11 research outputs found

    On-barn pig weight estimation based on body measurements by structure-from-motion (SfM)

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    Information on the body shape of pigs is a key indicator to monitor their performance and health and to control or predict their market weight. Manual measurements are among the most common ways to obtain an indication of animal growth. However, this approach is laborious and difficult, and it may be stressful for both the pigs and the stockman. The present paper proposes the implementation of a Structure from Motion (SfM) photogrammetry approach as a new tool for on-barn animal reconstruction applications. This is possible also to new software tools allowing automatic estimation of camera parameters during the reconstruction process even without a preliminary calibration phase. An analysis on pig body 3D SfM characterization is here proposed, carried out under different conditions in terms of number of camera poses and animal movements. The work takes advantage of the total reconstructed surface as reference index to quantify the quality of the achieved 3D reconstruction, showing how as much as 80% of the total animal area can be characterized

    Evaluation of low-cost depth cameras for agricultural applications

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    Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology- related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at different positions within the image, and cameras usefulness in indoor and outdoor settings. Then, cameras were tested in a swine facility and in a corn field. Five different cameras were used: (1) Microsoft Kinect v.1, (2) Microsoft Kinect v.2, (3) Intel® RealSenseTM Depth Camera D435, (4) ZED Stereo Camera (StereoLabs), and (5) CamBoard Pico Flexx (PMD Technologies). Results indicate that there were significant camera to camera differences for ZED Stereo Camera and Kinect v.1 camera (p \u3c 0.05). All cameras showed an increase in the standard deviation as the distance between camera and object increased; however, the Intel RealSense camera had a larger increase. Time-of-flight cameras had the smallest error between different sizes of objects. Time-of-flight cameras had non-readable zones on the corners of the images. The results indicate that the ToF technology is the best to be used for indoor applications and stereoscopy is the best technology for outdoor applications

    Evaluation of low-cost depth cameras for agricultural applications

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    Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at different positions within the image, and cameras usefulness in indoor and outdoor settings. Then, cameras were tested in a swine facility and in a corn field. Five different cameras were used: (1) Microsoft Kinect v.1, (2) Microsoft Kinect v.2, (3) Intel® RealSense™ Depth Camera D435, (4) ZED Stereo Camera (StereoLabs), and (5) CamBoard Pico Flexx (PMD Technologies). Results indicate that there were significant camera to camera differences for ZED Stereo Camera and Kinect v.1 camera (p \u3c 0.05). All cameras showed an increase in the standard deviation as the distance between camera and object increased; however, the Intel RealSense camera had a larger increase. Time-of-flight cameras had the smallest error between different sizes of objects. Time-of-flight cameras had non-readable zones on the corners of the images. The results indicate that the ToF technolog

    Técnicas de coste reducido para el posicionamiento del paciente en radioterapia percutánea utilizando un sistema de imágenes ópticas

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    Patient positioning is an important part of radiation therapy which is one of the main solutions for the treatment of malignant tissue in the human body. Currently, the most common patient positioning methods expose healthy tissue of the patient's body to extra dangerous radiations. Other non-invasive positioning methods are either not very accurate or are very costly for an average hospital. In this thesis, we explore the possibility of developing a system comprised of affordable hardware and advanced computer vision algorithms that facilitates patient positioning. Our algorithms are based on the usage of affordable RGB-D sensors, image features, ArUco planar markers, and other geometry registration methods. Furthermore, we take advantage of consumer-level computing hardware to make our systems widely accessible. More specifically, we avoid the usage of approaches that need to take advantage of dedicated GPU hardware for general-purpose computing since they are more costly. In different publications, we explore the usage of the mentioned tools to increase the accuracy of reconstruction/localization of the patient in its pose. We also take into account the visualization of the patient's target position with respect to their current position in order to assist the person who performs patient positioning. Furthermore, we make usage of augmented reality in conjunction with a real-time 3D tracking algorithm for better interaction between the program and the operator. We also solve more fundamental problems about ArUco markers that could be used in the future to improve our systems. These include highquality multi-camera calibration and mapping using ArUco markers plus detection of these markers in event cameras which are very useful in the presence of fast camera movement. In the end, we conclude that it is possible to increase the accuracy of 3D reconstruction and localization by combining current computer vision algorithms with fiducial planar markers with RGB-D sensors. This is reflected in the low amount of error we have achieved in our experiments for patient positioning, pushing forward the state of the art for this application.En el tratamiento de tumores malignos en el cuerpo, el posicionamiento del paciente en las sesiones de radioterapia es una cuestión crucial. Actualmente, los métodos más comunes de posicionamiento del paciente exponen tejido sano del mismo a radiaciones peligrosas debido a que no es posible asegurar que la posición del paciente siempre sea la misma que la que tuvo cuando se planificó la zona a radiar. Los métodos que se usan actualmente, o no son precisos o tienen costes que los hacen inasequibles para ser usados en hospitales con financiación limitada. En esta Tesis hemos analizado la posibilidad de desarrollar un sistema compuesto por hardware de bajo coste y métodos avanzados de visión por ordenador que ayuden a que el posicionamiento del paciente sea el mismo en las diferentes sesiones de radioterapia, con respecto a su pose cuando fue se planificó la zona a radiar. La solución propuesta como resultado de la Tesis se basa en el uso de sensores RGB-D, características extraídas de la imagen, marcadores cuadrados denominados ArUco y métodos de registro de la geometría en la imagen. Además, en la solución propuesta, se aprovecha la existencia de hardware convencional de bajo coste para hacer nuestro sistema ampliamente accesible. Más específicamente, evitamos el uso de enfoques que necesitan aprovechar GPU, de mayores costes, para computación de propósito general. Se han obtenido diferentes publicaciones para conseguir el objetivo final. Las mismas describen métodos para aumentar la precisión de la reconstrucción y la localización del paciente en su pose, teniendo en cuenta la visualización de la posición ideal del paciente con respecto a su posición actual, para ayudar al profesional que realiza la colocación del paciente. También se han propuesto métodos de realidad aumentada junto con algoritmos para seguimiento 3D en tiempo real para conseguir una mejor interacción entre el sistema ideado y el profesional que debe realizar esa labor. De forma añadida, también se han propuesto soluciones para problemas fundamentales relacionados con el uso de marcadores cuadrados que han sido utilizados para conseguir el objetivo de la Tesis. Las soluciones propuestas pueden ser empleadas en el futuro para mejorar otros sistemas. Los problemas citados incluyen la calibración y el mapeo multicámara de alta calidad utilizando los marcadores y la detección de estos marcadores en cámaras de eventos, que son muy útiles en presencia de movimientos rápidos de la cámara. Al final, concluimos que es posible aumentar la precisión de la reconstrucción y localización en 3D combinando los actuales algoritmos de visión por ordenador, que usan marcadores cuadrados de referencia, con sensores RGB-D. Los resultados obtenidos con respecto al error que el sistema obtiene al reproducir el posicionamiento del paciente suponen un importante avance en el estado del arte de este tópico

    Advances in Sensors, Big Data and Machine Learning in Intelligent Animal Farming

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    Animal production (e.g., milk, meat, and eggs) provides valuable protein production for human beings and animals. However, animal production is facing several challenges worldwide such as environmental impacts and animal welfare/health concerns. In animal farming operations, accurate and efficient monitoring of animal information and behavior can help analyze the health and welfare status of animals and identify sick or abnormal individuals at an early stage to reduce economic losses and protect animal welfare. In recent years, there has been growing interest in animal welfare. At present, sensors, big data, machine learning, and artificial intelligence are used to improve management efficiency, reduce production costs, and enhance animal welfare. Although these technologies still have challenges and limitations, the application and exploration of these technologies in animal farms will greatly promote the intelligent management of farms. Therefore, this Special Issue will collect original papers with novel contributions based on technologies such as sensors, big data, machine learning, and artificial intelligence to study animal behavior monitoring and recognition, environmental monitoring, health evaluation, etc., to promote intelligent and accurate animal farm management

    Optical Methods in Sensing and Imaging for Medical and Biological Applications

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    The recent advances in optical sources and detectors have opened up new opportunities for sensing and imaging techniques which can be successfully used in biomedical and healthcare applications. This book, entitled ‘Optical Methods in Sensing and Imaging for Medical and Biological Applications’, focuses on various aspects of the research and development related to these areas. The book will be a valuable source of information presenting the recent advances in optical methods and novel techniques, as well as their applications in the fields of biomedicine and healthcare, to anyone interested in this subject

    Real Time Structured Light and Applications

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    On-the-fly dense 3D surface reconstruction for geometry-aware augmented reality.

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    Augmented Reality (AR) is an emerging technology that makes seamless connections between virtual space and the real world by superimposing computer-generated information onto the real-world environment. AR can provide additional information in a more intuitive and natural way than any other information-delivery method that a human has ever in- vented. Camera tracking is the enabling technology for AR and has been well studied for the last few decades. Apart from the tracking problems, sensing and perception of the surrounding environment are also very important and challenging problems. Although there are existing hardware solutions such as Microsoft Kinect and HoloLens that can sense and build the environmental structure, they are either too bulky or too expensive for AR. In this thesis, the challenging real-time dense 3D surface reconstruction technologies are studied and reformulated for the reinvention of basic position-aware AR towards geometry-aware and the outlook of context- aware AR. We initially propose to reconstruct the dense environmental surface using the sparse point from Simultaneous Localisation and Map- ping (SLAM), but this approach is prone to fail in challenging Minimally Invasive Surgery (MIS) scenes such as the presence of deformation and surgical smoke. We subsequently adopt stereo vision with SLAM for more accurate and robust results. With the success of deep learning technology in recent years, we present learning based single image re- construction and achieve the state-of-the-art results. Moreover, we pro- posed context-aware AR, one step further from purely geometry-aware AR towards the high-level conceptual interaction modelling in complex AR environment for enhanced user experience. Finally, a learning-based smoke removal method is proposed to ensure an accurate and robust reconstruction under extreme conditions such as the presence of surgical smoke

    Artificial Intelligence and Ambient Intelligence

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    This book includes a series of scientific papers published in the Special Issue on Artificial Intelligence and Ambient Intelligence at the journal Electronics MDPI. The book starts with an opinion paper on “Relations between Electronics, Artificial Intelligence and Information Society through Information Society Rules”, presenting relations between information society, electronics and artificial intelligence mainly through twenty-four IS laws. After that, the book continues with a series of technical papers that present applications of Artificial Intelligence and Ambient Intelligence in a variety of fields including affective computing, privacy and security in smart environments, and robotics. More specifically, the first part presents usage of Artificial Intelligence (AI) methods in combination with wearable devices (e.g., smartphones and wristbands) for recognizing human psychological states (e.g., emotions and cognitive load). The second part presents usage of AI methods in combination with laser sensors or Wi-Fi signals for improving security in smart buildings by identifying and counting the number of visitors. The last part presents usage of AI methods in robotics for improving robots’ ability for object gripping manipulation and perception. The language of the book is rather technical, thus the intended audience are scientists and researchers who have at least some basic knowledge in computer science
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