55 research outputs found
Sea-Surface Object Detection Based on Electro-Optical Sensors: A Review
Sea-surface object detection is critical for navigation safety of autonomous ships. Electrooptical (EO) sensors, such as video cameras, complement radar on board in detecting small obstacle
sea-surface objects. Traditionally, researchers have used horizon detection, background subtraction, and
foreground segmentation techniques to detect sea-surface objects. Recently, deep learning-based object
detection technologies have been gradually applied to sea-surface object detection. This article demonstrates a comprehensive overview of sea-surface object-detection approaches where the advantages
and drawbacks of each technique are compared, covering four essential aspects: EO sensors and image
types, traditional object-detection methods, deep learning methods, and maritime datasets collection. In
particular, sea-surface object detections based on deep learning methods are thoroughly analyzed and
compared with highly influential public datasets introduced as benchmarks to verify the effectiveness of
these approaches. The arti
Automatic vision based fault detection on electricity transmission components using very highresolution
Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial TechnologiesElectricity is indispensable to modern-day governments and citizenry’s day-to-day operations.
Fault identification is one of the most significant bottlenecks faced by Electricity transmission and
distribution utilities in developing countries to deliver credible services to customers and ensure
proper asset audit and management for network optimization and load forecasting. This is due to
data scarcity, asset inaccessibility and insecurity, ground-surveys complexity, untimeliness, and
general human cost. In this context, we exploit the use of oblique drone imagery with a high spatial
resolution to monitor four major Electric power transmission network (EPTN) components
condition through a fine-tuned deep learning approach, i.e., Convolutional Neural Networks
(CNNs). This study explored the capability of the Single Shot Multibox Detector (SSD), a onestage
object detection model on the electric transmission power line imagery to localize, classify
and inspect faults present. The components fault considered include the broken insulator plate,
missing insulator plate, missing knob, and rusty clamp. The adopted network used a CNN based
on a multiscale layer feature pyramid network (FPN) using aerial image patches and ground truth
to localise and detect faults via a one-phase procedure. The SSD Rest50 architecture variation
performed the best with a mean Average Precision of 89.61%. All the developed SSD based
models achieve a high precision rate and low recall rate in detecting the faulty components, thus
achieving acceptable balance levels F1-score and representation. Finally, comparable to other
works of literature within this same domain, deep-learning will boost timeliness of EPTN inspection
and their component fault mapping in the long - run if these deep learning architectures are widely
understood, adequate training samples exist to represent multiple fault characteristics; and the
effects of augmenting available datasets, balancing intra-class heterogeneity, and small-scale
datasets are clearly understood
Oriented Object Detection in Optical Remote Sensing Images using Deep Learning: A Survey
Oriented object detection is one of the most fundamental and challenging
tasks in remote sensing, aiming at locating the oriented objects of numerous
predefined object categories. Recently, deep learning based methods have
achieved remarkable performance in detecting oriented objects in optical remote
sensing imagery. However, a thorough review of the literature in remote sensing
has not yet emerged. Therefore, we give a comprehensive survey of recent
advances and cover many aspects of oriented object detection, including problem
definition, commonly used datasets, evaluation protocols, detection frameworks,
oriented object representations, and feature representations. Besides, the
state-of-the-art methods are analyzed and discussed. We finally discuss future
research directions to put forward some useful research guidance. We believe
that this survey shall be valuable to researchers across academia and industr
A Survey of Deep Learning-Based Object Detection
Object detection is one of the most important and challenging branches of
computer vision, which has been widely applied in peoples life, such as
monitoring security, autonomous driving and so on, with the purpose of locating
instances of semantic objects of a certain class. With the rapid development of
deep learning networks for detection tasks, the performance of object detectors
has been greatly improved. In order to understand the main development status
of object detection pipeline, thoroughly and deeply, in this survey, we first
analyze the methods of existing typical detection models and describe the
benchmark datasets. Afterwards and primarily, we provide a comprehensive
overview of a variety of object detection methods in a systematic manner,
covering the one-stage and two-stage detectors. Moreover, we list the
traditional and new applications. Some representative branches of object
detection are analyzed as well. Finally, we discuss the architecture of
exploiting these object detection methods to build an effective and efficient
system and point out a set of development trends to better follow the
state-of-the-art algorithms and further research.Comment: 30 pages,12 figure
Collision Avoidance on Unmanned Aerial Vehicles using Deep Neural Networks
Unmanned Aerial Vehicles (UAVs), although hardly a new technology, have recently
gained a prominent role in many industries, being widely used not only among enthusiastic
consumers but also in high demanding professional situations, and will have a
massive societal impact over the coming years. However, the operation of UAVs is full
of serious safety risks, such as collisions with dynamic obstacles (birds, other UAVs, or
randomly thrown objects). These collision scenarios are complex to analyze in real-time,
sometimes being computationally impossible to solve with existing State of the Art (SoA)
algorithms, making the use of UAVs an operational hazard and therefore significantly reducing
their commercial applicability in urban environments. In this work, a conceptual
framework for both stand-alone and swarm (networked) UAVs is introduced, focusing on
the architectural requirements of the collision avoidance subsystem to achieve acceptable
levels of safety and reliability. First, the SoA principles for collision avoidance against
stationary objects are reviewed. Afterward, a novel image processing approach that uses
deep learning and optical flow is presented. This approach is capable of detecting and
generating escape trajectories against potential collisions with dynamic objects. Finally,
novel models and algorithms combinations were tested, providing a new approach for
the collision avoidance of UAVs using Deep Neural Networks. The feasibility of the proposed
approach was demonstrated through experimental tests using a UAV, created from
scratch using the framework developed.Os veículos aéreos não tripulados (VANTs), embora dificilmente considerados uma
nova tecnologia, ganharam recentemente um papel de destaque em muitas indústrias,
sendo amplamente utilizados não apenas por amadores, mas também em situações profissionais
de alta exigência, sendo expectável um impacto social massivo nos próximos
anos. No entanto, a operação de VANTs está repleta de sérios riscos de segurança, como
colisões com obstáculos dinâmicos (pássaros, outros VANTs ou objetos arremessados).
Estes cenários de colisão são complexos para analisar em tempo real, às vezes sendo computacionalmente
impossível de resolver com os algoritmos existentes, tornando o uso de
VANTs um risco operacional e, portanto, reduzindo significativamente a sua aplicabilidade
comercial em ambientes citadinos. Neste trabalho, uma arquitectura conceptual
para VANTs autônomos e em rede é apresentada, com foco nos requisitos arquitetônicos
do subsistema de prevenção de colisão para atingir níveis aceitáveis de segurança e confiabilidade.
Os estudos presentes na literatura para prevenção de colisão contra objectos
estacionários são revistos e uma nova abordagem é descrita. Esta tecnica usa técnicas
de aprendizagem profunda e processamento de imagem, para realizar a prevenção de
colisões em tempo real com objetos móveis. Por fim, novos modelos e combinações de algoritmos
são propostos, fornecendo uma nova abordagem para evitar colisões de VANTs
usando Redes Neurais Profundas. A viabilidade da abordagem foi demonstrada através
de testes experimentais utilizando um VANT, desenvolvido a partir da arquitectura
apresentada
Advances in Image Processing, Analysis and Recognition Technology
For many decades, researchers have been trying to make computers’ analysis of images as effective as the system of human vision is. For this purpose, many algorithms and systems have previously been created. The whole process covers various stages, including image processing, representation and recognition. The results of this work can be applied to many computer-assisted areas of everyday life. They improve particular activities and provide handy tools, which are sometimes only for entertainment, but quite often, they significantly increase our safety. In fact, the practical implementation of image processing algorithms is particularly wide. Moreover, the rapid growth of computational complexity and computer efficiency has allowed for the development of more sophisticated and effective algorithms and tools. Although significant progress has been made so far, many issues still remain, resulting in the need for the development of novel approaches
Multi-Modal Earth Observation and Deep Learning for Urban Scene Understanding
This research explores the nuances of semantic segmentation in remote sensing data through deep learning, with a focus on multi-modal data integration, the impact of label noise, and the need for diverse datasets in Earth Observation (EO). It introduces a novel model named TransFusion, designed to integrate 2D images and 3D point clouds directly, avoiding the complexities common with traditional fusion methods used in the conext of semantic segmentation. This approach led to improvements in segmentation accuracy, demonstrated by higher mean Intersection over Union (mIoU) scores for the Vaihingen and Potsdam datasets. This indicates the model's capability to better interpret spatial and structural information from multi-modal data.The study also investigates the effects of label noise—incorrect annotations in training data, a prevalent issue in remote sensing. Through experiments involving high-resolution aerial images with intentionally inaccurate labels, it was discovered that label noise influences model performance differently across various object classes, with the size of an object significantly affecting the model's ability to handle errors. The research highlights that models are somewhat resilient to random noise, although accuracy decreases even with a small proportion of incorrect labels.Addressing the challenge of geographic bias in urban semantic segmentation datasets, primarily focused on Europe and North America, the research introduces the UAVPal dataset from Bhopal, India. This effort, along with the development of a new dense predictor head for semantic segmentation, aims to better represent the diverse urban landscapes globally. The new segmentation head, which efficiently leverages multi-scale features and notably reduces computational demands, showed improved mIoU scores across various classes and datasets.Overall, the study contributes to the field of semantic segmentation for EO by improving data fusion methods, offering insights into the effects of label noise, and encouraging the inclusion of diverse geographic data for broader representation. These efforts are steps toward more accurate and efficient remote sensing applications
A Non-Reference Evaluation of Underwater Image Enhancement Methods Using a New Underwater Image Dataset
The rise of vision-based environmental, marine, and oceanic exploration research highlights the need for supporting underwater image enhancement techniques to help mitigate water effects on images such as blurriness, low color contrast, and poor quality. This paper presents an evaluation of common underwater image enhancement techniques using a new underwater image dataset. The collected dataset is comprised of 100 images of aquatic plants taken at a shallow depth of up to three meters from three different locations in the Great Lake Superior, USA, via a Remotely Operated Vehicle (ROV) equipped with a high-definition RGB camera. In particular, we use our dataset to benchmark nine state-of-the-art image enhancement models at three different depths using a set of common non-reference image quality evaluation metrics. Then we provide a comparative analysis of the performance of the selected models at different depths and highlight the most prevalent ones. The obtained results show that the selected image enhancement models are capable of producing considerably better-quality images with some models performing better than others at certain depths
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