Systèmes imageurs 3D pour des applications agricoles : caractérisation de cultures et phénotypage de racines

The development of the concepts of precision agriculture and viticulture since the last three decades has shown the need to use first 2D image acquisition techniques and dedicated image processing. More and more needs concern now 3D images and information. The main ideas of this chapter is thus to present some innovations of the 3D tools and methods in the agronomic domain. This chapter will particularly focus on two main subjects such as the 3D characterization of crop using Shape from Focus or Structure from Motion techniques and the 3D use for root phenotyping using rhizotron system. Results presented show that 3D information allows to better characterize crucial crop morphometric parame…

3D image acquisition system based on shape from focus technique

agent Agrosup Dijon de l'UMREcolDurGEAPSI; This paper describes the design of a 3D image acquisition system dedicated to natural complex scenes composed of randomly distributed objects with spatial discontinuities. In agronomic sciences, the 3D acquisition of natural scene is difficult due to the complex nature of the scenes. Our system is based on the Shape from Focus technique initially used in the microscopic domain. We propose to adapt this technique to the macroscopic domain and we detail the system as well as the image processing used to perform such technique. The Shape from Focus technique is a monocular and passive 3D acquisition method that resolves the occlusion problem affecting…

Characterisation of centrifugal spreaders : from collection trays to high speed stereovision

AgrosupEAGEAPSICT1; Presenting Author Jürgen Vangeyte - ILVO, Agricultural Engineering, Belgium Description Precision fertilization requires accurate techniques for determining the spread pattern of centrifugal fertilizer spreaders. Traditionally, the spread pattern was determined by measuring the fertilizer distribution on the ground. Because such measurements are time consuming and complex, a high speed stereovision setup and dedicated image processing algorithms were developed for position and motion estimation of fertilizer grains leaving a centrifugal spreader. The measurements are combined with a ballistic flight model to predict the landing points of the individual grains and the act…

Solution de détection des maladies de la vigne par imagerie de drone. Diagnostic et réduction des pesticides à la parcelle

ARTICLE A NE PAS DIFFUSEREAGEAPSIAgrosupCT1; Solution de détection des maladies de la vigne par imagerie de drone. Diagnostic et réduction des pesticides à la parcelle

L'utilisation de la proxi-détection 3D pour la caractérisation du blé

Early detection of disease on leaves by image processing

International audience

Image acquisition and processing for precision farming applications

Initially developed for technical industrial sectors such as medicine or aeronautics, imaging technics are more and more used since 30 years in agriculture and viticulture. The development of acquisition tool and the decreasing of the calculation time allowed using imagery in laboratory under controlled conditions. At the beginning of the 90’s, the concept of Precision Farming has been developed in the USA, considering a field as a heterogeneous area needing different input in terms of fertiliser or protection product. In the same time, the aperture of the GPS system for civil applications has allowed the development of remote sensing domain. Combining GPS information and imagery conducted …

Mesure de netteté basée sur les descripteurs généralisés de Fourier appliquée à la reconstruction 3D

National audience

A 3-D stereovision simulator for centrifugal fertilizer granule spreading

International audience

Automatic analyzis of droplet impact by high speed imaging

International audience; The impact of agricultural activities on the water quality is the consequence of the loss of fertilisers (chemical fertilisers, livestock effluent, also referred to as farm fertiliser, food-processing effluent and sludge) and crop treatment products (phytosanitary products). This pollution may prevent certain uses of water, notably its use for human and animal food (groundwater and surface water), and leads to a deterioration in aquatic environments. In the domain of vineyard precision spraying research, one of the most important objectives is to minimize the volume of phytosanitary products. It is also to be more environmentally respectful with more effective vine l…

DAMAV project for vineyard disease detection by UAV imagery

AgrosupBAPGEAPSI; DAMAV project for vineyard disease detection by UAV imagery . CIRG-AgEng 2016, International Conférence on Agricultural Engineering, Automation, Environment and Food Safety

Protocol for the Definition of a Multi-Spectral Sensor for Specific Foliar Disease Detection: Case of “Flavescence Dorée”

Flavescence Doree (FD) is a contagious and incurable grapevine disease that can be perceived on leaves. In order to contain its spread, the regulations obligate winegrowers to control each plant and to remove the suspected ones. Nevertheless, this monitoring is performed during the harvest and mobilizes many people during a strategic period for viticulture. To solve this problem, we aim to develop a Multi-Spectral (MS) imaging device ensuring an automated grapevine disease detection solution. If embedded on a UAV, the tool can provide disease outbreaks locations in a geographical information system allowing localized and direct treatment of infected vines. The high-resolution MS camera aims…

Comparison of leaf surface roughness analysis methods by sensitivity to noise analysis

International audience; Surface roughness is of great interest in agricultural spraying because it is used to characterise leaf surface wettability to predict the behaviour of droplets on a leaf surface. In recent years, the use of texture analysis to estimate surface roughness has emerged. In this paper we propose to estimate leaf surface roughness by using an optimisation of the Generalized Fourier Descriptors method. This approach is then compared with two other standard methods in the literature, one based on grey level intensity variation and the other on wavelet decomposition. Since roughness has many definitions and each method is calculated differently, we propose a new approach to …

Texture, color and frequential proxy-detection image processing for crop characterization in a context of Precision Agriculture

High Speed Stereovision Setup for Position and Motion Estimation of Fertilizer Particles Leaving a Centrifugal Spreader

EA SPE GEAPSI; International audience; A 3D imaging technique using a high speed binocular stereovision system was developed in combination with corresponding image processing algorithms for accurate determination of the parameters of particles leaving the spinning disks of centrifugal fertilizer spreaders. Validation of the stereo-matching algorithm using a virtual 3D stereovision simulator indicated an error of less than 2 pixels for 90% of the particles. The setup was validated using the cylindrical spread pattern of an experimental spreader. A 2D correlation coefficient of 90% and a Relative Error of 27% was found between the experimental results and the (simulated) spread pattern obtai…

Measuring vine leaf roughness by image processing

International audience; In precision spraying, spray application efficiency depends on the pesticide application method, the phytosanitary product as well as the leaf surface properties. For environmental and economic reasons, the global trend is to reduce the pesticide application rate of the few approved active substances. Under these constraints, one of the challenges is to improve the efficiency of pesticide application. Different parameters can influence on pesticide application as nozzle types, liquid viscosity and leaf surface. Specific models have been developed showing that the predominant factor for the leaf is the leaf roughness, because it is related on adhesion mechanisms of li…

Nodulated root imaging within the high throughput plant phenotyping platform (PPHD, INRA, Dijon)

Présentation orale/ Communication avec actes

Imagerie pour les maladies de la vigne

La viticulture est confrontée à des problèmes majeurs dont la lutte contre les maladies cryptogamiques telles que l’oïdium ou la pourriture grise. Elle utilise alors majoritairement des produits phytosanitaires de synthèse susceptibles de poser des problèmes environnementaux et sanitaires, et de favoriser la sélection de souches de microorganismes pathogènes résistantes. Dans le cadre du plan Ecophyto 2018, la recherche de méthodes visant à diminuer, voire à remplacer, les fongicides de synthèse au vignoble, a pris toute sa place. Deux approches peuvent alors être conduites pour répondre à cet objectif : 1) la réduction du nombre de traitements et des doses appliquées et 2) le développement…

12 - Feasability study of a wheatears counting system per vision

Working on a feasibility study of wheatears counting, a colour component texture's analysis method was developed. The agronomic goal is yield prediction before harvest evaluating mean number of wheatears per squared meter according to the field variation knowledge. To this counting system, we evaluate six textural parameters (two statistical parameters and four Haralick features from co-occurrence matrix) on the main colour systems and vegetation indices used in agronomic applications. A new hybrid system provides a representation of wheatears' pictures taken under natural conditions with a better extraction of wheat. A method based on distances measurements (Euclidian, Mahalanobis) allows …

Early detection of disease on leaves by image processing

Measurement of the motion of fertilizer particles leaving a centrifugal spreader using a fast imaging system

International audience; Although mechanically simple, centrifugal spreaders used for meneral fertilization involve complex physics that cannot be fully characterized at the present time. We are developing sensors to evaluate the spatial distribution of the fertilizer on the ground based on the measurement of initial flight conditions of fertilizer granules after their ejection by the spreading disk. The techniques developed are based on the analysis of images of the area around the disk showing the granule ejection. A high resolution - low cost imaging system for the analysis of high speed particle projection developed for this specific purpose is presented in this paper. The system, based …

Jugement de la couleur des carcasses en abattoir. Eléments d’objectivation de la notation experte de la couleur des viandes de gros bovins Charolais

Evaluation of carcass color at the slaughterhouse Expert notation is the reference method for the evaluation of bovine meat color, notably for quality. A total of 140 Charolais carcasses were scored at the slaughterhouse on a color scale going from 1 (too light) to 5 (too dark). These expert scores were compared to three types of instrumental data (L*a*b / RVB referential; image shooting with image processing / chromameter). Amongst the instrumental measurements, the values obtained after image processing of the whole muscle seems to be better associated with the scores obtained for color by experts than the scores obtained with the chromameter for which the zone of the muscle analyzed is m…

Leaf surface roughness characterization by image processing

International audience

Statistical methods for texture analysis applied to agronomical images

For activities of agronomical research institute, the land experimentations are essential and provide relevant information on crops such as disease rate, yield components, weed rate... Generally accurate, they are manually done and present numerous drawbacks, such as penibility, notably for wheat ear counting. In this case, the use of color and/or texture image processing to estimate the number of ears per square metre can be an improvement. Then, different image segmentation techniques based on feature extraction have been tested using textural information with first and higher order statistical methods. The Run Length method gives the best results closed to manual countings with an averag…

Roughness evaluation of vine leaf by image processing

International audience; The study of leaf surface roughness is very important in the domain of precision spraying. It is one of the parameters that allow to reduce costs and losses of phytosanitary prod- ucts and to improve the spray accuracy. Moreover, the leaf roughness is related to adhesion mechanisms of liquid on a surface. It can be used to define leaf nature surface (hy- drophilic/hydrophobic). The main goal of this study is thus to estimate and to follow the evolution of leaf roughness using image processing and computer vision. The develop- ment and application of computer vision for measurement of surface leaf roughness using artificial neural networks will be described. The syste…

Vine leaf roughness estimation by image processing

International audience; The application of plant protection product has an important role in agricultural production processes. With current pesticides management, a huge amount of them are applied to worldwide orchards. In precision spraying, spray application efficiency depends on the pesticide application method, the phytosanitary product as well as the leaf surface properties. For environmental and economic reasons, the global trend is to reduce the pesticide application rate of the few approved active substances. Under these constraints, one of the challenges is to improve the efficiency of pesticide application. Different parameters can influence pesticide application such as nozzle t…

A 3-D simulation with virtual stereo rig for centrifugal fertilizer spreading

International audience; Stereovision can be used to characterize of the fertilizer centrifugal spreading process and to control the spreading fertilizer distribution pattern on the ground reference. Fertilizer grains, however, resemble each other and the grain images contain little information on texture. Therefore, the accuracy of stereo matching algorithms in literature cannot be used as a reference for stereo images of fertilizer grains. In order to evaluate stereo matching algorithms applied to images of grains a generator of synthetic stereo particle images is presented in this paper. The particle stereo image generator consists of two main parts: the particle 3D position generator and…

Variable rate fertilisation: Measurement of fertilizer granules motion on a centrifugal spreader by image analysis

Although mechanically simple, centrifugal spreaders used for mineral fertilization involve complexphysics that cannot be fully characterized at the present time. We are developing sensors to evaluatethe spatial distribution of the fertilizer on the ground based on the measurement of initial flightconditions of fertilizer granules after their ejection by the spreading disk. The techniques developedare based on the analysis of images of the area around the disk showing the granule ejection. A fastimaging technique developed for this specific purpose is presented in this paper. It allows toautomatically compute the direction of ejection and velocity of each granule observed in the image.

Optimizing Hough transform for fertilizer spreading optical control

International audience; In Europe, centrifugal spreading is a widely used method for agricultural soil fertilization. In this broadcasting method, fertilizer particles fall onto a spinning disk, are accelerated by a vane, and afterward are ejected into the field. To predict and control the spread pattern, a low-cost, embeddable technology adapted to farm implements must be developed. We focus on obtaining the velocity and the direction of fertilizer granules when they begin their flight by means of a simple imaging system. We first show that the outlet angle of the vane is a bounded value and that its measurement provides the outlet velocity of the particle. Consequently, a simple camera un…

Texture Classification with Generalized Fourier Descriptors in Dimensionality Reduction Context: An Overview Exploration

In the context of texture classification, this article explores the capacity and the performance of some combinations of feature extraction, linear and nonlinear dimensionality reduction techniques and several kinds of classification methods. The performances are evaluated and compared in term of classification error. In order to test our texture classification protocol, the experiment carried out images from two different sources, the well known Brodatz database and our leaf texture images database.

Texture analysis with statistical methods for wheat ear extraction

In agronomic domain, the simplification of crop counting, necessary for yield prediction and agronomic studies, is an important project for technical institutes such as Arvalis. Although the main objective of our global project is to conceive a mobile robot for natural image acquisition directly in a field, Arvalis has proposed us first to detect by image processing the number of wheat ears in images before to count them, which will allow to obtain the first component of the yield. In this paper we compare different texture image segmentation techniques based on feature extraction by first and higher order statistical methods which have been applied on our images. The extracted features are…

Mesure de netteté basée sur les descripteurs généralisés de Fourier appliquée à la reconstruction 3D par Shape from Focus

National audience; L'étape principale de la méthode de reconstruction 3D " Shape from Focus " est l'utilisation d'un opérateur de mesure de netteté de chaque pixel de la séquence d'image. Le choix de l'opérateur de mesure de netteté est une étape cruciale pour une reconstruction 3D de qualité. La précision de la mesure de netteté dépend de la taille du voisinage autour du pixel choisi et de la présence ou non de bruit additif dans la séquence d'images. Dans cet article, nous présentons deux nouveaux opérateurs de mesure de netteté basés sur les Descripteurs Généralisés de Fourier. Une nouvelle étude comparative des différents opérateurs est présentée. Cette comparaison est basée sur un plan…

Centrifugal spreading : motion blurred images to determine the three components of fertiliser outlet velocity

In the optical control of centrifugal spreading, the use of a single CCD camera to measure the outlet velocity is not limited to flat discs and 2D motion estimation. Combining the kinetic study of the fertiliser motion on the vane and the geometric analysis of image acquisition, the 3D components of the outlet velocity can be deduced from motion blurred images in the case of a traditional concave disc. The estimation of the horizontal and vertical outlet velocities is useful to predict spread patterns using ballistic flight models. This opens up the possibility to implement simple spreader test tools for quality diagnoses or sensors for feedback loop adjustments.

Two-step cross correlation-based algorithm for motion estimation applied to fertilizer granules' motion during centrifugal spreading

Imaging systems are progressing in both accuracy and ro- bustness, and their use in precision agriculture is increasing accordingly. One application of imaging systems is to understand and control the cen- trifugal fertilizing spreading process. Predicting the spreading pattern on the ground relies on an estimation of the trajectories and velocities of ejected granules. The algorithms proposed to date have shown low ac- curacy, with an error rate of a few pixels. But a more accurate estimation of the motion of the granules can be achieved. Our new two-step cross- correlation-based algorithm is based on the technique used in particle image velocimetry (PIV), which has yielded highly accurate…

Système de prise d'images haute résolution pour l'analyse de projection de particules : application à l'épandage centrifuge d'engrais

This paper describes the design of a high resolution low cost imaging system for the analysis of high speed particle projection. This system, based on a camera and a set of flashes, is used to characterize the centrifugal spreading of fertilizer particles ejected at speeds of environ 30 m s. Multiexposure images collected with the camera installed perpendicular to the output flow of granules are analysed to estimate the trajectories of the fertilizer granules. Very good results are obtained with the Markov random fields method, in comparison with others.

Autonomous phenotyping using a mobile manipulator

International audience

European and French level of study correspondence in ABE domain

Biosystems Engineering (BE) term is a reference one in the USA and the UE, with sometimes very different definitions, used since more than a decade. Its contours and contents, for L and M degrees, have been studied in a European program for standardization inside the ERABEE network, allowing to designate this domain as a field of engineering which integrates engineering science and design with applied biological, environmental and agricultural sciences. Therefore, Biosystems Engineering is 'the branch of engineering that applies engineering sciences to solve problems involving biological systems ». This definition appeals to many skills and it is useful to mention that in France, the L1 and…

Détermination de la texture de la feuille de vigne par imagerie

National audience; Dans le contexte de la pulvérisation de précision, nombreuses sont les recherches menées sur l'optimisation d'utilisation des produits phytosanitaires. L'objectif final étant de réduire de manière significative la quantité d'intrant dans les cultures . Dans ce cadre, les travaux présentés dans cet article s'intéresse particulièrement à l'analyse de l'état de surface foliaire qui présente une part essentielle dans le processus d'adhésion du produit pulvérisé sur la feuille. L'analyse de surface de la feuille est réalisée à travers l'analyse des caractéristiques texturale extraites d'images microscopics. Afin de discriminer les différents cépages et âges des feuilles retenu…

Vineyard leaf roughness characterization by computer vision and cloud computing technics

International audience; In the context of vineyard leaf roughness analysis for precision spraying applications, this article deals with its characterization by computer vision and cloud computing techniques. The techniques merge feature extraction, linear or nonlinear dimensionality reduction techniques and several kinds of classification methods. Different combinations are processed and their performances compared in terms of classification error rate, in order to find the best association. However these combinations are hardly processed because of the lack of computing power and the prohibitive time consumption of the algorithms. To overcome these difficulties, we propose a solution: the …

A new tool for assessment of biostimulants effects on grapevine

National audience; Despite an increasing interest for the use of biostimulants (BS) in agriculture, methods allowing a precise description of their effects on plants remain rather limited. In the IRIS+ FUI project, two major and highly different worldwide crops, wheat (annual, monocotyledon) and grapevine (perennial, broadleaf) were chosen to deepen our knowledge of such compounds and explore their potential additional interest. One objective was to develop a tool adapted to the screening and study of the impact of a series of BS on the development and physiology of these crops in controlled conditions. We managed to develop such a tool adapted to grapevine herbaceous cuttings. It allows a …

Graph-based denoising of skeletonized root-systems

Special Issue "Remote Sensing and Proximal Sensing in Support of Agricultural Cultivation and Crop Risk Management"

prod 2019-108 équipe BAP équipe EA GEAPSI AGROSUP

Motion coordination of a mobile manipulator within control framework: application to phenotyping

Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles

International audience; Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective …

Remote and proximal sensing for precision agriculture and viticulture". Special issue

International audience; Special Issue InformationDear Colleagues,Remote and proximal sensing are the two most common techniques concerning the acquisition of information about an object or any phenomenon without physical contact with the object. Remote sensing is widely tied to the use of satellite, airborne or UAV platforms using multi- or hyperspectral imagery. In terms of proximal sensing, the sensor is close to the object and is installed on platforms ranging from handheld, fixed installations, or robotics and tractor-embedded sensors. The types of sensors range from simple RGB or grey-level-cameras to multispectral and hyperspectral high resoluted imaging systems or even thermographic …

Predicting spread patterns of centrifugal fertiliser spreaders

International audience; Nowadays farmers recognize the importance of a correct and precise fertiliser application: non-uniform spread patterns cause extra pressure on the environment and might result in economic losses for the farmer. In Europe most spreading is done by centrifugal fertilizer spreaders but their spreading process is not easy to monitor and to control. To perform a precise fertilising farmers need proper tools to determine and evaluate the spread pattern at farm level. Therefore the Flemish Institute for Agricultural and Fisheries Research (ILVO) is exploring and developing a fast and accurate technique for measuring the spread pattern of conventional centrifugal spreaders. …

Feasibility of selecting optimal textural features to detect foliar symptoms of ‘flavescence doree’ grapevine disease

3D ACQUISITION SYSTEM APPLIED TO AGRONOMIC SCENES

International audience; To improve results in automatic wheat ear counting by proxy-detection for early yield prediction, we need depth information of the scene. In this paper, we describe our 3D acquisition system dedicated to reconstruction of agronomic scenes. This system is composed of a camera mounted on a linear displacement driven by a microcontroller. The linear displacement allows acquiring a set of images in different distances to the scene. This image stack is used to apply shape from focus technique which is a passive and monocular 3D reconstruction method. This technique consists in the application of a focus measure for every pixel in the stack. An approximation method is used…

Associer biostimulants, SDP, systèmes d’imagerie et de pulvérisation au service de la santé du vignoble

Prod?IPMGEAPSISPEEAINRAUBAGROSUPDOCT; Associer biostimulants, SDP, systèmes d’imagerie et de pulvérisation au service de la santé du vignoble

High resolution imagery for phenotypic root traits detection

AgrosupINRAEAGEAPSI; High resolution imagery for phenotypic root traits detection. CIRG-AgEng 2016, International Conférence on Agricultural Engineering, Automation, Environment and Food Safety

Spray droplet characteristics measured using high speed imaging techniques

Presented at Conference International Advances in Pesticide Application (IAPA), Barcelone, ESP (2016-01-13 - 2016-01-15).; International audience; Spray droplet characteristics are important features of an agricultural spray. The objective of this study is to measure the droplet size for different types of hydraulic spray nozzles using a developed backlighted image acquisition system and image processing technique. An in-focus droplet criterion was established to decide whether a droplet is in focus and can be measured in an accurate way. Tests included five different nozzles (Albuz ATR orange and red, TeeJet XR 110 01, XR 110 04 and Al 110 04).

Biocontrôle et pulvérisation

In situ Phenotyping of Grapevine Root System Architecture by 2D or 3D Imaging: Advantages and Limits of Three Cultivation Methods

International audience; The root system plays an essential role in the development and physiology of the plant, as well as in its response to various stresses. However, it is often insufficiently studied, mainly because it is difficult to visualize. For grapevine, a plant of major economic interest, there is a growing need to study the root system, in particular to assess its resistance to biotic and abiotic stresses, understand the decline that may affect it, and identify new ecofriendly production systems. In this context, we have evaluated and compared three distinct growing methods (hydroponics, plane, and cylindric rhizotrons) in order to describe relevant architectural root traits of …