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1.
Of all the galaxies in the visible part of the universe, 500 million are seen through intervening galaxies. In some instances the foreground galaxy will act as a gravitational lens and produce distorted and (in brightness) greatly amplified images of the galaxy behind it; such images may simulate starlike superluminous objects such as quasars (quasi-stellar objects). The number of gravitational lenses is several times greater than the number of quasars yet observed. In other instances the superposition of the image upon a visible foreground galaxy may simulate morphological configurations resembling N-type, dumbbell, spiral, or barred-spiral galaxies. 相似文献
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Application of a fully automatic analysis tool to assess the activity of broiler chickens with different gait scores 总被引：1，自引：0，他引：1
A. Aydin 《Computers and Electronics in Agriculture》2010,73(2):194-199
Monitoring the activity of broilers is a potential way for determining gait score level at commercial farms. In this study, a fully automatic monitoring technique was developed to measure the activity of broiler chickens with different gait score levels. We carried out two experiments in order to assess the relationship between gait scores obtained by human experts and activity levels quantified by an automatic image monitoring system. The chickens were scored for their degree of lameness by experts according to the method of Kestin et al. (1992). For each experiment, a total of 30 birds, on day 32 were selected from a local commercial farm. Five birds were selected in each of six gait score groups (GS0-GS5). The activity levels were obtained for all gait scores by using an automatic image monitoring system. For this purpose, video surveillance images of broilers with six different predefined gait scores were analysed. In both experiments, there was a significant relation between gait score by experts and activity monitored by image analysis. The broilers with gait score 3 (GS3) showed significantly higher activities than the other gait scores in both experiments (P < 0.05), possibly due to their need for more feed. In both experiment, GS4 and GS5 showed significantly lower activities (P < 0.05). Overall, the results show that automatic camera monitoring system can provide an automatic tool in determination the activity in relation to gait score. This activity information can be used further to identify the effects of gait score on broiler behaviour. 相似文献
3.
【目的】准确获取红富士苹果的分级指标，为实现多特征融合的苹果分级提供依据。【方法】以均值滤波、全局亮度均衡化与图像裁剪方法，预处理实验所需的苹果图像；使用K-means聚类算法、OTSU最大类间方差法，将苹果灰度图转换为二值图；利用二值图与苹果原图的异或运算，提取苹果轮廓；采用苹果的二值图计算苹果的果实区域大小；使用颜色空间转换RGB-HSV中H通道划分果实红色区域；通过构建掩膜、形态学操作判断果体是否含有缺陷及计算其面积；构建最小外接矩形计算苹果的果径及果形；利用KNN分类算法实现多特征融合的苹果在线自动分级。【结果】基于K-means聚类与KNN分类相结合的苹果在线分级方法，在优于传统图像阈值分割效果的基础上，特级果分级准确率为97.14%,一级果分级准确率为100%,二级果分级准确率为93.75%,等外果分级准确率为100%,综合分级准确率达到97%。【结论】100个苹果测试准确率达到97%,验证了该分级方法的可行性与准确性。 相似文献
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Combined optical and radio images of galaxies can provide new insights into the sizes, masses, and possible evolution of these objects. Deep optical and neutral hydrogen images of Markarian 348, a type 2 Seyfert galaxy, show that it is a gigantic spiral (perhaps the largest known non-cluster galaxy). Measurements of the neutral hydrogen velocity field and spiral structure, and detection of an optical "tidal plume," all provide evidence that it has been subject to tidal disruption. The measured velocities yield a mass-to-light ratio for this object (within a radius of 130 kiloparsecs from its nucleus) that is similar to the ratio found for the inner regions of most galaxies of similar type. This is one of the few cases where detailed velocity measurements have demonstrated that a galaxy with an active nucleus has been subject to extensive tidal perturbation. 相似文献
6.
Xiangyu Song Toon Leroy Erik Vranken Willem Maertens Bart Sonck Daniel Berckmans 《Computers and Electronics in Agriculture》2008,64(1):39
The occurrence of lameness in dairy cattle is of increasing importance in herd health management and herd productivity. Current practice, involves visual observation by human experts to score cow's locomotion in order to estimate the lameness in the herd. The trackway defined as “hind hoof compared to fore hoof position” is one of the main components to score the locomotion. However, because of the time-consuming observation method, lame cows are undiagnosed until the problem has become severe. Up till now there is no automatic (visual) method for detecting lameness in dairy cattle. The objective of our study was to make an automatic system for continuous on-farm detection and prediction of lameness in the farm by using vision techniques. The current focus was on demonstrating the possibility of capturing cow's hoof locations by vision and strong correlation between automatically calculated hoof trackway and visual locomotion scores. Fifteen selected lactating cows were scored visually by four trained observers at the Gent University Research Farm. Scoring varied from 1 (normal walking) to 5 (extremely lame). Side-view images with resolution of 1024 × 768 pixels were recorded when cows passed an experimental set-up freely. Recorded videos were split into sequences of bitmap images. After background subtraction, binary image operations, calibration and hoof separation, the trackway information containing hoof location in the real world and its related time in the video was calculated. The accuracy of automatically captured results was checked by comparing with the output from manually labeled hoof locations. The mean correlation coefficient of all measurements was 94.8%. Hence, the results suggest that the automatic method by vision analysis is feasible to present the cows’ real locomotion situations. The first result showed a positive linear relationship between cows’ trackways overlap and locomotion scores by human visualization. This research proved that vision techniques have great potential to be used for continuous quantification of lameness in cows. 相似文献
7.
The relics of disrupted satellite galaxies have been found around the Milky Way and Andromeda, but direct evidence of a satellite galaxy in the early stages of disruption has remained elusive. We have discovered a dwarf satellite galaxy in the process of being torn apart by gravitational tidal forces as it merges with a larger galaxy's dark matter halo. Our results illustrate the morphological transformation of dwarf galaxies by tidal interaction and the continued buildup of galaxy halos. 相似文献
8.
《Computers and Electronics in Agriculture》2009,65(2):85-92
In order to produce a high quality rubberwood fingerjoint with highly uniform colour, wood boards of naturally different shades and colours are required to be elaborately classified and grouped. Within each group, wood boards of comparable shade and colour are then cut and joined to form a highly uniform shade and colour fingerjoint of the required dimensions. Currently, many manufacturers in Thailand still rely heavily on a manual classification process by an expert. In this paper, an automatic approach based on a combination of an image processing technique and an artificial neural network is presented. The Kohonen self organizing map (SOM) is selected and used for training with modified histogram data from the hue colour component of the rubberwood boards’ images. The outcome SOM is then used to classify an unknown colour rubberwood board with a novel colour group identification algorithm. The overall approach has proved effective in classifying the unknown colour of boards with as high as 95% accuracy without human intervention. In many cases, the approach provides invaluable information to guide an operator to easily classify the remaining 5%. 相似文献
9.
叶片的形态测量在苗木生长自动监测中具有重要意义,在形态测量前首先要将完整的叶片从背景中提取出来.针对彩色苗木叶片图像的特点研究了利用几何活动轮廓模型进行完整叶片的自动分割的方法.首先利用图像的全局信息和C-V模型进行初始分割,当曲线到达目标边界附近时,利用改进的基于图像局部信息的能量模型进行边界的精确定位.该方法将C-... 相似文献
10.
Accurate face recognition is critical for many security applications. Current automatic face-recognition systems are defeated by natural changes in lighting and pose, which often affect face images more profoundly than changes in identity. The only system that can reliably cope with such variability is a human observer who is familiar with the faces concerned. We modeled human familiarity by using image averaging to derive stable face representations from naturally varying photographs. This simple procedure increased the accuracy of an industry standard face-recognition algorithm from 54% to 100%, bringing the robust performance of a familiar human to an automated system. 相似文献
11.
以2010年HJ-1号卫星CCD数据为主要数据源,采用面向对象分类方法,提取关中平原人工表面信息。在eCognition软件平台的支持下,综合影像光谱信息、纹理、形状和地理空间关系等特征参数,并添加DEM、Slope、TM数据、样本点数据以及特征指数等辅助信息,依据决策树分类思想,进行多尺度分割逐级提取地物类型。结果表明：利用HJ-1号卫星数据提取区域人工表面信息是可行的,采用面向对象的计算机自动分类方法提取人工表面信息的效率明显提高,且精度达到85.90%。 相似文献
12.
Three methods of automatic classification of leaf diseases are described based on high-resolution multispectral stereo images.
Leaf diseases are economically important as they can cause a loss of yield. Early and reliable detection of leaf diseases
has important practical relevance, especially in the context of precision agriculture for localized treatment with fungicides.
We took stereo images of single sugar beet leaves with two cameras (RGB and multispectral) in a laboratory under well controlled
illumination conditions. The leaves were either healthy or infected with the leaf spot pathogen Cercospora beticola or the rust fungus Uromyces betae. To fuse information from the two sensors, we generated 3-D models of the leaves. We discuss the potential of two pixelwise
methods of classification: k-nearest neighbour and an adaptive Bayes classification with minimum risk assuming a Gaussian mixture model. The medians of
pixelwise classification rates achieved in our experiments are 91% for Cercospora beticola and 86% for Uromyces betae. In addition, we investigated the potential of contextual classification with the so called conditional random field method,
which seemed to eliminate the typical errors of pixelwise classification. 相似文献
13.
基于叶片图像多特征融合的观叶植物种类识别 总被引：9，自引：4，他引：5
叶片图像特征提取对于植物自动分类识别有着重要的研究意义。本文以观叶植物叶片为研究对象,综合提取叶片图像的颜色、形状和纹理特征,基于支持向量机(SVM)原理提出了基于图像分析的观叶植物自动识别分类方法。通过对50种观叶植物样本图像进行训练和识别,与BP神经网络和KNN识别方法进行比较,本文所采用的SVM分类器的识别率能够达到91.41%,取得了较好的识别效果。 相似文献
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15.
深加工是目前我国水果产业发展的主方向。设计了基于神经网络的自动水果分类系统,包括系统的硬件构成和分类程序。其中图像的特征提取是水果分类程序的前提。提取了水果图像的形状、颜色、纹理3种主要特征,将3种特征向量输入到神经网络分类器进行分类识别。仿真结果表明,该方法实时性好,分类准确率高,可满足水果深加工生产的实用需要。 相似文献
16.
Smartt SJ Maund JR Hendry MA Tout CA Gilmore GF Mattila S Benn CR 《Science (New York, N.Y.)》2004,303(5657):499-503
We present the discovery of a red supergiant star that exploded as supernova 2003gd in the nearby spiral galaxy M74. The Hubble Space Telescope (HST) and the Gemini Telescope imaged this galaxy 6 to 9 months before the supernova explosion, and subsequent HST images confirm the positional coincidence of the supernova with a single resolved star that is a red supergiant of 8(+4)(-2) solar masses. This confirms both stellar evolution models and supernova theories predicting that cool red supergiants are the immediate progenitor stars of type II-plateau supernovae. 相似文献
17.
南方林区TM遥感图象组合方式研究 总被引：2，自引：0，他引：2
杨燕琼 《华南农业大学学报》1999,20(4):86-89
就南方林区ＴＭ遥感图象的多种组合方式进行了分析、对比、认为ＴＭ４、５、３的组合彩色图象及其数据较适用于南方森林植物类型之判读及计算机自动分类,ＴＭ４７２彩色产有利于幼林、疏林地、荒山等的判读;ＴＭ４２７彩色合成图对杉木林反映较好。 相似文献
18.
Machine vision for counting fruit on mango tree canopies 总被引：1，自引：0，他引：1
W. S. Qureshi A. Payne K. B. Walsh R. Linker O. Cohen M. N. Dailey 《Precision Agriculture》2017,18(2):224-244
Machine vision technologies hold the promise of enabling rapid and accurate fruit crop yield predictions in the field. The key to fulfilling this promise is accurate segmentation and detection of fruit in images of tree canopies. This paper proposes two new methods for automated counting of fruit in images of mango tree canopies, one using texture-based dense segmentation and one using shape-based fruit detection, and compares the use of these methods relative to existing techniques:—(i) a method based on K-nearest neighbour pixel classification and contour segmentation, and (ii) a method based on super-pixel over-segmentation and classification using support vector machines. The robustness of each algorithm was tested on multiple sets of images of mango trees acquired over a period of 3 years. These image sets were acquired under varying conditions (light and exposure), distance to the tree, average number of fruit on the tree, orchard and season. For images collected under the same conditions as the calibration images, estimated fruit numbers were within 16 % of actual fruit numbers, and the F1 measure of detection performance was above 0.68 for these methods. Results were poorer when models were used for estimating fruit numbers in trees of different canopy shape and when different imaging conditions were used. For fruit-background segmentation, K-nearest neighbour pixel classification based on colour and smoothness or pixel classification based on super-pixel over-segmentation, clustering of dense scale invariant feature transform features into visual words and bag-of-visual-word super-pixel classification using support vector machines was more effective than simple contrast and colour based segmentation. Pixel classification was best followed by fruit detection using an elliptical shape model or blob detection using colour filtering and morphological image processing techniques. Method results were also compared using precision–recall plots. Imaging at night under artificial illumination with careful attention to maintaining constant illumination conditions is highly recommended. 相似文献
19.
Volunteer potato is an increasing problem in crop rotations where winter temperatures are often not cold enough to kill tubers
leftover from harvest. Poor control, as a result of high labor demands, causes diseases like Phytophthora infestans to spread to neighboring fields. Therefore, automatic detection and removal of volunteer plants is required. In this research,
an adaptive Bayesian classification method has been developed for classification of volunteer potato plants within a sugar
beet crop. With use of ground truth images, the classification accuracy of the plants was determined. In the non-adaptive
scheme, the classification accuracy was 84.6 and 34.9% for the constant and changing natural light conditions, respectively.
In the adaptive scheme, the classification accuracy increased to 89.8 and 67.7% for the constant and changing natural light
conditions, respectively. Crop row information was successfully used to train the adaptive classifier, without having to choose
training data in advance. 相似文献
20.
Gomez JL Marscher AP Alberdi A Jorstad SG Garcia-Miro C 《Science (New York, N.Y.)》2000,289(5488):2317-2320
A 16-month sequence of radio images of the active galaxy 3C120 with the Very Long Baseline Array reveals a region in the relativistic jet where superluminal components flash on and off over time scales of months, while the polarization angle rotates. This can be explained by interaction between the jet and an interstellar cloud located about 8 parsecs from the center of the galaxy. The cloud, which rotates the polarization direction and possibly eclipses a section of the jet, represents a "missing link" between the ultradense broad-emission-line clouds closer to the center and the lower density narrow-emission-line clouds seen on kiloparsec scales. 相似文献