Edge detection for weed recognition in lawns

[EN] The rapid propagation of weeds is a major issue for turfgrass management (both ornamental and sports turf). While pesticides can ensure weed eradication, they pose a risk to human health and the environment. In this context, the early detection of weeds can allow a dramatic reduction in the amount of pesticide required. Here we present the use of edge detection techniques to identify the presence of these invasive plants in ornamental lawns and sports turf. Regarding the former, images from small experimental plots in the facilities of IMIDRA were used while images for the latter were taken on a golf course. Up to 12 different filters for edge detection were tested on the images collected. Aggregation techniques, with a range of cell values, were applied to the results of the three most effective filters (sharpening (I), sharpening (II), and Laplacian) to minimise the number of false positives. After the tests with different cell sizes, two filters were selected for more in-depth analysis. Box plots were selected to define the best cell size and identify the filter with the best performance. The sharpening (I) filter and the aggregation technique with the minimum value and a cell size of 10 offered the best results. Finally, we determined the most appropriate threshold value on the basis of the number of false positives, false negatives, and derived indexes (Precision, Recall, and F1-Score). A threshold of 78 gave the best performance. The results achieved with this methodology differed slightly between ornamental and sports turf.This work was partially funded by the Conselleria de Educacion, Cultura y Deporte through "Subvenciones para la contratacion de personal investigador en fase postdoctoral", grant number APOSTD/2019/04, by the European Union through ERANETMED (Euromediterranean Cooperation through ERANET joint activities and beyond) project ERANETMED3-227 SMARTWATIR, and by the European Union with the "Fondo Europeo Agricola de Desarrollo Rural (ERDF) - Europa invierte en zonas rurales", the MAPAMA, and Comunidad de Madrid with the IMIDRA, through the "PDR-CM 2014-2020" project number PDR18-XEROCESPED.Parra, L.; Marin, J.; Yousfi, S.; Rincón, G.; Mauri Ablanque, PV.; Lloret, J. (2020). Edge detection for weed recognition in lawns. Computers and Electronics in Agriculture. 176:1-13. https://doi.org/10.1016/j.compag.2020.10568411317

Improving the maize crop row navigation line recognition method of YOLOX

The accurate identification of maize crop row navigation lines is crucial for the navigation of intelligent weeding machinery, yet it faces significant challenges due to lighting variations and complex environments. This study proposes an optimized version of the YOLOX-Tiny single-stage detection network model for accurately identifying maize crop row navigation lines. It incorporates adaptive illumination adjustment and multi-scale prediction to enhance dense target detection. Visual attention mechanisms, including Efficient Channel Attention and Cooperative Attention modules, are introduced to better extract maize features. A Fast Spatial Pyramid Pooling module is incorporated to improve target localization accuracy. The Coordinate Intersection over Union loss function is used to further enhance detection accuracy. Experimental results demonstrate that the improved YOLOX-Tiny model achieves an average precision of 92.2 %, with a detection time of 15.6 milliseconds. This represents a 16.4 % improvement over the original model while maintaining high accuracy. The proposed model has a reduced size of 18.6 MB, representing a 7.1 % reduction. It also incorporates the least squares method for accurately fitting crop rows. The model showcases efficiency in processing large amounts of data, achieving a comprehensive fitting time of 42 milliseconds and an average angular error of 0.59°. The improved YOLOX-Tiny model offers substantial support for the navigation of intelligent weeding machinery in practical applications, contributing to increased agricultural productivity and reduced usage of chemical herbicides

Weed Classification for Site-Specific Weed Management Using an Automated Stereo Computer-Vision Machine-Learning System in Rice Fields

Producción CientíficaSite-specific weed management and selective application of herbicides as eco-friendly techniques are still challenging tasks to perform, especially for densely cultivated crops, such as rice. This study is aimed at developing a stereo vision system for distinguishing between rice plants and weeds and further discriminating two types of weeds in a rice field by using artificial neural networks (ANNs) and two metaheuristic algorithms. For this purpose, stereo videos were recorded across the rice field and different channels were extracted and decomposed into the constituent frames. Next, upon pre-processing and segmentation of the frames, green plants were extracted out of the background. For accurate discrimination of the rice and weeds, a total of 302 color, shape, and texture features were identified. Two metaheuristic algorithms, namely particle swarm optimization (PSO) and the bee algorithm (BA), were used to optimize the neural network for selecting the most effective features and classifying different types of weeds, respectively. Comparing the proposed classification method with the K-nearest neighbors (KNN) classifier, it was found that the proposed ANN-BA classifier reached accuracies of 88.74% and 87.96% for right and left channels, respectively, over the test set. Taking into account either the arithmetic or the geometric means as the basis, the accuracies were increased up to 92.02% and 90.7%, respectively, over the test set. On the other hand, the KNN suffered from more cases of misclassification, as compared to the proposed ANN-BA classifier, generating an overall accuracy of 76.62% and 85.59% for the classification of the right and left channel data, respectively, and 85.84% and 84.07% for the arithmetic and geometric mean values, respectively

Optimized Deep Learning Model as a Basis for Fast UAV Mapping of Weed Species in Winter Wheat Crops

Weed maps should be available quickly, reliably, and with high detail to be useful for site-specific management in crop protection and to promote more sustainable agriculture by reducing pesticide use. Here, the optimization of a deep residual convolutional neural network (ResNet-18) for the classification of weed and crop plants in UAV imagery is proposed. The target was to reach sufficient performance on an embedded system by maintaining the same features of the ResNet-18 model as a basis for fast UAV mapping. This would enable online recognition and subsequent mapping of weeds during UAV flying operation. Optimization was achieved mainly by avoiding redundant computations that arise when a classification model is applied on overlapping tiles in a larger input image. The model was trained and tested with imagery obtained from a UAV flight campaign at low altitude over a winter wheat field, and classification was performed on species level with the weed species Matricaria chamomilla L., Papaver rhoeas L., Veronica hederifolia L., and Viola arvensis ssp. arvensis observed in that field. The ResNet-18 model with the optimized image-level prediction pipeline reached a performance of 2.2 frames per second with an NVIDIA Jetson AGX Xavier on the full resolution UAV image, which would amount to about 1.78 ha h−1 area output for continuous field mapping. The overall accuracy for determining crop, soil, and weed species was 94%. There were some limitations in the detection of species unknown to the model. When shifting from 16-bit to 32-bit model precision, no improvement in classification accuracy was observed, but a strong decline in speed performance, especially when a higher number of filters was used in the ResNet-18 model. Future work should be directed towards the integration of the mapping process on UAV platforms, guiding UAVs autonomously for mapping purpose, and ensuring the transferability of the models to other crop fields

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 Comprehensive Survey of Deep Learning in Remote Sensing: Theories, Tools and Challenges for the Community

In recent years, deep learning (DL), a re-branding of neural networks (NNs), has risen to the top in numerous areas, namely computer vision (CV), speech recognition, natural language processing, etc. Whereas remote sensing (RS) possesses a number of unique challenges, primarily related to sensors and applications, inevitably RS draws from many of the same theories as CV; e.g., statistics, fusion, and machine learning, to name a few. This means that the RS community should be aware of, if not at the leading edge of, of advancements like DL. Herein, we provide the most comprehensive survey of state-of-the-art RS DL research. We also review recent new developments in the DL field that can be used in DL for RS. Namely, we focus on theories, tools and challenges for the RS community. Specifically, we focus on unsolved challenges and opportunities as it relates to (i) inadequate data sets, (ii) human-understandable solutions for modelling physical phenomena, (iii) Big Data, (iv) non-traditional heterogeneous data sources, (v) DL architectures and learning algorithms for spectral, spatial and temporal data, (vi) transfer learning, (vii) an improved theoretical understanding of DL systems, (viii) high barriers to entry, and (ix) training and optimizing the DL.Comment: 64 pages, 411 references. To appear in Journal of Applied Remote Sensin

Pose-invariant face recognition using real and virtual views

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (p. 173-184).by David James Beymer.Ph.D

Development of a smart weed detector and selective herbicide sprayer

Abstract: The fourth industrial revolution has brought about tremendous advancements in various sectors of the economy including the agricultural domain. Aimed at improving food production and alleviating poverty, these technological advancements through precision agriculture has ushered in optimized agricultural processes, real-time analysis and monitoring of agricultural data. The detrimental effects of applying agrochemicals in large or hard-to-reach farmlands and the need to treat a specific class of weed with a particular herbicide for effective weed elimination gave rise to the necessity of this research work...M.Ing. (Mechanical Engineering