[ Objective] The aim of this study was to solve the problem of photographing small flowers and fruits with a common digital camera in field. [Method] Firstly, the photographic mode of a common digital camera was set ...[ Objective] The aim of this study was to solve the problem of photographing small flowers and fruits with a common digital camera in field. [Method] Firstly, the photographic mode of a common digital camera was set as ＂macro＂ （or ＂soft snap＂ ） and ＂flash off＂. Secondly, the small flower or fruit was magnified with a magnifying glass, and then the magnified flower or fruit was automatically focused with the digital camera lens. After automatic focusing, the shutter button was pressed and the photograph finished. [Result] With this method, the clear inflo- rescence or floral photographs of Eragrostis pilosa （ Gramineae ） , Bidens biternata （Compositae） and Tribulus terrester （Zygophllaceae） were obtained in field. [ Conclusion] The optical system of a digital camera has been changed by the magnifying glass, which improves the photographic function of a common digital camera to small flowers and fruits, and also easily gets their clear photographs.展开更多
The objective of this paper is to improve the monitoring speed and precision of fractional vegetation cover (fc). It mainly focuses on fc estimation when fcmax and fcmin are not approximately equal to 100% and 0%, res...The objective of this paper is to improve the monitoring speed and precision of fractional vegetation cover (fc). It mainly focuses on fc estimation when fcmax and fcmin are not approximately equal to 100% and 0%, respectively due to using remote sensing image with medium or low spatial resolution. Meanwhile, we present a new method of fc estimation based on a random set of fc maximum and minimum values from digital camera (DC) survey data and a di- midiate pixel model. The results show that this is a convenient, efficient and accurate method for fc monitoring, with the maximum error -0.172 and correlation coefficient of 0.974 between DC survey data and the estimated value of the remote sensing model. The remaining DC survey data can be used as verification data for the precision of the fc estimation. In general, the estimation of fc based on DC survey data and a remote sensing model is a brand-new development trend and deserves further extensive utilization.展开更多
Positioning of screw holes is an important production procedure for steel construction connecting with bolts.In this paper,a new production method is presented,in which the digital camera is used for taking pictures o...Positioning of screw holes is an important production procedure for steel construction connecting with bolts.In this paper,a new production method is presented,in which the digital camera is used for taking pictures of screw holes and other techniques are advanced.This paper also indicates that the pixels of CCD chip in photogrammetry should be chosen as all geometric units in an image,such as interior elements and all kinds of distortions.The measure can also simplify the camera calibration for determining the size of non-square pixel.展开更多
This work describes a calibration process for inexpensive consumer cameras integrated into a low cost and compact aerial multi-view imager for remote sensing and photogrammetry.The main advantage of this design is to ...This work describes a calibration process for inexpensive consumer cameras integrated into a low cost and compact aerial multi-view imager for remote sensing and photogrammetry.The main advantage of this design is to make the filming component lightweight and rapidly deployable,as well as reducing cost when compared with mainstream commercial oblique imagery.An in situ flight test was carried out in Guiyang.In that experiment,a meridian convergence-based approach was adopted to adjust preprocessing,the residue error and the captured images’exterior orientation linear and angular parameters were calculated by means of the direct geo-referencing approach yielding a favorable outcome for exterior orientation linear parameters of the camera,around 0.2–0.3 m deviation from the actual measured results at 1000 m flight above ground level.The camera’s exterior orientation angular parametersφ,ωwhose difference compared with the standard aerial aero triangulation approach reached a high accuracy level within the intended endurance of 0.005°.These results indicate that the compact implementation of the oblique aerial imager comprised of consumer level off-the-shelf digital cameras achieved competitive accuracy at a low cost and high versatility.展开更多
Objective This study aimed to evaluate the ability of a digital fundus camera to observe the development of the anterior chamber angle(ACA)in premature infants.Methods Forty-eight eyes of preterm infants(n=48)were exa...Objective This study aimed to evaluate the ability of a digital fundus camera to observe the development of the anterior chamber angle(ACA)in premature infants.Methods Forty-eight eyes of preterm infants(n=48)were examined by a digital fundus camera to observe the development of the ACA.ACA grading was performed based on the visualization of the anterior chamber structures according to the Scheie Angle Depth Evaluating System.Results ACA images from all 48 infants were successfully acquired using RetCam3.The corrected gestational age ranged from 30 weeks to 49 weeks,which covered the period from 2 months preterm to>2 months post-term.As the corrected gestational age increased,the corrected gestational age grading was significantly decreased.The mean corrected gestational ages of the infants corresponding to the ACA classification from grade IV to grade 0 were 32.75±1.89,37.20±1.30,39.75±2.38,40.56±2.24,and 44.23±2.14 weeks,respectively,which were all significantly different(P<0.05).The regression analysis showed a linear correlation between the grading of the ACA and the corrected gestational age(R2=0.724,P=0.0001).Conclusion The ACA of a full-term newborn can be fully detected and evaluated by a digital fundus camera.For premature infants,part of the ACA is not visible physiologically;however,it should not be misdiagnosed as angle closure or a narrow angle.展开更多
Frame rate is corresponding to the temporal resolution and the number of the pixels of the picture is corresponding to the spatial resolution. They are both very important for the researchers. The ideal image analysis...Frame rate is corresponding to the temporal resolution and the number of the pixels of the picture is corresponding to the spatial resolution. They are both very important for the researchers. The ideal image analysis and processing system should have high spatiotemporal characteristics, which is much expensive in practical use. A new method to enhance dynamic frame rate using multi-digital camera(DC) is proposed and the result shows that it could increase the frame rate effectively and decreases the cost in practical use.展开更多
A digital camera measuring system has been used successfully to measure the space fluctuation behaviors of Induced Dielectric Barrier Discharge (IDBD) plasma at atmospheric pres- sure. The experimental results showed ...A digital camera measuring system has been used successfully to measure the space fluctuation behaviors of Induced Dielectric Barrier Discharge (IDBD) plasma at atmospheric pres- sure. The experimental results showed that: (1) The uniformity of electron temperature in space depends on discharge condition and structure of web electrode. For a certain web electrode the higher the discharge voltage is, the more uniform distribution of electron temperature in space will be. For a certain discharge the finer and denser the holes on web electrode are, the more uniform distribution of electron temperature in space will be (2). Digital camera is an available equipment to measure some behaviors of the plasma working at atmospheric pressure.展开更多
用数码相机拍得的相片,在保存和网络传输方面有不容置疑的优越性,因此越来越多的人开始使用数码相机。但是我们不得不承认,它在成像质量方面还不能完全替代传统的相机。在你的数码像册里有没有一些太亮、太暗或者有杂点的问题照片呢?不...用数码相机拍得的相片,在保存和网络传输方面有不容置疑的优越性,因此越来越多的人开始使用数码相机。但是我们不得不承认,它在成像质量方面还不能完全替代传统的相机。在你的数码像册里有没有一些太亮、太暗或者有杂点的问题照片呢?不要以为它们没救了哦,看了今天介绍的方法你就会知道,其实要给它们做美容一点都不难,只要一分钟就可以让你的相片白净又明亮! 咱们要用的这一系列美容工具叫做:Digital camera Tools(本文介绍的软件都可在http://www.mediachance.com/digicam/下载),这些简单又实用的小工具基本上可以解决数码相片中存在的大部分常见问题,比如:偏色、亮度不正常、有杂点等,对传统相片中的类似问题也有一定的作用。每一种工具都有它的适用范围,如果你的照片不在其适用范围之内,或者原本就拍得不错的话,那你可能就看不到太大的差别哦!展开更多
ANDERS ANDERSSON_海外组一等奖我想一直想用无人机拍这样的自拍照片,于是邀请了我的邻居朋友Tobias在瑞典Ljungby的一个社区摆出这样的姿势。我们在泳池开放时间提前一个小时到达,大概半个小时后完成了拍摄。我也很想在泳池里人多的时...ANDERS ANDERSSON_海外组一等奖我想一直想用无人机拍这样的自拍照片,于是邀请了我的邻居朋友Tobias在瑞典Ljungby的一个社区摆出这样的姿势。我们在泳池开放时间提前一个小时到达,大概半个小时后完成了拍摄。我也很想在泳池里人多的时候拍,但是考虑到会有一定的危险就没有实行。"展开更多
Because single line-scan camera loses light in the edge of the sensor when the field of view is large, a mosaic cam- era based on field programmable gate array （FPGA） is presented by putting multiple cameras arrange...Because single line-scan camera loses light in the edge of the sensor when the field of view is large, a mosaic cam- era based on field programmable gate array （FPGA） is presented by putting multiple cameras arranged in a straight line to share the field of view and reduce the view angle of every camera. For detecting doping micro particles with the designed mosaic line-scan camera, a detection algorithm of the target＇s location in FPGA is proposed. Finally, the practicability and stability of the system were validated experimentally. The results of the experiment show that the camera can get images clearly with less light loss and can accurately distinguish the target and the background.展开更多
Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shr...Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shrub-grasses (G) separately in a subtropical forest area in Nanjing, China. Both upward and downward photographs were taken with a digital camera in 72 quadrats (10 m × 10 m each). Fifteen models were established and validated. Models jointly using both T and G performed better than those using the T and G separately. The best model, TG = T + G- 1.134 × T × G- 0.025 (R2 = 0.9115, P < 0.01, root mean squared error = 0.0789), is recommended for application. This model provides a good way to obtain total forest VFC values through taking tree and shrub-grass photos on ground below tree canopy rather than above tree canopy.展开更多
A difficult problem in forestry is tree inventory.In this study, a GoProHero attached to a small unmanned aerial vehicle was used to capture images of a small area covered by pinus pinea trees. Then, a digital surface...A difficult problem in forestry is tree inventory.In this study, a GoProHero attached to a small unmanned aerial vehicle was used to capture images of a small area covered by pinus pinea trees. Then, a digital surface model was generated with image matching. The elevation model representing the terrain surface, a ‘digital terrain model’,was extracted from the digital surface model using morphological filtering. Individual trees were extracted by analyzing elevation flow on the digital elevation model because the elevation reached the highest value on the tree peaks compared to the neighborhood elevation pixels. The quality of the results was assessed by comparison with reference data for correctness of the estimated number of trees. The tree heights were calculated and evaluated with ground truth dataset. The results showed 80% correctness and 90% completeness.展开更多
We develop a new technique to measure the exact upper diameters of trees that is comparatively simple and inexpensive. We can measure the diameters of entire tree trunks efficiently and with high precision. The system...We develop a new technique to measure the exact upper diameters of trees that is comparatively simple and inexpensive. We can measure the diameters of entire tree trunks efficiently and with high precision. The system uses a digital camera with a ~15 - 30× telephoto lens to take a photograph that can be used for measuring the diameter of the upper part of a comparatively slender tree trunk. Since this method requires a measuring distance and the height of the target point in the image, a range finder capable of measuring angles was combined with the main digiscoping system. A range finder sensor uses a laser and makes a 360 degree angle of observation possible. The diameter of a target position of the objective tree can be obtained by measuring the digital image using image editing software and calculations from spreadsheet software. We focus on the Japanese cedar species in the southwestern part of Japan. Photographic measurements were obtained prior to thinning. The estimates that we obtained largely agree with the true measurements of all trees. With regard to the estimated accuracy of all measured trees, the maximum error ratio was 7.0% (1.45 cm), with a ~2% - 4% error for most of the estimated results. Although the absolute value of the estimation error was 1.87 cm (5.3%) at the maximum (9.87 m in height and 35.5 cm in diameter), an estimation accuracy of <1 cm was reproduced in almost all measurements except for the extreme hypertrophy portion by butt swelling.展开更多
The geometric accuracy of topographic mapping with high-resolution remote sensing images is inevita-bly affected by the orbiter attitude jitter.Therefore,it is necessary to conduct preliminary research on the stereo m...The geometric accuracy of topographic mapping with high-resolution remote sensing images is inevita-bly affected by the orbiter attitude jitter.Therefore,it is necessary to conduct preliminary research on the stereo mapping camera equipped on lunar orbiter before launching.In this work,an imaging simulation method consid-ering the attitude jitter is presented.The impact analysis of different attitude jitter on terrain undulation is conduct-ed by simulating jitter at three attitude angles,respectively.The proposed simulation method is based on the rigor-ous sensor model,using the lunar digital elevation model(DEM)and orthoimage as reference data.The orbit and attitude of the lunar stereo mapping camera are simulated while considering the attitude jitter.Two-dimensional simulated stereo images are generated according to the position and attitude of the orbiter in a given orbit.Experi-mental analyses were conducted by the DEM with the simulated stereo image.The simulation imaging results demonstrate that the proposed method can ensure imaging efficiency without losing the accuracy of topographic mapping.The effect of attitude jitter on the stereo mapping accuracy of the simulated images was analyzed through a DEM comparison.展开更多
基金Supported by National Natural Science Foundation(30770124)~~
文摘[ Objective] The aim of this study was to solve the problem of photographing small flowers and fruits with a common digital camera in field. [Method] Firstly, the photographic mode of a common digital camera was set as ＂macro＂ （or ＂soft snap＂ ） and ＂flash off＂. Secondly, the small flower or fruit was magnified with a magnifying glass, and then the magnified flower or fruit was automatically focused with the digital camera lens. After automatic focusing, the shutter button was pressed and the photograph finished. [Result] With this method, the clear inflo- rescence or floral photographs of Eragrostis pilosa （ Gramineae ） , Bidens biternata （Compositae） and Tribulus terrester （Zygophllaceae） were obtained in field. [ Conclusion] The optical system of a digital camera has been changed by the magnifying glass, which improves the photographic function of a common digital camera to small flowers and fruits, and also easily gets their clear photographs.
基金Projects NCET-04-0484 supported by the New-Century Outstanding Young Scientist Program from the Ministry of Education and D0605046040191-101Beijing Science and Technology Program
文摘The objective of this paper is to improve the monitoring speed and precision of fractional vegetation cover (fc). It mainly focuses on fc estimation when fcmax and fcmin are not approximately equal to 100% and 0%, respectively due to using remote sensing image with medium or low spatial resolution. Meanwhile, we present a new method of fc estimation based on a random set of fc maximum and minimum values from digital camera (DC) survey data and a di- midiate pixel model. The results show that this is a convenient, efficient and accurate method for fc monitoring, with the maximum error -0.172 and correlation coefficient of 0.974 between DC survey data and the estimated value of the remote sensing model. The remaining DC survey data can be used as verification data for the precision of the fc estimation. In general, the estimation of fc based on DC survey data and a remote sensing model is a brand-new development trend and deserves further extensive utilization.
文摘Positioning of screw holes is an important production procedure for steel construction connecting with bolts.In this paper,a new production method is presented,in which the digital camera is used for taking pictures of screw holes and other techniques are advanced.This paper also indicates that the pixels of CCD chip in photogrammetry should be chosen as all geometric units in an image,such as interior elements and all kinds of distortions.The measure can also simplify the camera calibration for determining the size of non-square pixel.
基金This work was supported by National Science and Technology Specific Projects[grant number 2012YQ1601850],[grant number 2013BAH42F03]the National Natural Science Foundation of China[grant number 61172174]+1 种基金the Program for New Century Excellent Talents in University[grant number NCET-12-0426]the Basic Research Program of Hubei Province[grant number 2013CFA024].
文摘This work describes a calibration process for inexpensive consumer cameras integrated into a low cost and compact aerial multi-view imager for remote sensing and photogrammetry.The main advantage of this design is to make the filming component lightweight and rapidly deployable,as well as reducing cost when compared with mainstream commercial oblique imagery.An in situ flight test was carried out in Guiyang.In that experiment,a meridian convergence-based approach was adopted to adjust preprocessing,the residue error and the captured images’exterior orientation linear and angular parameters were calculated by means of the direct geo-referencing approach yielding a favorable outcome for exterior orientation linear parameters of the camera,around 0.2–0.3 m deviation from the actual measured results at 1000 m flight above ground level.The camera’s exterior orientation angular parametersφ,ωwhose difference compared with the standard aerial aero triangulation approach reached a high accuracy level within the intended endurance of 0.005°.These results indicate that the compact implementation of the oblique aerial imager comprised of consumer level off-the-shelf digital cameras achieved competitive accuracy at a low cost and high versatility.
文摘Objective This study aimed to evaluate the ability of a digital fundus camera to observe the development of the anterior chamber angle(ACA)in premature infants.Methods Forty-eight eyes of preterm infants(n=48)were examined by a digital fundus camera to observe the development of the ACA.ACA grading was performed based on the visualization of the anterior chamber structures according to the Scheie Angle Depth Evaluating System.Results ACA images from all 48 infants were successfully acquired using RetCam3.The corrected gestational age ranged from 30 weeks to 49 weeks,which covered the period from 2 months preterm to>2 months post-term.As the corrected gestational age increased,the corrected gestational age grading was significantly decreased.The mean corrected gestational ages of the infants corresponding to the ACA classification from grade IV to grade 0 were 32.75±1.89,37.20±1.30,39.75±2.38,40.56±2.24,and 44.23±2.14 weeks,respectively,which were all significantly different(P<0.05).The regression analysis showed a linear correlation between the grading of the ACA and the corrected gestational age(R2=0.724,P=0.0001).Conclusion The ACA of a full-term newborn can be fully detected and evaluated by a digital fundus camera.For premature infants,part of the ACA is not visible physiologically;however,it should not be misdiagnosed as angle closure or a narrow angle.
基金National Natural Science Foundation of China(30227001)
文摘Frame rate is corresponding to the temporal resolution and the number of the pixels of the picture is corresponding to the spatial resolution. They are both very important for the researchers. The ideal image analysis and processing system should have high spatiotemporal characteristics, which is much expensive in practical use. A new method to enhance dynamic frame rate using multi-digital camera(DC) is proposed and the result shows that it could increase the frame rate effectively and decreases the cost in practical use.
基金This work was supported by National Natural Science Foundation of China No.19775010.
文摘A digital camera measuring system has been used successfully to measure the space fluctuation behaviors of Induced Dielectric Barrier Discharge (IDBD) plasma at atmospheric pres- sure. The experimental results showed that: (1) The uniformity of electron temperature in space depends on discharge condition and structure of web electrode. For a certain web electrode the higher the discharge voltage is, the more uniform distribution of electron temperature in space will be. For a certain discharge the finer and denser the holes on web electrode are, the more uniform distribution of electron temperature in space will be (2). Digital camera is an available equipment to measure some behaviors of the plasma working at atmospheric pressure.
文摘用数码相机拍得的相片,在保存和网络传输方面有不容置疑的优越性,因此越来越多的人开始使用数码相机。但是我们不得不承认,它在成像质量方面还不能完全替代传统的相机。在你的数码像册里有没有一些太亮、太暗或者有杂点的问题照片呢?不要以为它们没救了哦,看了今天介绍的方法你就会知道,其实要给它们做美容一点都不难,只要一分钟就可以让你的相片白净又明亮! 咱们要用的这一系列美容工具叫做:Digital camera Tools(本文介绍的软件都可在http://www.mediachance.com/digicam/下载),这些简单又实用的小工具基本上可以解决数码相片中存在的大部分常见问题,比如:偏色、亮度不正常、有杂点等,对传统相片中的类似问题也有一定的作用。每一种工具都有它的适用范围,如果你的照片不在其适用范围之内,或者原本就拍得不错的话,那你可能就看不到太大的差别哦!
基金National Natural Science Foundation of China(No.61227003,61171179,61302159)Natural Science Foundation of Shanxi Province(No.2012021011-2)+2 种基金Research Project Supported by Shanxi Scholarship Council of China(No.2013-083)Specialized Research Fund for the Doctoral Program of Higher Education,China(No.20121420110006)Top Science and Technology Innovation Teams of Higher Learning Institutions of Shanxi Province,China
文摘Because single line-scan camera loses light in the edge of the sensor when the field of view is large, a mosaic cam- era based on field programmable gate array （FPGA） is presented by putting multiple cameras arranged in a straight line to share the field of view and reduce the view angle of every camera. For detecting doping micro particles with the designed mosaic line-scan camera, a detection algorithm of the target＇s location in FPGA is proposed. Finally, the practicability and stability of the system were validated experimentally. The results of the experiment show that the camera can get images clearly with less light loss and can accurately distinguish the target and the background.
基金Supported by the National Basic Research Program (973 Program) of China (No.2007CB407206)the National Natural Science Foundation of China (No.40371053)
文摘Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shrub-grasses (G) separately in a subtropical forest area in Nanjing, China. Both upward and downward photographs were taken with a digital camera in 72 quadrats (10 m × 10 m each). Fifteen models were established and validated. Models jointly using both T and G performed better than those using the T and G separately. The best model, TG = T + G- 1.134 × T × G- 0.025 (R2 = 0.9115, P < 0.01, root mean squared error = 0.0789), is recommended for application. This model provides a good way to obtain total forest VFC values through taking tree and shrub-grass photos on ground below tree canopy rather than above tree canopy.
基金financially supported by the scientific research projects coordination unit of Akdeniz University,Project No.FBA-2015-446
文摘A difficult problem in forestry is tree inventory.In this study, a GoProHero attached to a small unmanned aerial vehicle was used to capture images of a small area covered by pinus pinea trees. Then, a digital surface model was generated with image matching. The elevation model representing the terrain surface, a ‘digital terrain model’,was extracted from the digital surface model using morphological filtering. Individual trees were extracted by analyzing elevation flow on the digital elevation model because the elevation reached the highest value on the tree peaks compared to the neighborhood elevation pixels. The quality of the results was assessed by comparison with reference data for correctness of the estimated number of trees. The tree heights were calculated and evaluated with ground truth dataset. The results showed 80% correctness and 90% completeness.
文摘We develop a new technique to measure the exact upper diameters of trees that is comparatively simple and inexpensive. We can measure the diameters of entire tree trunks efficiently and with high precision. The system uses a digital camera with a ~15 - 30× telephoto lens to take a photograph that can be used for measuring the diameter of the upper part of a comparatively slender tree trunk. Since this method requires a measuring distance and the height of the target point in the image, a range finder capable of measuring angles was combined with the main digiscoping system. A range finder sensor uses a laser and makes a 360 degree angle of observation possible. The diameter of a target position of the objective tree can be obtained by measuring the digital image using image editing software and calculations from spreadsheet software. We focus on the Japanese cedar species in the southwestern part of Japan. Photographic measurements were obtained prior to thinning. The estimates that we obtained largely agree with the true measurements of all trees. With regard to the estimated accuracy of all measured trees, the maximum error ratio was 7.0% (1.45 cm), with a ~2% - 4% error for most of the estimated results. Although the absolute value of the estimation error was 1.87 cm (5.3%) at the maximum (9.87 m in height and 35.5 cm in diameter), an estimation accuracy of <1 cm was reproduced in almost all measurements except for the extreme hypertrophy portion by butt swelling.
基金Supported by the National Natural Science Foundation of China(42221002,42171432)Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)the Fundamental Research Funds for the Central Universities.
文摘The geometric accuracy of topographic mapping with high-resolution remote sensing images is inevita-bly affected by the orbiter attitude jitter.Therefore,it is necessary to conduct preliminary research on the stereo mapping camera equipped on lunar orbiter before launching.In this work,an imaging simulation method consid-ering the attitude jitter is presented.The impact analysis of different attitude jitter on terrain undulation is conduct-ed by simulating jitter at three attitude angles,respectively.The proposed simulation method is based on the rigor-ous sensor model,using the lunar digital elevation model(DEM)and orthoimage as reference data.The orbit and attitude of the lunar stereo mapping camera are simulated while considering the attitude jitter.Two-dimensional simulated stereo images are generated according to the position and attitude of the orbiter in a given orbit.Experi-mental analyses were conducted by the DEM with the simulated stereo image.The simulation imaging results demonstrate that the proposed method can ensure imaging efficiency without losing the accuracy of topographic mapping.The effect of attitude jitter on the stereo mapping accuracy of the simulated images was analyzed through a DEM comparison.
