Automatic segmentation of relevant textures in agricultural images

One important issue emerging strongly in agriculture is related with the automatization of tasks, where the optical sensors play an important role. They provide images that must be conveniently processed. The most relevantimage processing procedures require the identification of green plants, in our experiments they come from barley and corn crops including weeds, so that some types of action can be carried out, including site-specific treatments with chemical products or mechanical manipulations. Also the identification of textures belonging to the soil could be useful to know some variables, such as humidity, smoothness or any others. Finally, from the point of view of the autonomous robot navigation, where the robot is equipped with the imaging system, some times it is convenient to know not only the soil information and the plants growing in the soil but also additional information supplied by global references based on specific areas. This implies that the images to be processed contain textures of three main types to be identified: green plants, soil and sky if any. This paper proposes a new automatic approach for segmenting these main textures and also to refine the identification of sub-textures inside the main ones. Concerning the green identification, we propose a new approach that exploits the performance of existing strategies by combining them. The combination takes into account the relevance of the information provided by each strategy based on the intensity variability. This makes an important contribution. The combination of thresholding approaches, for segmenting the soil and the sky, makes the second contribution; finally the adjusting of the supervised fuzzy clustering approach for identifying sub-textures automatically, makes the third finding. The performance of the method allows to verify its viability for automatic tasks in agriculture based on image processin

Development of Enhanced Weed Detection System with Adaptive Thresholding, K-Means and Support Vector Machine

This paper proposes a sophisticated classification process to segment the leaves of carrots from weeds (mostly Chamomile). In the early stages, of the plants’ development, both weeds and carrot leaves are intermixed with each other and have similar color texture. This makes it difficult to identify without the help of the domain experts. Therefore, it is essential to remove the weed regions so that the carrot plants can grow without any interruptions. The process of identifying the weeds become more challenging when both plant and weed regions overlap (inter-leaves). The proposed system addresses this problem by creating a sophisticated means for weed identification. The major components of this system are composed of three processes: Image Segmentation, Feature Extraction, and Decision-Making. In the Image Segmentation process, the input images are processed into lower units where the relevant features are extracted. In the second proposed method, K-Means clustering is applied to extract the images that will be used for the identification process. The images are then normalized into a binary image using Otsu’s Thresholding. Next, in the Feature Extraction stage, relevant information of the weed and leaves are extracted from the lower unit images. Furthermore, to extract the information from the Region of Interest (ROI), Histogram of Oriented Gradient (HoG) is used to locate and label all the weed and carrot leaves regions. In the Decision-Making process, the system makes use of Support Vector Machine (SVM), which is a supervised learning algorithm, is used to analyze and segregate the weeds from the plants. Afterward, the findings are used to dictate which plants receive herbicides and which do not. The main priority for the Image Segmentation process is on overlapping images where weeds need to be isolated from plants; otherwise, in the later stages, those plants cannot be used for cultivation purposes. These methods of weed detection are effective as it automates the identification process and fewer herbicides will be used, which in turn is beneficial to the environment. The evaluation of the approach was done using an open dataset of images consisting of carrot plants. The system was able to achieve 88.99% accuracy for weed classification using this dataset. Further improvement of the proposed method successfully classifies the plant regions at a success rate of 92%. These methodologies will help reduce the use of herbicides while improving the performance and costs of Precision Agriculture

A survey of image processing techniques for agriculture

Computer technologies have been shown to improve agricultural productivity in a number of ways. One technique which is emerging as a useful tool is image processing. This paper presents a short survey on using image processing techniques to assist researchers and farmers to improve agricultural practices. Image processing has been used to assist with precision agriculture practices, weed and herbicide technologies, monitoring plant growth and plant nutrition management. This paper highlights the future potential for image processing for different agricultural industry contexts

Automatic expert system based on images for accuracy crop row detection in maize fields

This paper proposes an automatic expert system for accuracy crop row detection in maize fields based on images acquired from a vision system. Different applications in maize, particularly those based on site specific treatments, require the identification of the crop rows. The vision system is designed with a defined geometry and installed onboard a mobile agricultural vehicle, i.e. submitted to vibrations, gyros or uncontrolled movements. Crop rows can be estimated by applying geometrical parameters under image perspective projection. Because of the above undesired effects, most often, the estimation results inaccurate as compared to the real crop rows. The proposed expert system exploits the human knowledge which is mapped into two modules based on image processing techniques. The first one is intended for separating green plants (crops and weeds) from the rest (soil, stones and others). The second one is based on the system geometry where the expected crop lines are mapped onto the image and then a correction is applied through the well-tested and robust Theil–Sen estimator in order to adjust them to the real ones. Its performance is favorably compared against the classical Pearson product–moment correlation coefficient

Improving field management by machine vision - a review

Growing population of people around the world and thus increasing demand to food products as well as high tendency for declining the cost of operations and environmental preserving cares intensify inclination toward the application of variable rate systems for agricultural treatments, in which machine vision as a powerful appliance has been paid vast attention by agricultural researchers and farmers as this technology consumers. Various applications have introduced for machine vision in different fields of agricultural and food industry till now that confirms the high potential of this approach for inspection of different parameters affecting productivity. Computer vision has been utilized for quantification of factors affecting crop growth in field; such as, weed, irrigation, soil quality, plant nutrients and fertilizers in several cases. This paper presents some of these successful applications in addition to representing an introduction to machine vision

Camera sensor arrangement for crop/weed detection accuracy in agronomic images

In Precision Agriculture, images coming from camera-based sensors are commonly used for weed identification and crop line detection, either to apply specific treatments or for vehicle guidance purposes. Accuracy of identification and detection is an important issue to be addressed in image processing. There are two main types of parameters affecting the accuracy of the images, namely: (a) extrinsic, related to the sensor's positioning in the tractor; (b) intrinsic, related to the sensor specifications, such as CCD resolution, focal length or iris aperture, among others. Moreover, in agricultural applications, the uncontrolled illumination, existing in outdoor environments, is also an important factor affecting the image accuracy. This paper is exclusively focused on two main issues, always with the goal to achieve the highest image accuracy in Precision Agriculture applications, making the following two main contributions: (a) camera sensor arrangement, to adjust extrinsic parameters and (b) design of strategies for controlling the adverse illumination effects. © 2013 by the authors; licensee MDPI, Basel, Switzerland.The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement NO.245986. This paper has been extended from a previous paper published in [20]. The authors wish also to acknowledge to the project AGL2011-30442-C02-02, supported by the Ministerio de Economía y Competitividad of Spain within the Plan Nacional de I+D+i.Peer Reviewe

Automatic detection of crop rows in maize fields with high weeds pressure

This paper proposes a new method, oriented to crop row detection in images from maize fields with high weed pressure. The vision system is designed to be installed onboard a mobile agricultural vehicle, i.e. submitted to gyros, vibrations and undesired movements. The images are captured under image perspective, being affected by the above undesired effects. The image processing consists of three main processes: image segmentation, double thresholding, based on the Otsu’s method, and crop row detection. Image segmentation is based on the application of a vegetation index, the double thresholding achieves the separation between weeds and crops and the crop row detection applies least squares linear regression for line adjustment. Crop and weed separation becomes effective and the crop row detection can be favorably compared against the classical approach based on the Hough transform. Both gain effectiveness and accuracy thanks to the double thresholding that makes the main finding of the paper

Técnicas de visión por computador para la detección del verdor y la detección de obstáculos en campos de maíz

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de Ingeniería del Software e Inteligencia Artificial, leída el 22/06/2017There is an increasing demand in the use of Computer Vision techniques in Precision Agriculture (PA) based on images captured with cameras on-board autonomous vehicles. Two techniques have been developed in this research. The rst for greenness identi cation and the second for obstacle detection in maize elds, including people and animals, for tractors in the RHEA (robot eets for highly e ective and forestry management) project, equipped with monocular cameras on-board the tractors. For vegetation identi cation in agricultural images the combination of colour vegetation indices (CVIs) with thresholding techniques is the usual strategy where the remaining elements on the image are also extracted. The main goal of this research line is the development of an alternative strategy for vegetation detection. To achieve our goal, we propose a methodology based on two well-known techniques in computer vision: Bag of Words representation (BoW) and Support Vector Machines (SVM). Then, each image is partitioned into several Regions Of Interest (ROIs). Afterwards, a feature descriptor is obtained for each ROI, then the descriptor is evaluated with a classi er model (previously trained to discriminate between vegetation and background) to determine whether or not the ROI is vegetation...Cada vez existe mayor demanda en el uso de t ecnicas de Visi on por Computador en Agricultura de Precisi on mediante el procesamiento de im agenes captadas por c amaras instaladas en veh culos aut onomos. En este trabajo de investigaci on se han desarrollado dos tipos de t ecnicas. Una para la identi caci on de plantas verdes y otra para la detecci on de obst aculos en campos de ma z, incluyendo personas y animales, para tractores del proyecto RHEA. El objetivo nal de los veh culos aut onomos fue la identi caci on y eliminaci on de malas hierbas en los campos de ma z. En im agenes agr colas la vegetaci on se detecta generalmente mediante ndices de vegetaci on y m etodos de umbralizaci on. Los ndices se calculan a partir de las propiedades espectrales en las im agenes de color. En esta tesis se propone un nuevo m etodo con tal n, lo que constituye un objetivo primordial de la investigaci on. La propuesta se basa en una estrategia conocida como \bolsa de palabras" conjuntamente con un modelo se aprendizaje supervisado. Ambas t ecnicas son ampliamente utilizadas en reconocimiento y clasi caci on de im agenes. La imagen se divide inicialmente en regiones homog eneas o de inter es (RIs). Dada una colecci on de RIs, obtenida de un conjunto de im agenes agr colas, se calculan sus caracter sticas locales que se agrupan por su similitud. Cada grupo representa una \palabra visual", y el conjunto de palabras visuales encontradas forman un \diccionario visual". Cada RI se representa por un conjunto de palabras visuales las cuales se cuanti can de acuerdo a su ocurrencia dentro de la regi on obteniendo as un vector-c odigo o \codebook", que es descriptor de la RI. Finalmente, se usan las M aquinas de Vectores Soporte para evaluar los vectores-c odigo y as , discriminar entre RIs que son vegetaci on del resto...Depto. de Ingeniería de Software e Inteligencia Artificial (ISIA)Fac. de InformáticaTRUEunpu

A new expert system for greenness identification in agricultural images

It is well-known that one important issue emerging strongly in agriculture is related with the automation of tasks, where camera-based sensors play an important role. They provide images that must be conveniently processed. The most relevant image processing procedures require the identification of green plants, in our experiments they comes from barley and maize fields including weeds, so that some type of action can be carried out, including site-specific treatments with chemical products or mechanical manipulations. The images come from outdoor environments, which are affected for a high variability of illumination conditions because of sunny or cloudy days or both with high rate of changes. Several indices have been proposed in the literature for greenness identification, but under adverse environmental conditions most of them fail or do not work properly. This is true even for camera devices with auto-image white balance. This paper proposes a new automatic and robust Expert System for greenness identification. It consists of two main modules: (1) decision making, based on image histogram analysis and (2) greenness identification, where two different strategies are proposed, the first based on classical greenness identification methods and the second inspired on the Fuzzy Clustering approach. The Expert System design as a whole makes a contribution, but the Fuzzy Clustering strategy makes the main finding of this paper. The system is tested for different images captured with several camera devices. (C) 2012 Elsevier Ltd. All rights reserved

DeepWheat: Estimating Phenotypic Traits from Crop Images with Deep Learning

In this paper, we investigate estimating emergence and biomass traits from color images and elevation maps of wheat field plots. We employ a state-of-the-art deconvolutional network for segmentation and convolutional architectures, with residual and Inception-like layers, to estimate traits via high dimensional nonlinear regression. Evaluation was performed on two different species of wheat, grown in field plots for an experimental plant breeding study. Our framework achieves satisfactory performance with mean and standard deviation of absolute difference of 1.05 and 1.40 counts for emergence and 1.45 and 2.05 for biomass estimation. Our results for counting wheat plants from field images are better than the accuracy reported for the similar, but arguably less difficult, task of counting leaves from indoor images of rosette plants. Our results for biomass estimation, even with a very small dataset, improve upon all previously proposed approaches in the literature.Comment: WACV 2018 (Code repository: https://github.com/p2irc/deepwheat_WACV-2018