1,616 research outputs found

    Bilevel Fast Scene Adaptation for Low-Light Image Enhancement

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    Enhancing images in low-light scenes is a challenging but widely concerned task in the computer vision. The mainstream learning-based methods mainly acquire the enhanced model by learning the data distribution from the specific scenes, causing poor adaptability (even failure) when meeting real-world scenarios that have never been encountered before. The main obstacle lies in the modeling conundrum from distribution discrepancy across different scenes. To remedy this, we first explore relationships between diverse low-light scenes based on statistical analysis, i.e., the network parameters of the encoder trained in different data distributions are close. We introduce the bilevel paradigm to model the above latent correspondence from the perspective of hyperparameter optimization. A bilevel learning framework is constructed to endow the scene-irrelevant generality of the encoder towards diverse scenes (i.e., freezing the encoder in the adaptation and testing phases). Further, we define a reinforced bilevel learning framework to provide a meta-initialization for scene-specific decoder to further ameliorate visual quality. Moreover, to improve the practicability, we establish a Retinex-induced architecture with adaptive denoising and apply our built learning framework to acquire its parameters by using two training losses including supervised and unsupervised forms. Extensive experimental evaluations on multiple datasets verify our adaptability and competitive performance against existing state-of-the-art works. The code and datasets will be available at https://github.com/vis-opt-group/BL

    Real-Time Statistics for Padel Tennis Using Artificial Intelligence

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    O Padel, desporto conhecido pelo seu crescimento explosivo e jogabilidade emocionante, está à beira de uma revolução tecnológica. Com o objetivo de transformar o jogo de Padel através do uso criativo de técnicas de deteção de objetos e Deep Learning, esta dissertação de mestrado investiga a junção da Inteligência Arti cial (IA) e do Padel. O principal objetivo é usar a IA para produzir estatísticas em tempo real que darão aos jogadores, treinadores e fãs um melhor conhecimento das complexidades do Padel e dos meios para levar o jogo a novos patamares. Esta dissertação explora a monitorização e localização em tempo real dos jogadores e da bola dentro do campo, através de algoritmos de visão computacional. As Redes Neu ronais de Convolução (RNC), um tipo de modelo de Deep Learning, são essenciais para o reconhecimento preciso de eventos e ações importantes durante o jogo. A criação de um sistema baseado em IA que produz dados instantâneos para partidas de Padel é a inovação central desta dissertação. Estas estatísticas oferecem uma visão analítica e detalhada de cada jogo, tendo em consideração os movimentos dos jogadores, as trajetórias da bola e a dinâmica do jogo. Esta dissertação não promove apenas o Padel, mas também cria novas oportunidades para a utilização de IA em outros desportos.The sport of Padel, known for its explosive growth and exciting gameplay, is on the verge of a technological revolution. With the goal of transforming the game of Padel through the creative use of object detection and deep learning techniques, this master's thesis investi gates the junction of Arti cial Intelligence (AI) and Padel. The main goal is to use AI to produce real-time statistics that will give players, coaches and fans a better knowledge of the complexities of Padel and the means to take the game to new heights. This dissertation explores the real-time tracking and localization of players and the ball within the court by utilizing cutting-edge computer vision algorithms. Convolution Neural Networks (CNN), one type of deep learning model, are essential for the precise recognition of important gaming events and actions. The creation of an AI-driven system that produces in-the-moment data for Padel matches is the central innovation of this dissertation. These statistics o er a detailed and analytical view of each game by taking into account player movements, ball trajectories, and game dynamics. This dissertation not only advances the sport of Padel but also creates new op portunities for the use of AI in other sports analytics

    Task-adaptable, Pervasive Perception for Robots Performing Everyday Manipulation

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    Intelligent robotic agents that help us in our day-to-day chores have been an aspiration of robotics researchers for decades. More than fifty years since the creation of the first intelligent mobile robotic agent, robots are still struggling to perform seemingly simple tasks, such as setting or cleaning a table. One of the reasons for this is that the unstructured environments these robots are expected to work in impose demanding requirements on a robota s perception system. Depending on the manipulation task the robot is required to execute, different parts of the environment need to be examined, the objects in it found and functional parts of these identified. This is a challenging task, since the visual appearance of the objects and the variety of scenes they are found in are large. This thesis proposes to treat robotic visual perception for everyday manipulation tasks as an open question-asnswering problem. To this end RoboSherlock, a framework for creating task-adaptable, pervasive perception systems is presented. Using the framework, robot perception is addressed from a systema s perspective and contributions to the state-of-the-art are proposed that introduce several enhancements which scale robot perception toward the needs of human-level manipulation. The contributions of the thesis center around task-adaptability and pervasiveness of perception systems. A perception task-language and a language interpreter that generates task-relevant perception plans is proposed. The task-language and task-interpreter leverage the power of knowledge representation and knowledge-based reasoning in order to enhance the question-answering capabilities of the system. Pervasiveness, a seamless integration of past, present and future percepts, is achieved through three main contributions: a novel way for recording, replaying and inspecting perceptual episodic memories, a new perception component that enables pervasive operation and maintains an object belief state and a novel prospection component that enables robots to relive their past experiences and anticipate possible future scenarios. The contributions are validated through several real world robotic experiments that demonstrate how the proposed system enhances robot perception

    A lightweight network for improving wheat ears detection and counting based on YOLOv5s

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    IntroductionRecognizing wheat ears plays a crucial role in predicting wheat yield. Employing deep learning methods for wheat ears identification is the mainstream method in current research and applications. However, such methods still face challenges, such as high computational parameter volume, large model weights, and slow processing speeds, making it difficult to apply them for real-time identification tasks on limited hardware resources in the wheat field. Therefore, exploring lightweight wheat ears detection methods for real-time recognition holds significant importance.MethodsThis study proposes a lightweight method for detecting and counting wheat ears based on YOLOv5s. It utilizes the ShuffleNetV2 lightweight convolutional neural network to optimize the YOLOv5s model by reducing the number of parameters and simplifying the complexity of the calculation processes. In addition, a lightweight upsampling operator content-aware reassembly of features is introduced in the feature pyramid structure to eliminate the impact of the lightweight process on the model detection performance. This approach aims to improve the spatial resolution of the feature images, enhance the effectiveness of the perceptual field, and reduce information loss. Finally, by introducing the dynamic target detection head, the shape of the detection head and the feature extraction strategy can be dynamically adjusted, and the detection accuracy can be improved when encountering wheat ears with large-scale changes, diverse shapes, or significant orientation variations.Results and discussionThis study uses the global wheat head detection dataset and incorporates the local experimental dataset to improve the robustness and generalization of the proposed model. The weight, FLOPs and mAP of this model are 2.9 MB, 2.5 * 109 and 94.8%, respectively. The linear fitting determination coefficients R2 for the model test result and actual value of global wheat head detection dataset and local experimental Site are 0.94 and 0.97, respectively. The improved lightweight model can better meet the requirements of precision wheat ears counting and play an important role in embedded systems, mobile devices, or other hardware systems with limited computing resources

    Enhancing Road Infrastructure Monitoring: Integrating Drones for Weather-Aware Pothole Detection

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    The abstract outlines the research proposal focused on the utilization of Unmanned Aerial Vehicles (UAVs) for monitoring potholes in road infrastructure affected by various weather conditions. The study aims to investigate how different materials used to fill potholes, such as water, grass, sand, and snow-ice, are impacted by seasonal weather changes, ultimately affecting the performance of pavement structures. By integrating weather-aware monitoring techniques, the research seeks to enhance the rigidity and resilience of road surfaces, thereby contributing to more effective pavement management systems. The proposed methodology involves UAV image-based monitoring combined with advanced super-resolution algorithms to improve image refinement, particularly at high flight altitudes. Through case studies and experimental analysis, the study aims to assess the geometric precision of 3D models generated from aerial images, with a specific focus on road pavement distress monitoring. Overall, the research aims to address the challenges of traditional road failure detection methods by exploring cost-effective 3D detection techniques using UAV technology, thereby ensuring safer roadways for all users

    High-performance hardware accelerators for image processing in space applications

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    Mars is a hard place to reach. While there have been many notable success stories in getting probes to the Red Planet, the historical record is full of bad news. The success rate for actually landing on the Martian surface is even worse, roughly 30%. This low success rate must be mainly credited to the Mars environment characteristics. In the Mars atmosphere strong winds frequently breath. This phenomena usually modifies the lander descending trajectory diverging it from the target one. Moreover, the Mars surface is not the best place where performing a safe land. It is pitched by many and close craters and huge stones, and characterized by huge mountains and hills (e.g., Olympus Mons is 648 km in diameter and 27 km tall). For these reasons a mission failure due to a landing in huge craters, on big stones or on part of the surface characterized by a high slope is highly probable. In the last years, all space agencies have increased their research efforts in order to enhance the success rate of Mars missions. In particular, the two hottest research topics are: the active debris removal and the guided landing on Mars. The former aims at finding new methods to remove space debris exploiting unmanned spacecrafts. These must be able to autonomously: detect a debris, analyses it, in order to extract its characteristics in terms of weight, speed and dimension, and, eventually, rendezvous with it. In order to perform these tasks, the spacecraft must have high vision capabilities. In other words, it must be able to take pictures and process them with very complex image processing algorithms in order to detect, track and analyse the debris. The latter aims at increasing the landing point precision (i.e., landing ellipse) on Mars. Future space-missions will increasingly adopt Video Based Navigation systems to assist the entry, descent and landing (EDL) phase of space modules (e.g., spacecrafts), enhancing the precision of automatic EDL navigation systems. For instance, recent space exploration missions, e.g., Spirity, Oppurtunity, and Curiosity, made use of an EDL procedure aiming at following a fixed and precomputed descending trajectory to reach a precise landing point. This approach guarantees a maximum landing point precision of 20 km. By comparing this data with the Mars environment characteristics, it is possible to understand how the mission failure probability still remains really high. A very challenging problem is to design an autonomous-guided EDL system able to even more reduce the landing ellipse, guaranteeing to avoid the landing in dangerous area of Mars surface (e.g., huge craters or big stones) that could lead to the mission failure. The autonomous behaviour of the system is mandatory since a manual driven approach is not feasible due to the distance between Earth and Mars. Since this distance varies from 56 to 100 million of km approximately due to the orbit eccentricity, even if a signal transmission at the light speed could be possible, in the best case the transmission time would be around 31 minutes, exceeding so the overall duration of the EDL phase. In both applications, algorithms must guarantee self-adaptability to the environmental conditions. Since the Mars (and in general the space) harsh conditions are difficult to be predicted at design time, these algorithms must be able to automatically tune the internal parameters depending on the current conditions. Moreover, real-time performances are another key factor. Since a software implementation of these computational intensive tasks cannot reach the required performances, these algorithms must be accelerated via hardware. For this reasons, this thesis presents my research work done on advanced image processing algorithms for space applications and the associated hardware accelerators. My research activity has been focused on both the algorithm and their hardware implementations. Concerning the first aspect, I mainly focused my research effort to integrate self-adaptability features in the existing algorithms. While concerning the second, I studied and validated a methodology to efficiently develop, verify and validate hardware components aimed at accelerating video-based applications. This approach allowed me to develop and test high performance hardware accelerators that strongly overcome the performances of the actual state-of-the-art implementations. The thesis is organized in four main chapters. Chapter 2 starts with a brief introduction about the story of digital image processing. The main content of this chapter is the description of space missions in which digital image processing has a key role. A major effort has been spent on the missions in which my research activity has a substantial impact. In particular, for these missions, this chapter deeply analizes and evaluates the state-of-the-art approaches and algorithms. Chapter 3 analyzes and compares the two technologies used to implement high performances hardware accelerators, i.e., Application Specific Integrated Circuits (ASICs) and Field Programmable Gate Arrays (FPGAs). Thanks to this information the reader may understand the main reasons behind the decision of space agencies to exploit FPGAs instead of ASICs for high-performance hardware accelerators in space missions, even if FPGAs are more sensible to Single Event Upsets (i.e., transient error induced on hardware component by alpha particles and solar radiation in space). Moreover, this chapter deeply describes the three available space-grade FPGA technologies (i.e., One-time Programmable, Flash-based, and SRAM-based), and the main fault-mitigation techniques against SEUs that are mandatory for employing space-grade FPGAs in actual missions. Chapter 4 describes one of the main contribution of my research work: a library of high-performance hardware accelerators for image processing in space applications. The basic idea behind this library is to offer to designers a set of validated hardware components able to strongly speed up the basic image processing operations commonly used in an image processing chain. In other words, these components can be directly used as elementary building blocks to easily create a complex image processing system, without wasting time in the debug and validation phase. This library groups the proposed hardware accelerators in IP-core families. The components contained in a same family share the same provided functionality and input/output interface. This harmonization in the I/O interface enables to substitute, inside a complex image processing system, components of the same family without requiring modifications to the system communication infrastructure. In addition to the analysis of the internal architecture of the proposed components, another important aspect of this chapter is the methodology used to develop, verify and validate the proposed high performance image processing hardware accelerators. This methodology involves the usage of different programming and hardware description languages in order to support the designer from the algorithm modelling up to the hardware implementation and validation. Chapter 5 presents the proposed complex image processing systems. In particular, it exploits a set of actual case studies, associated with the most recent space agency needs, to show how the hardware accelerator components can be assembled to build a complex image processing system. In addition to the hardware accelerators contained in the library, the described complex system embeds innovative ad-hoc hardware components and software routines able to provide high performance and self-adaptable image processing functionalities. To prove the benefits of the proposed methodology, each case study is concluded with a comparison with the current state-of-the-art implementations, highlighting the benefits in terms of performances and self-adaptability to the environmental conditions

    Bridging Domain Gaps for Cross-Spectrum and Long-Range Face Recognition Using Domain Adaptive Machine Learning

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    Face recognition technology has witnessed significant advancements in recent decades, enabling its widespread adoption in various applications such as security, surveillance, and biometrics applications. However, one of the primary challenges faced by existing face recognition systems is their limited performance when presented with images from different modalities or domains( such as infrared to visible, long range to close range, nighttime to daytime, profile to f rontal, e tc.) Additionally, advancements in camera sensors, analytics beyond the visible spectrum, and the increasing size of cross-modal datasets have led to a particular interest in cross-modal learning for face recognition in the biometrics and computer vision community. Despite a relatively large gap between source and target domains, existing approaches reduce or bridge such domain gaps by either synthesizing face imagery in the target domain using face imagery from the source domain, or by learning cross-modal image representations that are robust to both the source and the target domain. Therefore, this dissertation presents the design and implementation of a novel domain adaptation framework leveraging robust image representations to achieve state-of-the art performance in cross-spectrum and long-range face recognition. The proposed methods use machine learning and deep learning techniques to (1) efficiently ex tract an d le arn do main-invariant embedding from face imagery, (2) learn a mapping from the source to the target domain, and (3) evaluate the proposed framework on several cross-modal face datasets

    Video Face Swapping

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    Face swapping is the challenge of replacing one or multiple faces in a target image with a face from a source image, the source image conditions need to be transformed in order to match the conditions in the target image (lighting and pose). A code for Image Face Swapping (IFS) was refactored and used to perform face swapping in videos. The basic logic behind Video Face Swapping (VFS) is the same as the one used for IFS since a video is just a sequence of images (frames) stitched together to imitate movement. In order to achieve VFS, the face(s) in an input image are detected, their facial landmarks key points are calculated and assigned to their corresponding (X,Y) coordinates, subsequently the faces are aligned using a procrustes analysis, next a mask is created for each image in order to determine what parts of the source and target image need to be shown in the output, then the source image shape has to warp onto the shape of the target image and for the output to look as natural as possible, color correction is performed. Finally, the two masks are blended to generate a new image output showing the face swap. The results were analysed and obstacles of the VFS code were identified and optimization of the code was conducted. In estonian: Näovahetusena mõistetakse käesolevalt lähtekujutiselt saadud ühe või mitme näo asendamist sihtpildil. Lähtekujutise tingimusi peab transformeerima, et nad ühtiksid sihtpildiga (valgus, asend). Pildi näovahetus (IFS, Image Face Swapping) koodi refaktoreeriti ja kasutati video näovahetuseks. Video näovahetuse (Video Face Swapping, VFS) põhiline loogika on sama kui IFSi puhul, kuna video on olemuselt ühendatud kujutiste järjestus, mis imiteerib liikumist. VFSi saavutamiseks tuvastatakse nägu (näod) sisendkujutisel, arvutatakse näotuvastusalgoritmi abil näojoonte koordinaadid, pärast mida joondatakse näod Procrustese meetodiga. Järgnevalt luuakse igale kujutisele image-mask, määratlemaks, milliseid lähte- ja sihtkujutise osi on vaja näidata väljundina; seejärel ühitatakse lähte- ja sihtkujutise kujud ja võimalikult loomuliku tulemuse jaoks viiakse läbi värvikorrektsioon. Lõpuks hajutatakse kaks maski uueks väljundkujutiseks, millel on näha näovahetuse tulemus. Tulemusi analüüsiti ja tuvastati VFS koodi takistused ning seejärel optimeeriti koodi
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