Pub Date : 2014-01-01DOI: 10.3788/GXJS20144003.0258
付毅 Fu Yi, 吴泽民 Wu Zemin, 田畅 Tian Chang, 曾明勇 Zeng Mingyong, 揭斐然 Jie Feiran
Scene classification is a hot topic in computer vision.Under the premise of image segmentation,a novel scene classification algorithm is proposed,which combines pixel location,color characteristics,direction features and local texture features to form the covariance descriptor.To avoid computing tedious distance measure in Riemannian space,the covariance descriptor is converted into sigma-point representation,where scene describing and SVM based training can be completed in Euclidian space.The performance of the novel algorithm is compared with some of classical algorithms using SUN Database.Farther more,the robustness of the algorithm is validated with noise appended data samples.The results show that the proposed algorithm not only has advantages on computation time and classification performance,but also has good robustness to scene noise.
{"title":"A algorithm for scene classification based on covariance descriptor","authors":"付毅 Fu Yi, 吴泽民 Wu Zemin, 田畅 Tian Chang, 曾明勇 Zeng Mingyong, 揭斐然 Jie Feiran","doi":"10.3788/GXJS20144003.0258","DOIUrl":"https://doi.org/10.3788/GXJS20144003.0258","url":null,"abstract":"Scene classification is a hot topic in computer vision.Under the premise of image segmentation,a novel scene classification algorithm is proposed,which combines pixel location,color characteristics,direction features and local texture features to form the covariance descriptor.To avoid computing tedious distance measure in Riemannian space,the covariance descriptor is converted into sigma-point representation,where scene describing and SVM based training can be completed in Euclidian space.The performance of the novel algorithm is compared with some of classical algorithms using SUN Database.Farther more,the robustness of the algorithm is validated with noise appended data samples.The results show that the proposed algorithm not only has advantages on computation time and classification performance,but also has good robustness to scene noise.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"258-264"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70264598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144003.0286
刘树民 Liu Shumin
A method for measuring cube right angle errors with planar interferometer is introduced.Laser interferometer measurement method has high precision and high sensitivity.A cube bearing fixture is fabricated to ensure the measuring light can outgo from the incident plane after reflection in the cube.When the outgoing light coincides with parallel measuring light,interference is formed and cube right angle errorsΔ90°are measured with planar interferometer.Meanwhile,indicators such as surface flatness of the cube and defects in the glass can also be judged at the same time.The method equates to prism lens interferometer in the cube right angle errors measuring.
{"title":"Detection method for the cube right angle errors with plane interferometer","authors":"刘树民 Liu Shumin","doi":"10.3788/GXJS20144003.0286","DOIUrl":"https://doi.org/10.3788/GXJS20144003.0286","url":null,"abstract":"A method for measuring cube right angle errors with planar interferometer is introduced.Laser interferometer measurement method has high precision and high sensitivity.A cube bearing fixture is fabricated to ensure the measuring light can outgo from the incident plane after reflection in the cube.When the outgoing light coincides with parallel measuring light,interference is formed and cube right angle errorsΔ90°are measured with planar interferometer.Meanwhile,indicators such as surface flatness of the cube and defects in the glass can also be judged at the same time.The method equates to prism lens interferometer in the cube right angle errors measuring.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"286-288"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70264658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144004.0367
范志新 Fan Zhi-xin, 高攀 Gao Pan
The concepts of polymer dispersed liquid crystal、sheared liquid crystal、scattering polarizer and transmitting projection screen are introduced.The samples of sheared liquid crystal scattering polarizer glass are prepared.The sample consisted of tow piece of glass and a layer of polymer dispersed liquid crystal film is formed during the UV solidification process while the shear stress added.The polarizing photograph and the curves of polarizing light transmissivity and haze with angle of light axis are given.The experimental results show that it looks translucent and there is light axis.To combine the scattering polarizer glass with absorbing polarizer,a new kind of light tunable function window is given,and to combine the glass with 1LCD projector or 1LCOS projector,the transmitting projection screen is obtained with excellent imaged effect for rear projection display system.
{"title":"Preparation and application of sheared liquid crystal scattering polarizer glass","authors":"范志新 Fan Zhi-xin, 高攀 Gao Pan","doi":"10.3788/GXJS20144004.0367","DOIUrl":"https://doi.org/10.3788/GXJS20144004.0367","url":null,"abstract":"The concepts of polymer dispersed liquid crystal、sheared liquid crystal、scattering polarizer and transmitting projection screen are introduced.The samples of sheared liquid crystal scattering polarizer glass are prepared.The sample consisted of tow piece of glass and a layer of polymer dispersed liquid crystal film is formed during the UV solidification process while the shear stress added.The polarizing photograph and the curves of polarizing light transmissivity and haze with angle of light axis are given.The experimental results show that it looks translucent and there is light axis.To combine the scattering polarizer glass with absorbing polarizer,a new kind of light tunable function window is given,and to combine the glass with 1LCD projector or 1LCOS projector,the transmitting projection screen is obtained with excellent imaged effect for rear projection display system.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"367-370"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70265256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144004.0331
刘晓东 Liu Xiaodong, 李湘宁 Li Xiang-ning, 汪宇青 Wang Yuqing
Cyclorama light is a luminaire specialized in lighting cyclorama at a close distance.The light shall be have an asymmetric intensity distribution and cove a large angular area in order to obtain uniform illumination on a cyclorama in a specific area.Based on the geometrical optics and the theory of irradiance,the luminous intensity distribution that satisfies the uniform illumination is calculated first.The secondary optical design based on the optical properties of the LED is developed,so that emergent light intensity distribution of the LED cyclorama light can match the luminous intensity distribution curve model.According to the law of conservation of energy,the luminous intensity distribution curve is equivalently divided in a discrete manner,and then effective superposition and compensation of directive rays and reflective rays are built.The reflective surface is designed according to the said method to realize the lighting requirements.The simulation of the designed LED cyclorama light by Zemax shows that cycloramas with different sizes and structure can be illuminated uniformly at a close distance through a simple lighting superposition of several designed LED cyclorama lights.The uniformity of illumination is above 85%and the energy efficiency is above 80%.
{"title":"Optical design of an LED cyclorama light","authors":"刘晓东 Liu Xiaodong, 李湘宁 Li Xiang-ning, 汪宇青 Wang Yuqing","doi":"10.3788/GXJS20144004.0331","DOIUrl":"https://doi.org/10.3788/GXJS20144004.0331","url":null,"abstract":"Cyclorama light is a luminaire specialized in lighting cyclorama at a close distance.The light shall be have an asymmetric intensity distribution and cove a large angular area in order to obtain uniform illumination on a cyclorama in a specific area.Based on the geometrical optics and the theory of irradiance,the luminous intensity distribution that satisfies the uniform illumination is calculated first.The secondary optical design based on the optical properties of the LED is developed,so that emergent light intensity distribution of the LED cyclorama light can match the luminous intensity distribution curve model.According to the law of conservation of energy,the luminous intensity distribution curve is equivalently divided in a discrete manner,and then effective superposition and compensation of directive rays and reflective rays are built.The reflective surface is designed according to the said method to realize the lighting requirements.The simulation of the designed LED cyclorama light by Zemax shows that cycloramas with different sizes and structure can be illuminated uniformly at a close distance through a simple lighting superposition of several designed LED cyclorama lights.The uniformity of illumination is above 85%and the energy efficiency is above 80%.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"331-334"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70265483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144005.0399
李佳琦 Li Jiaqi, 倪建明 Ni Jianming, 陈贵 Chen Gui, 刘文革 Liu Wenge, 田驰 Tian Chi, 李川 Li Chuan
The proportion of gob coal spontaneous is about 70% in mine fire.More than 50% of state-owned coalmine exist the danger of coal fire.So online monitoring of temperature is very important.A temperature sensor is used in the coal mine tunnel.The sensor principle is that temperature change is transited into fiber Bragg grating wavelength shift.According to Zhu Xian coal mine tunnel coal distribution and diffusion characteristics,at the top of coal mine tunnel,every 2mlong,intrinsically safe distributed fiber Bragg grating temperature sensors are installed along the roadway direction.A real-time temperature monitoring of the area is achieved.
{"title":"Gob coal mine tunnel temperature changes caused by spontaneous combustion of coal online monitoring","authors":"李佳琦 Li Jiaqi, 倪建明 Ni Jianming, 陈贵 Chen Gui, 刘文革 Liu Wenge, 田驰 Tian Chi, 李川 Li Chuan","doi":"10.3788/GXJS20144005.0399","DOIUrl":"https://doi.org/10.3788/GXJS20144005.0399","url":null,"abstract":"The proportion of gob coal spontaneous is about 70% in mine fire.More than 50% of state-owned coalmine exist the danger of coal fire.So online monitoring of temperature is very important.A temperature sensor is used in the coal mine tunnel.The sensor principle is that temperature change is transited into fiber Bragg grating wavelength shift.According to Zhu Xian coal mine tunnel coal distribution and diffusion characteristics,at the top of coal mine tunnel,every 2mlong,intrinsically safe distributed fiber Bragg grating temperature sensors are installed along the roadway direction.A real-time temperature monitoring of the area is achieved.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"399-401"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70265667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144005.0454
柳翔 Liu Xiang, 励强华 Li Qianghua
The characteristics of long period fiber grating transmission in uniform temperature field and non-uniform temperature fields is theoretically analyzed.The spectrum characteristics of long period fiber grating transmission in uniform temperature field and non-uniform temperature field with experiments are demonstrated.Experiments prove that with the rise of temperature,the synchronous wave center of fiber grating drifts to the long wave direction,the reverse is also the true,and drift distance has linear relations with the variation of temperature.In non-uniform temperature filed,when the temperature difference on both grating ends of long period fiber grating changes,the 3dB spread of synchronous waves show the linear increasing trend.
{"title":"Research on long period fiber grating transmission spectrum in uniform and non-uniform temperature fields","authors":"柳翔 Liu Xiang, 励强华 Li Qianghua","doi":"10.3788/GXJS20144005.0454","DOIUrl":"https://doi.org/10.3788/GXJS20144005.0454","url":null,"abstract":"The characteristics of long period fiber grating transmission in uniform temperature field and non-uniform temperature fields is theoretically analyzed.The spectrum characteristics of long period fiber grating transmission in uniform temperature field and non-uniform temperature field with experiments are demonstrated.Experiments prove that with the rise of temperature,the synchronous wave center of fiber grating drifts to the long wave direction,the reverse is also the true,and drift distance has linear relations with the variation of temperature.In non-uniform temperature filed,when the temperature difference on both grating ends of long period fiber grating changes,the 3dB spread of synchronous waves show the linear increasing trend.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"148 1","pages":"454-458"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70266226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144006.0565
刘. L. Yan, 李腾飞 Li Tengfei
A new two stage camera calibration based on Zhang Zhengyou method is proposed to solve the distortion of fish eye lens.Initial parameters are solved as a closed form solution,which are further refined by using non linear least square method,the extrinsic and intrinsic parameters are got,the robustness of initial value can be improved and the tangential distortion is taken into considertion.The proposed method compares with the Zhang's method converges fast and has anaccuracy of 1.2σ.
{"title":"Reaserch of the improvement of Zhang's camera calibration method","authors":"刘. L. Yan, 李腾飞 Li Tengfei","doi":"10.3788/GXJS20144006.0565","DOIUrl":"https://doi.org/10.3788/GXJS20144006.0565","url":null,"abstract":"A new two stage camera calibration based on Zhang Zhengyou method is proposed to solve the distortion of fish eye lens.Initial parameters are solved as a closed form solution,which are further refined by using non linear least square method,the extrinsic and intrinsic parameters are got,the robustness of initial value can be improved and the tangential distortion is taken into considertion.The proposed method compares with the Zhang's method converges fast and has anaccuracy of 1.2σ.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"565-570"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70266532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144001.0007
林政宗 Lin Zhengzong, 吕科 Lv Ke, 杨. Y. Lei, 徐文 Xu Wen, 翟锐 Zhai Rui
Meteorological satellite is using landmarks in remote sensing images for automatic navigation.Coastline detection is an important step in the process.Through matching the detection result with the corresponding region of global standard landmark library,the offset is obtained to adjust the posture of satellite.Considering the characteristics of meteorological satellite image navigation process,a new method is proposed to detect coastline in the infrared channel.Cloud detection is made first,and a C-V model which is initialized by information in standard landmark library is used to promote the evolution of the curve.Experimental results show that the method fits meteorological infrared channel well and has advantages in efficiency,stability and accuracy.
{"title":"Coastline detection in remote sensing image of geostationary satellite","authors":"林政宗 Lin Zhengzong, 吕科 Lv Ke, 杨. Y. Lei, 徐文 Xu Wen, 翟锐 Zhai Rui","doi":"10.3788/GXJS20144001.0007","DOIUrl":"https://doi.org/10.3788/GXJS20144001.0007","url":null,"abstract":"Meteorological satellite is using landmarks in remote sensing images for automatic navigation.Coastline detection is an important step in the process.Through matching the detection result with the corresponding region of global standard landmark library,the offset is obtained to adjust the posture of satellite.Considering the characteristics of meteorological satellite image navigation process,a new method is proposed to detect coastline in the infrared channel.Cloud detection is made first,and a C-V model which is initialized by information in standard landmark library is used to promote the evolution of the curve.Experimental results show that the method fits meteorological infrared channel well and has advantages in efficiency,stability and accuracy.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"7-12"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70261886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144002.0113
李桂萍 Li Guiping, 周桃庚 Zhou Taogeng, 张继彦 Zhang Jiyan
The color is a common phenomenon in our society and life,and the existence of colors leads to color difference.Almost all walks of life have studied color difference,such as textile,printing,ceramics,building,digital display,image processing and so on.But so far,the study directly of threshold color difference of human eyes is very few.If wanting to research the color difference,firstly to produce colors which resulting in the color difference are needed.Recent studies have found that the sensitivity of human eyes distinguishing colors is more sensitive when using self-luminous color than using reflective color.An apparatus which can generate kinds of colors is designed by adjusting the color-mix machine which is placed between a small integrating sphere and a big integrating sphere.This can provide a precondition for measuring threshold color difference.
{"title":"An apparatus of producing colors for measuring threshold color difference of human visual","authors":"李桂萍 Li Guiping, 周桃庚 Zhou Taogeng, 张继彦 Zhang Jiyan","doi":"10.3788/GXJS20144002.0113","DOIUrl":"https://doi.org/10.3788/GXJS20144002.0113","url":null,"abstract":"The color is a common phenomenon in our society and life,and the existence of colors leads to color difference.Almost all walks of life have studied color difference,such as textile,printing,ceramics,building,digital display,image processing and so on.But so far,the study directly of threshold color difference of human eyes is very few.If wanting to research the color difference,firstly to produce colors which resulting in the color difference are needed.Recent studies have found that the sensitivity of human eyes distinguishing colors is more sensitive when using self-luminous color than using reflective color.An apparatus which can generate kinds of colors is designed by adjusting the color-mix machine which is placed between a small integrating sphere and a big integrating sphere.This can provide a precondition for measuring threshold color difference.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"113-117"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70262703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.3788/GXJS20144002.0118
孙. S. Ci, 巴音贺希格 Bayanheshig, 崔继承 Cui Ji-cheng, 唐玉国 Tang Yuguo
In order to determine spectral characteristics of the imaging spectrometer with convex grating,spectral calibration is required.A spectral calibration system of full field is designed which is based on the method of collimated monochromatic light.A spherical mirror is used to provide collimated light,and a freely sliding and rotating folding mirror is used to change the angle of incident light.The automation of the calibration system has been realized.The CODEV result of optical simulation proves the whole system is reliability.Analysis is done combined with structure and characteristics of the entire spectral calibration system.The result shows that the system spectral calibration's accuracy is better than 1%.The calibration system has many advantages such as small size,better commonality and so on.It may provide references for others.
{"title":"Design of full field and automatic spectral calibration system for imaging spectrometer with convex grating","authors":"孙. S. Ci, 巴音贺希格 Bayanheshig, 崔继承 Cui Ji-cheng, 唐玉国 Tang Yuguo","doi":"10.3788/GXJS20144002.0118","DOIUrl":"https://doi.org/10.3788/GXJS20144002.0118","url":null,"abstract":"In order to determine spectral characteristics of the imaging spectrometer with convex grating,spectral calibration is required.A spectral calibration system of full field is designed which is based on the method of collimated monochromatic light.A spherical mirror is used to provide collimated light,and a freely sliding and rotating folding mirror is used to change the angle of incident light.The automation of the calibration system has been realized.The CODEV result of optical simulation proves the whole system is reliability.Analysis is done combined with structure and characteristics of the entire spectral calibration system.The result shows that the system spectral calibration's accuracy is better than 1%.The calibration system has many advantages such as small size,better commonality and so on.It may provide references for others.","PeriodicalId":35591,"journal":{"name":"Guangxue Jishu/Optical Technique","volume":"40 1","pages":"118-122"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70262810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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