Image segmentation remains one of the major challenges in image analysis.And soft image segmentation has been widely used due to its good effect.Fuzzy clustering algorithms are very popular in soft segmentation.A new ...Image segmentation remains one of the major challenges in image analysis.And soft image segmentation has been widely used due to its good effect.Fuzzy clustering algorithms are very popular in soft segmentation.A new soft image segmentation method based on center-free fuzzy clustering is proposed.The center-free fuzzy clustering is the modified version of the classical fuzzy C-means ( FCM ) clustering.Different from traditional fuzzy clustering , the center-free fuzzy clustering does not need to calculate the cluster center , so it can be applied to pairwise relational data.In the proposed method , the mean-shift method is chosen for initial segmentation firstly , then the center-free clustering is used to merge regions and the final segmented images are obtained at last.Experimental results show that the proposed method is better than other image segmentation methods based on traditional clustering.展开更多
The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese...The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS)and is due for launch in 2025.SXI is a compact X-ray telescope with a wide field-of-view(FOV)capable of encompassing large portions of Earth’s magnetosphere from the vantage point of the SMILE orbit.SXI is sensitive to the soft X-rays produced by the Solar Wind Charge eXchange(SWCX)process produced when heavy ions of solar wind origin interact with neutral particles in Earth’s exosphere.SWCX provides a mechanism for boundary detection within the magnetosphere,such as the position of Earth’s magnetopause,because the solar wind heavy ions have a very low density in regions of closed magnetic field lines.The sensitivity of the SXI is such that it can potentially track movements of the magnetopause on timescales of a few minutes and the orbit of SMILE will enable such movements to be tracked for segments lasting many hours.SXI is led by the University of Leicester in the United Kingdom(UK)with collaborating organisations on hardware,software and science support within the UK,Europe,China and the United States.展开更多
Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the sof...Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.Three CCDs have been characterised,the two flight devices and the flight spa re.This has been carried out at the Open University in a bespo ke cleanroom measure ment facility.The results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.The se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented.展开更多
The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)Soft X-ray Imager(SXI)will shine a spotlight on magnetopause dynamics during magnetic reconnection.We simulate an event with a southward interplanetary magne...The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)Soft X-ray Imager(SXI)will shine a spotlight on magnetopause dynamics during magnetic reconnection.We simulate an event with a southward interplanetary magnetic field turning and produce SXI count maps with a 5-minute integration time.By making assumptions about the magnetopause shape,we find the magnetopause standoff distance from the count maps and compare it with the one obtained directly from the magnetohydrodynamic(MHD)simulation.The root mean square deviations between the reconstructed and MHD standoff distances do not exceed 0.2 RE(Earth radius)and the maximal difference equals 0.24 RE during the 25-minute interval around the southward turning.展开更多
Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosph...Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)aims to capture two-dimensional(2-D)images of the Earth’s magnetosheath by using soft X-ray imaging.However,the observed 2-D images are affected by many noise factors,destroying the contained information,which is not conducive to the subsequent reconstruction of the three-dimensional(3-D)structure of the magnetopause.The analysis of SXI-simulated observation images shows that such damage cannot be evaluated with traditional restoration models.This makes it difficult to establish the mapping relationship between SXIsimulated observation images and target images by using mathematical models.We propose an image restoration algorithm for SXIsimulated observation images that can recover large-scale structure information on the magnetosphere.The idea is to train a patch estimator by selecting noise–clean patch pairs with the same distribution through the Classification–Expectation Maximization algorithm to achieve the restoration estimation of the SXI-simulated observation image,whose mapping relationship with the target image is established by the patch estimator.The Classification–Expectation Maximization algorithm is used to select multiple patch clusters with the same distribution and then train different patch estimators so as to improve the accuracy of the estimator.Experimental results showed that our image restoration algorithm is superior to other classical image restoration algorithms in the SXI-simulated observation image restoration task,according to the peak signal-to-noise ratio and structural similarity.The restoration results of SXI-simulated observation images are used in the tangent fitting approach and the computed tomography approach toward magnetospheric reconstruction techniques,significantly improving the reconstruction results.Hence,the proposed technology may be feasible for processing SXI-simulated observation images.展开更多
Flow cytometry and image analysis technique were used to quantltate the nuclei of various soft tissue tumors. A single representing section from soft tissue sarcoma was used for histologic grading. Histologlc and cyto...Flow cytometry and image analysis technique were used to quantltate the nuclei of various soft tissue tumors. A single representing section from soft tissue sarcoma was used for histologic grading. Histologlc and cytometric comparative analyses showed that all 21 benign tumors were diploid. Among 62 cases of soft tissue sarcoma, 45(73%) were aneuploid. There was a significant difference in the nuclear area between benign and malignant tumors (P<0. 01), dlploid and aneuploid tumors (P<0. 05). The two new techniques are valuable In cellular quantitative measurement for soft tissue tumors.展开更多
Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous recon...Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few spacecraft.This work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch analysis.If the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution reconstructions.In this paper we explore the reconstruction using,two,three,and four spacecraft.We show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.展开更多
The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the Chinese Academy of Sciences(CAS)and the European Space Agency(ESA),aiming to understand the interaction ...The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the Chinese Academy of Sciences(CAS)and the European Space Agency(ESA),aiming to understand the interaction of the solar wind with the Earth’s magnetosphere in a global manner.As of May 2024,the SMILE mission is in phase-D with an expected launch date of September 2025.This report summarizes developments in the mission during the past two years.展开更多
We propose to use the Moon as a platform to obtain a global view of Earth's magnetosphere by a Lunar-based Soft X-ray Imager(LSXI).LSXI is a wide field-of-view Soft X-ray telescope,which can obtain X-ray images of...We propose to use the Moon as a platform to obtain a global view of Earth's magnetosphere by a Lunar-based Soft X-ray Imager(LSXI).LSXI is a wide field-of-view Soft X-ray telescope,which can obtain X-ray images of Earth's magnetosphere based on the solar wind charge exchange(SWCX)X-ray emission.Global perspective is crucial to understand the overall interaction of the solar wind with magnetosphere.LSXI is capable of continuously monitoring the evolution of geospace conditions under the impact of the solar wind by simultaneous observation of the bow shock,magnetosheath,magnetopause and cusps for the first time.This proposal is answering the call for the Chinese Lunar Exploration Program Phase IV.展开更多
Imaging techniques provide essential information in astronomical and space physics studies.The Soft X-ray Imager(SXI)will obtain images of the Earth’s magnetosphere via the solar wind charge exchange process in a glo...Imaging techniques provide essential information in astronomical and space physics studies.The Soft X-ray Imager(SXI)will obtain images of the Earth’s magnetosphere via the solar wind charge exchange process in a global view.However,it is a challenge to reconstruct its 3-D structures from the observed 2-D image(s).In this paper,a recently proposed method,Tangent Fitting Approach(TFA),is validated to reconstruct the large-scale magnetopause from a single X-ray image obtained by instrument simulation.It is revealed that the large-scale magnetopause under a medium solar wind number density can be well reconstructed,although the locations of maximum X-ray photon counts are scattered in the image due to instrumental effects and diffusive sky background.Higher solar wind number density leads to stronger signals and further leads to better reconstruction results.For lower solar wind density,the X-ray maximum photon counts may not be identified from the SXI simulations,preprocessing of the images shall be considered before applying TFA.Furthermore,the subsolar magnetopause can be well derived when the satellite is on the dayside orbits.展开更多
The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission aims at deepening our understanding of the interaction of the solar wind with the Earth magnetosphere.It is the first time that ESA and CAS jointly s...The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission aims at deepening our understanding of the interaction of the solar wind with the Earth magnetosphere.It is the first time that ESA and CAS jointly select,design,implement,launch,and operate a space mission.The mission was adopted by CAS in November 2016 and by ESA in March 2019 with a target launch date by the end of 2023.展开更多
The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS),aiming to understand the interaction ...The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS),aiming to understand the interaction of the solar wind with the Earth’s magnetosphere in a global manner.The mission was adopted by CAS in November 2016 and by ESA in March 2019 with a target launch date in the year 2024-2025.We report the recent progress of SMILE mission by May,2022.展开更多
Over the past decades,imaging and spectroscopy techniques have been developed rapidly with widespread applications in non-destructive agro-food quality determination.Seeds are one of themost fundamental elements of ag...Over the past decades,imaging and spectroscopy techniques have been developed rapidly with widespread applications in non-destructive agro-food quality determination.Seeds are one of themost fundamental elements of agriculture and forestry.Seed viability is of great significance in seed quality characteristics reflecting potential seed germination,and there is a great need for a quick and effective method to determine the germination condition and viability of seeds prior to cultivate,sale and plant.Some researches based on spectra and/or image processing and analysis have been explored in terms of the external and internal quality of a variety of seeds.Many attempts have been made in image segmentation and spectra correction methods to predict seed quality using various traditional and novel methods.This review focuses on the comparative introduction,development and applications of emerging techniques in the analysis of seed viability,in particular,near infrared spectroscopy,hyperspectral and multispectral imaging,Raman spectroscopy,infrared thermography,and soft X-ray imaging methods.The basic theories,principle components,relative chemometric processing,analytical methods and prediction accuracies are reported and compared.Additionally,on the foundation of the observed applications,the technical challenges and future outlook for these emerging techniques are also discussed.展开更多
基金Supported by the National Natural Science Foundation of China(61103058,61233011)
文摘Image segmentation remains one of the major challenges in image analysis.And soft image segmentation has been widely used due to its good effect.Fuzzy clustering algorithms are very popular in soft segmentation.A new soft image segmentation method based on center-free fuzzy clustering is proposed.The center-free fuzzy clustering is the modified version of the classical fuzzy C-means ( FCM ) clustering.Different from traditional fuzzy clustering , the center-free fuzzy clustering does not need to calculate the cluster center , so it can be applied to pairwise relational data.In the proposed method , the mean-shift method is chosen for initial segmentation firstly , then the center-free clustering is used to merge regions and the final segmented images are obtained at last.Experimental results show that the proposed method is better than other image segmentation methods based on traditional clustering.
基金funding and support from the United Kingdom Space Agency(UKSA)the European Space Agency(ESA)+5 种基金funded and supported through the ESA PRODEX schemefunded through PRODEX PEA 4000123238the Research Council of Norway grant 223252funded by Spanish MCIN/AEI/10.13039/501100011033 grant PID2019-107061GB-C61funding and support from the Chinese Academy of Sciences(CAS)funding and support from the National Aeronautics and Space Administration(NASA)。
文摘The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS)and is due for launch in 2025.SXI is a compact X-ray telescope with a wide field-of-view(FOV)capable of encompassing large portions of Earth’s magnetosphere from the vantage point of the SMILE orbit.SXI is sensitive to the soft X-rays produced by the Solar Wind Charge eXchange(SWCX)process produced when heavy ions of solar wind origin interact with neutral particles in Earth’s exosphere.SWCX provides a mechanism for boundary detection within the magnetosphere,such as the position of Earth’s magnetopause,because the solar wind heavy ions have a very low density in regions of closed magnetic field lines.The sensitivity of the SXI is such that it can potentially track movements of the magnetopause on timescales of a few minutes and the orbit of SMILE will enable such movements to be tracked for segments lasting many hours.SXI is led by the University of Leicester in the United Kingdom(UK)with collaborating organisations on hardware,software and science support within the UK,Europe,China and the United States.
文摘Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.Three CCDs have been characterised,the two flight devices and the flight spa re.This has been carried out at the Open University in a bespo ke cleanroom measure ment facility.The results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.The se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented.
基金support from the UK Space Agency under Grant Number ST/T002964/1partly supported by the International Space Science Institute(ISSI)in Bern,through ISSI International Team Project Number 523(“Imaging the Invisible:Unveiling the Global Structure of Earth’s Dynamic Magnetosphere”)。
文摘The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)Soft X-ray Imager(SXI)will shine a spotlight on magnetopause dynamics during magnetic reconnection.We simulate an event with a southward interplanetary magnetic field turning and produce SXI count maps with a 5-minute integration time.By making assumptions about the magnetopause shape,we find the magnetopause standoff distance from the count maps and compare it with the one obtained directly from the magnetohydrodynamic(MHD)simulation.The root mean square deviations between the reconstructed and MHD standoff distances do not exceed 0.2 RE(Earth radius)and the maximal difference equals 0.24 RE during the 25-minute interval around the southward turning.
基金supported by the National Natural Science Foundation of China(Grant Nos.42322408,42188101,41974211,and 42074202)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDJ-SSW-JSC028)+1 种基金the Strategic Priority Program on Space Science,Chinese Academy of Sciences(Grant Nos.XDA15052500,XDA15350201,and XDA15014800)supported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.Y202045)。
文摘Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)aims to capture two-dimensional(2-D)images of the Earth’s magnetosheath by using soft X-ray imaging.However,the observed 2-D images are affected by many noise factors,destroying the contained information,which is not conducive to the subsequent reconstruction of the three-dimensional(3-D)structure of the magnetopause.The analysis of SXI-simulated observation images shows that such damage cannot be evaluated with traditional restoration models.This makes it difficult to establish the mapping relationship between SXIsimulated observation images and target images by using mathematical models.We propose an image restoration algorithm for SXIsimulated observation images that can recover large-scale structure information on the magnetosphere.The idea is to train a patch estimator by selecting noise–clean patch pairs with the same distribution through the Classification–Expectation Maximization algorithm to achieve the restoration estimation of the SXI-simulated observation image,whose mapping relationship with the target image is established by the patch estimator.The Classification–Expectation Maximization algorithm is used to select multiple patch clusters with the same distribution and then train different patch estimators so as to improve the accuracy of the estimator.Experimental results showed that our image restoration algorithm is superior to other classical image restoration algorithms in the SXI-simulated observation image restoration task,according to the peak signal-to-noise ratio and structural similarity.The restoration results of SXI-simulated observation images are used in the tangent fitting approach and the computed tomography approach toward magnetospheric reconstruction techniques,significantly improving the reconstruction results.Hence,the proposed technology may be feasible for processing SXI-simulated observation images.
文摘Flow cytometry and image analysis technique were used to quantltate the nuclei of various soft tissue tumors. A single representing section from soft tissue sarcoma was used for histologic grading. Histologlc and cytometric comparative analyses showed that all 21 benign tumors were diploid. Among 62 cases of soft tissue sarcoma, 45(73%) were aneuploid. There was a significant difference in the nuclear area between benign and malignant tumors (P<0. 01), dlploid and aneuploid tumors (P<0. 05). The two new techniques are valuable In cellular quantitative measurement for soft tissue tumors.
基金supported by NNSFC grants 42322408,42188101 and 42074202the Strategic Pioneer Program on Space Science,CAS Grant nos.XDA15350201+2 种基金in part by the Research Fund from the Chinese Academy of Sciencesthe Specialized Research Fund for State Key Laboratories of Chinasupported by the Young Elite Scientists Sponsorship Program(CAST-Y202045)。
文摘Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few spacecraft.This work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch analysis.If the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution reconstructions.In this paper we explore the reconstruction using,two,three,and four spacecraft.We show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.
基金Founded by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(XDA15350000)。
文摘The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the Chinese Academy of Sciences(CAS)and the European Space Agency(ESA),aiming to understand the interaction of the solar wind with the Earth’s magnetosphere in a global manner.As of May 2024,the SMILE mission is in phase-D with an expected launch date of September 2025.This report summarizes developments in the mission during the past two years.
基金supported by the National Natural Science Foundation of China(Grant Nos.41731070,41974211,41774173,41731070)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDJ-SSW-JSC028)the Strategic Pioneer Program on Space Science,Chinese Academy of Sciences(Grant Nos.XDA15052500,XDA15350201)。
文摘We propose to use the Moon as a platform to obtain a global view of Earth's magnetosphere by a Lunar-based Soft X-ray Imager(LSXI).LSXI is a wide field-of-view Soft X-ray telescope,which can obtain X-ray images of Earth's magnetosphere based on the solar wind charge exchange(SWCX)X-ray emission.Global perspective is crucial to understand the overall interaction of the solar wind with magnetosphere.LSXI is capable of continuously monitoring the evolution of geospace conditions under the impact of the solar wind by simultaneous observation of the bow shock,magnetosheath,magnetopause and cusps for the first time.This proposal is answering the call for the Chinese Lunar Exploration Program Phase IV.
基金supported by the National Natural Science Foundation of China(Grant Nos.41731070,41974211,42074202,41774173)the Key Research Program of Frontier Sciences CAS(Grant No.QYZDJ-SSW-JSC028)+1 种基金the Strategic Pioneer Program on Space Science,CAS(Grant Nos.XDA15052500,XDA15350201)supported by the Youth Innovation Promotion Association of CAS(Grant No.Y202045)。
文摘Imaging techniques provide essential information in astronomical and space physics studies.The Soft X-ray Imager(SXI)will obtain images of the Earth’s magnetosphere via the solar wind charge exchange process in a global view.However,it is a challenge to reconstruct its 3-D structures from the observed 2-D image(s).In this paper,a recently proposed method,Tangent Fitting Approach(TFA),is validated to reconstruct the large-scale magnetopause from a single X-ray image obtained by instrument simulation.It is revealed that the large-scale magnetopause under a medium solar wind number density can be well reconstructed,although the locations of maximum X-ray photon counts are scattered in the image due to instrumental effects and diffusive sky background.Higher solar wind number density leads to stronger signals and further leads to better reconstruction results.For lower solar wind density,the X-ray maximum photon counts may not be identified from the SXI simulations,preprocessing of the images shall be considered before applying TFA.Furthermore,the subsolar magnetopause can be well derived when the satellite is on the dayside orbits.
基金Supported by Strategic Priority Program on Space Science,CAS(XDA15350000)National Natural Science Foundation of China(41731070)+1 种基金Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-JSC028)and Strategic Pionner Program on Space Science,CAS(XDA15052500)。
文摘The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission aims at deepening our understanding of the interaction of the solar wind with the Earth magnetosphere.It is the first time that ESA and CAS jointly select,design,implement,launch,and operate a space mission.The mission was adopted by CAS in November 2016 and by ESA in March 2019 with a target launch date by the end of 2023.
基金Supported by Strategic Priority Program on Space Science,CAS(XDA15350000)National Natural Science Foundation of China(41731070)+1 种基金Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-JSC028)Strategic Pioneer Program on Space Science,CAS(XDA15052500)。
文摘The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS),aiming to understand the interaction of the solar wind with the Earth’s magnetosphere in a global manner.The mission was adopted by CAS in November 2016 and by ESA in March 2019 with a target launch date in the year 2024-2025.We report the recent progress of SMILE mission by May,2022.
基金This work was financially supported by the National Natural Science Foundation of China(31801262 and 31871523)National Key Research and Development Program of China(2018YFD0101004).
文摘Over the past decades,imaging and spectroscopy techniques have been developed rapidly with widespread applications in non-destructive agro-food quality determination.Seeds are one of themost fundamental elements of agriculture and forestry.Seed viability is of great significance in seed quality characteristics reflecting potential seed germination,and there is a great need for a quick and effective method to determine the germination condition and viability of seeds prior to cultivate,sale and plant.Some researches based on spectra and/or image processing and analysis have been explored in terms of the external and internal quality of a variety of seeds.Many attempts have been made in image segmentation and spectra correction methods to predict seed quality using various traditional and novel methods.This review focuses on the comparative introduction,development and applications of emerging techniques in the analysis of seed viability,in particular,near infrared spectroscopy,hyperspectral and multispectral imaging,Raman spectroscopy,infrared thermography,and soft X-ray imaging methods.The basic theories,principle components,relative chemometric processing,analytical methods and prediction accuracies are reported and compared.Additionally,on the foundation of the observed applications,the technical challenges and future outlook for these emerging techniques are also discussed.
