was calculated. The ablation rates obtained by X-pinch backlighting experiments are compared in detail with those calculated by the rocket model and the results show consistency.展开更多
This study proposes an innovative design method for functional optical film microstructures used in displays and applies this design to LCD backlighting to replace multi-layer optical film functional integration with ...This study proposes an innovative design method for functional optical film microstructures used in displays and applies this design to LCD backlighting to replace multi-layer optical film functional integration with composite optical film. We design a novel optical film microstructure based on light uniformity and wide-angle lumination distribution and determine the optimal optical microstructure parameters by combining the global optimization of a genetic algorithm with ray tracing. The purpose of this study is to develop substitutes for traditional multi-layer prism brightness enhancers and light-diffusing film stacks and to examine the structural changes during calculations and summarize the characteristics. In this study, we focus on determining the optimal light uniformity of new optical film microstructures. The seven-inch LED backlight module of the method proposed in this study achieved 94.59% uniformity and 168° lumination distribution while reducing thickness by 66% to 82% compared to a traditional multi-layer optical film stack.展开更多
We utilized "direct illumination-type" LED backlight project, made white-light LED array in rectangle, designed a sheet of reflective film, a sheet of diffuser and two sheets of brightness enhancement film, ...We utilized "direct illumination-type" LED backlight project, made white-light LED array in rectangle, designed a sheet of reflective film, a sheet of diffuser and two sheets of brightness enhancement film, then analyzed illuminance chart which was the result of simulation in several distance between reflective film and optical film. It showed the best matching between illuminance and uniformity while in 25mm distance. Finally, we discussed some problems with thermal dispersion.展开更多
文摘针对透明物体逆光图像对比度低、可视质量差、部分区域过度曝光、边缘信息模糊等问题,提出了一种改进MSRCR(Multi-Scale Retinex with Color Restoration)的透明物体逆光图像增强算法。首先,在MSRCR算法的基础上添加最小可觉差的倒数作为光照分量的调节因子,解决图像的色偏问题,得到准确清晰的透明物体边缘信息;然后,利用自适应对比度增强算法对原图像进行处理,得到亮度适中,对比度高的图像;最后,将两幅图像按亮度均值比例进行拉普拉斯金字塔融合,并进行线性拉伸。将该算法应用于安瓿瓶视觉尺寸测量,结果表明:改进MSRCR的透明物体逆光图像增强算法,能有效解决MSRCR算法的色偏问题,突显透明物体边缘细节信息,并保留亮度增强效果,将安瓿瓶的尺寸误差由0.35 mm降低到0.1mm,提高了透明物体尺寸测量精度。
基金supported by the National Natural Science Foundation of China (Grant No. 10635050)the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No. 200748)+2 种基金the International Atomic Energy Agency (Grant No. 14509)the Postdoctoral Science Foundation of China (Grant No. 20090450355)the Special Research Fund for the Doctoral Program of Higher Education,China (Grant No. 200800030037)
文摘Two 50-μm Mo wires in parallel used as a Z-pinch load are electrically exploded with a pulsed current rising to 275 kA in 125 ns and their explosion processes are backlighted using an X-pinch as an x-ray source. The backlighting images show clearly the processes similar to those occurring in the initial stages of a cylindrical wire-array Z-pinch, including the electric explosion of single wires characterised by the dense wire cores surrounded by a low-density coronal plasma, the expansion of the exploding wire, the sausage instability （m = 0） in the coronal plasma around each wire, the motion of the coronal plasma as well as the wire core toward the current centroid, the formation of the precursor plasma column with a twist structure something like that of higher mode instability, especially the kink instability （m = 1）.
基金National Natural Science Foundation of China(No.61463015)
文摘In order to acquire the most energy-saving luminairedistribution-parameters(LDPs)of highway tunnel interior zone backlighting,the parameters optimization model(POM)of backlighting for tunnel interior zone was established.Yanlieshan tunnel of Jiujing highway was taken as an example for the optimization.The optimal LDPs of the backlighting system of the tunnel interior zone were obtained by the POM,a comparison between the optimization results and those of Yanlieshan tunnel’s actual lighting system was performed,which showed that the optimized backlighting system with LED lamps installed according to the optimized LDPs could save energy remarkablely even under full capacity lighting condition.Illuminance and illuminance uniformity of the tunnel road surface still met the lighting demands even the LED lamp’s luminance decreased by 30%.A backlighting simulation experiment with the optimized backlighting LDPs for Yanlieshan tunnel was accomplished in the software Dialux.The simulation results basically agreed with the optimization calculated results from the POM which proved the correctness of the backlighting POM.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFB0401503)the R&D Plan of Jiangsu Science and Technology Department,China(Grant No.BE2016173)
文摘A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strategy, and the eye-tracking system, this spatial-sequential solution enables our autostereoscopic display to combine all the advantages of full resolution,wide color gamut, low crosstalk, and switchable 2D/3D. And also, we fabricated an autostereoscopic display prototype and demonstrated its performances effectively. The results indicate that our system can both break the limitation of viewing position and provide high-quality 3D images. We present two working modes in this system. In the spatial-sequential mode,the crosstalk is about 6%. In the time-multiplexed mode, the viewer should wear auxiliary and the crosstalk is about 1%,just next to that of a commercial 3D display(BENQ XL2707-B and View Sonic VX2268 WM). Additionally, our system is also completely compatible with active shutter glasses and its 3D resolution is same as its 2D resolution. Because of the excellent properties of the QD material, the color gamut can be widely extended to 77.98% according to the ITU-R recommendation BT.2020(Rec.2020).
基金supported by the National Natural Science Foundation of China(Grant Nos.11177086 and 51177086)Guangdong Innovative Research Team Program of China(Grant No.2011S013)+2 种基金the National Key Research and Develop Program of China(Grant No.2016YFC0105102)the National Basic Research Program of China(Grant Nos.2012AA02A604 and 2015AA043203)Beijing Center for Mathematics and Information Interdisciplinary Sciences,China
文摘An X-pinch axial backlighting system has been designed to quantitatively measure the density distribution of wirearray Z-pinch plasmas. End-on backlighting experiments were carried out on a 200 kA, 100 ns pulsed-power generator（PPG-1） at the Tsinghua University. Compared with side-on backlighting, end-on measurements provide an axial view of the evolution of Z-pinch plasmas. Early stages of 2-, 4-, and 8-wire Z-pinch plasmas were observed via point-projection backlighting radiography with a relatively high success rate. The density distribution of Z-pinch plasma on the r–θ plane was obtained directly from the images with the help of step wedges, and the inward radial velocity was calculated. The ablation rates obtained by X-pinch backlighting experiments are compared in detail with those calculated by the rocket model and the results show consistency.
文摘This study proposes an innovative design method for functional optical film microstructures used in displays and applies this design to LCD backlighting to replace multi-layer optical film functional integration with composite optical film. We design a novel optical film microstructure based on light uniformity and wide-angle lumination distribution and determine the optimal optical microstructure parameters by combining the global optimization of a genetic algorithm with ray tracing. The purpose of this study is to develop substitutes for traditional multi-layer prism brightness enhancers and light-diffusing film stacks and to examine the structural changes during calculations and summarize the characteristics. In this study, we focus on determining the optimal light uniformity of new optical film microstructures. The seven-inch LED backlight module of the method proposed in this study achieved 94.59% uniformity and 168° lumination distribution while reducing thickness by 66% to 82% compared to a traditional multi-layer optical film stack.
文摘We utilized "direct illumination-type" LED backlight project, made white-light LED array in rectangle, designed a sheet of reflective film, a sheet of diffuser and two sheets of brightness enhancement film, then analyzed illuminance chart which was the result of simulation in several distance between reflective film and optical film. It showed the best matching between illuminance and uniformity while in 25mm distance. Finally, we discussed some problems with thermal dispersion.
