this paper presents an integrated region-based and gradient-based supervised method for segmentation of a patient magnetic resonance images (MRI) of the shoulder joint. the method is noninvasive, anatomy-based and req...
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To perform as desired in a dynamic environment a vision system must adapt to a variety of operating conditions by selecting vision modules, tuning their parameters, and controlling image acquisition. Knowleage-based (...
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ISBN:
(纸本)9780769527864
To perform as desired in a dynamic environment a vision system must adapt to a variety of operating conditions by selecting vision modules, tuning their parameters, and controlling image acquisition. Knowleage-based (KB) controller-agents that reason over explicitly represented knowledge and interact withtheir environment can be used for this task;however the lack of a unifying methodology and development tools makes KB controllers difficult to create, maintain, and reuse. this paper presents the INVICON toolkit, based on the IndiGolog agent programming language with elements from control theory. It provides a basic methodology, a vision module declaration template, a suite of control components, and support tools for KB controller development. We have evaluated INVICON in two case studies that involved controlling vision-based pose estimation systems. the case studies show that INVICON reduces the effort needed to build. KB controllers for challenging domains and improves their flexibility and robustness.
this paper introduces a number of innovative no-reference algorithms to assess the perceived quality of real-time analog and digital television and video streams. A prototype system is developed to locate and measure ...
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ISBN:
(纸本)9780769527864
this paper introduces a number of innovative no-reference algorithms to assess the perceived quality of real-time analog and digital television and video streams. A prototype system is developed to locate and measure the impact of three types of impairments that commonly impair television and video signals. Analog sequences are tested for the presence of random noise. In the case of digital signals, two fundamental types of errors are of interest. the first is the blocking artifact that is so pervasive among DCT-based compression schemes such as MPEG. the second category includes errors caused by random changes to the bit stream of a signal. Of the various forms that these distortions may take on, only those that appear as "colored blocks " are detected by this system. Ideas to address the remaining issues are discussed.
An increasingly popular approach to support military forces deployed in urban environments consists in using autonomous robots to carry on critical tasks such as mapping and surveillance. In order to cope withthe com...
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ISBN:
(纸本)9780769527864
An increasingly popular approach to support military forces deployed in urban environments consists in using autonomous robots to carry on critical tasks such as mapping and surveillance. In order to cope withthe complex obstacles and structures found it? this operational context, robots should be able to perceive and analyze their world in 3D. the method presented in this paper uses a 3D volumetric sensor to efficiency map and explore urban environments with an autonomous robotic platform. A key feature of our work is that the 3D model of the environment is preserved all along the process using a multiresolution octree. this way, every module can access the information it contains to achieve its tasks. Simulation and real word tests were performed to validate the performance of the integrated system and are presented at the end of the paper.
Catadioptric vision systems have been studied in the realm of visual servoing of mobile and articulated robots for the past decade. they are considered superior to a single camera system because of their larger field ...
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ISBN:
(纸本)9781424410200
Catadioptric vision systems have been studied in the realm of visual servoing of mobile and articulated robots for the past decade. they are considered superior to a single camera system because of their larger field of view and higher resolution. this paper presents a new calibration method to estimate the tilt of a mobile robot equipped with a central Catadioptric vision system moving on rough terrains. the proposed approach is based on the spatial projection of a set of parallel lines onto the image plane of an orthographic camera linked with a parabolic mirror. A methodology was developed to estimate 3-axis orientation of the Catadioptirc camera mounted on a mobile robotthrough information obtained from the 2D image. Furthermore, a visual servoing strategy was developed to drive a mobile robot from a given configuration to a target configuration while accounting for tilt disturbances imposed by the terrain. the performance of the proposed method is evaluated via computer simulations.
the use of localized principal component analysis is examined for visual position determination in the presence of varying degrees of occlusions. Occlusions lead to substantial position measurement errors when project...
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ISBN:
(纸本)9780769527864
the use of localized principal component analysis is examined for visual position determination in the presence of varying degrees of occlusions. Occlusions lead to substantial position measurement errors when projecting images into eigenspace. One way to improve robustness to occlusions is to select small sub-windows so that if some sub-windows are occluded, others can still accurately identify, position. the location of candidate sub-windows are predetermined from a set of training images by subtracting the average image from each and then selecting regions using an attention operator Since attention operators can be computationally time-intensive, the location of all sub-windows are determined a-priori during the training phase. the sub-windows in each of the training images are then projected into eigenspace. Once the training phase is complete, the run-time execution can be performed efficiently since all the sub-windows have been preselected. Input images are classified by each sub-window;majority voting is then used to determine the position estimate. Various experiments are performed including linear and rotational motion, and the ego motion of a mobile robot. this technique is shown to provide greater position measurement accuracy in the presence of severe occlusions as compared to the projection of entire images.
Polycystic ovary syndrome (PCOS) is an endocrine abnormality with multiple diagnostic criteria due to its heterogenic manifestations. One of the diagnostic criteria includes analysis of ultrasound images of ovaries fo...
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ISBN:
(纸本)9780769527864
Polycystic ovary syndrome (PCOS) is an endocrine abnormality with multiple diagnostic criteria due to its heterogenic manifestations. One of the diagnostic criteria includes analysis of ultrasound images of ovaries for the detection Of number size, and distribution of follicles within the ovary. this involves manual tracing and counting of follicles on the ultrasound images to determine the presence of a polycystic ovary (PCO). We describe a novel method that automates PCO detection. Our algorithm involves segmentation of follicles from ultrasound images, quantifying the attributes of the automatically segmented follicles using stereology, storing follicle attributes as feature vectors, and finally classification of the feature vector into two categories. the classification categories are: PCO present and PCO absent. An automatic PCO diagnostic tool would save considerable time spent on manual tracing of follicles and measuring the length and width of every follicle. Our procedure was able to achieve classification accuracy of 92.86% using a linear discriminant classifier Our classifier will improve the rapidity and accuracy of PCOS diagnosis, reducing the risk of the severe complications that can arise from delayed diagnosis.
the proceedings contain 63 papers. the topics discussed include: extrinsic recalibration in camera networks;screen camera calibration using a spherical mirror;a simple operator for very precise estimation of ellipses;...
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ISBN:
(纸本)0769527868
the proceedings contain 63 papers. the topics discussed include: extrinsic recalibration in camera networks;screen camera calibration using a spherical mirror;a simple operator for very precise estimation of ellipses;training database adequacy analysis for learning-based super-resolution;extracting salient objects from operator-framed images;learning saccadic gaze control via motion prediction;efficient camera motion and 3D recovery using an inertial sensor;can Lucas-Kanade be used to estimate motion parallax in 3D cluttered scenes;local graph matching for object category recognition;efficient registration of 3D SPHARM surfaces;computing view-normalized body parts trajectories;automated detection of mitosis in embryonic tissues;computer assisted detection of polycystic ovary morphology in ultrasound images;automatic detection and clustering of actor faces based on spectral clustering techniques;and petri net-based cooperation in multi-agent systems.
this paper reports on the implementation of a GPU-based, real-time eye blink detector on very low contrast images acquired under near-infrared illumination. this detector is part of a multi-sensor data acquisition and...
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In this paper, a novel visual servoing technique for a 5-DOF mobile manipulator with an eye-to-hand camera configuration is introduced the proposed technique can be categorized as an image based (or 2D) visual servoin...
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ISBN:
(纸本)9781424410200
In this paper, a novel visual servoing technique for a 5-DOF mobile manipulator with an eye-to-hand camera configuration is introduced the proposed technique can be categorized as an image based (or 2D) visual servoing using a fixed camera in conjunction with a conic mirror (aka, an omni-directional camera system) providing panoramic vision. Two fictitious landmarks mounted on robot's end-effector along withtheir mirror reflections, when viewed by the camera, provide enough information for 3D reasoning based on the four points viewed on the image plane. Instead of directly using the image features associated withthese four points, five new image features are chosen to make the image Jacobian of full rank A dual estimation/control strategy based on Extended Kalman Filter (EKF) is utilized to (1) estimate camera's intrinsic and extrinsic parameters, and (2) track the coordinates of the landmarks and their reflections on the image plane. the relationship between the translational and rotational velocity of a frame attached to the robot's end-effector and rate of change of the proposed image features are fully formulated the robustness of the proposed visual servoing technique is illustrated through computer simulations.
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