Augmented reality (AR) has great potential for blind users because it enables a range of applicat... more Augmented reality (AR) has great potential for blind users because it enables a range of applications that provide audio information about specific locations or directions in the user’s environment. For instance, the CamIO (“Camera Input-Output”) AR app makes physical objects (such as documents, maps, devices and 3D models) accessible to blind and visually impaired persons by providing real-time audio feedback in response to the location on an object that the user is touching (using an inexpensive stylus). An important feature needed by blind users of AR apps such as CamIO is a 3D spatial guidance feature that provides real-time audio feedback to help the user find a desired location on an object. We have devised a simple audio interface to provide verbal guidance towards a target of interest in 3D. The experiment we report with blind participants using this guidance interface demonstrates the feasibility of the approach and its benefit for helping users find locations of interest .
The development of a conceptual site model (CSM) is an invaluable tool used for assessing and pla... more The development of a conceptual site model (CSM) is an invaluable tool used for assessing and planning remedial actions at a contaminated site. The CSM incorporates site-specific, hydrogeologic and geochemical information to identify contaminants of concern, sources of pollution, environmental pathways and retardation mechanisms, and points of exposure. The model is dynamic and continually revised as new information is obtained during the course of investigation. A ground water contamination case study is examined to illustrate the development and application of a CSM. The site is a metal plating facility that has contaminated the ground water with chromium. The CSM was incorporated into a 3-D fate and transport model. The Heavy Metal model, HM-3D, was used to simulate the fate and transport of chromium at the site and evaluate pump-and-treat remediation scenarios.
Computers helping people with special needs : ... International Conference, ICCHP ... : proceedings. International Conference on Computers Helping People with Special Needs
This paper describes recent progress on Crosswatch, a smartphone-based computer vision system dev... more This paper describes recent progress on Crosswatch, a smartphone-based computer vision system developed by the authors for providing guidance to blind and visually impaired pedestrians at traffic intersections. One of Crosswatch's key capabilities is determining the user's location (with precision much better than what is obtainable by GPS) and orientation relative to the crosswalk markings in the intersection that he/she is currently standing at; this capability will be used to help him/her find important features in the intersection, such as walk lights, pushbuttons and crosswalks, and achieve proper alignment to these features. We report on two new contributions to Crosswatch: (a) experiments with a modified user interface, tested by blind volunteer participants, that makes it easier to acquire intersection images than with previous versions of Crosswatch; and (b) a demonstration of the system's ability to localize the user with precision better than what is obtainabl...
Abstract: We are developing computer vision algorithms for sensing important terrain features as ... more Abstract: We are developing computer vision algorithms for sensing important terrain features as an aid to wheelchair navigation, which interpret visual information obtained from images collected by video cameras mounted to the wheelchair. This paper focuses specifically on a novel computer vision algorithm for detecting curbs and other negative obstacles (i.e. anything below the level of the ground, such as holes and drop-offs), which are important and ubiquitous features on and near sidewalks and other walkways. The algorithm we develop extracts as much information as possible from depth information obtained from stereo video cameras (i.e. pairs of cameras mounted close together); other information (e.g. monocular cues such as intensity edges) will be incorporated in the future. We demonstrate experimental results on typical sidewalk scenes.
National Chromium is a metal-plating facility located in Putnam, Connecticut that has been in ope... more National Chromium is a metal-plating facility located in Putnam, Connecticut that has been in operation for 55 years. Chromium has dripped onto the wooden floor and leached into the groundwater. The process that affect the fate and transport of chromium in groundwater are aqueous complexation, adsorption/desorption, precipitation/dissolution, and solute transport. In addition, field data and laboratory studies using soil samples from this site indicate that a predominant retardation process is diffusion into the soil matrix. While aqueous complexation usually takes seconds or less, the time scales of chromium diffusion in soil matrix is years. A three-dimensional multicomponent solute transport model has been developed to study the fate, speciation and transport of chromium. The model has been applied to the National Chromium site in a hind casting to study (1) the interaction among the processes, (2) the implication of chromium diffusion in soil matrix on remediation technologies, ...
We describe a new approach to audio labeling of 3D objects such as appliances, 3D models and maps... more We describe a new approach to audio labeling of 3D objects such as appliances, 3D models and maps that enables a visually impaired person to audio label objects. Our approach to audio labeling is called CamIO, a smartphone app that issues audio labels when the user points to a hotspot (a location of interest on an object) with a handheld stylus viewed by the smartphone camera. The CamIO app allows a user to create a new hotspot location by pointing at the location with a second stylus and recording a personalized audio label for the hotspot. In contrast with other audio labeling approaches that require the object of interest to be constructed of special materials, 3D printed, or equipped with special sensors, CamIO works with virtually any rigid object and requires only a smartphone, a paper barcode pattern mounted to the object of interest, and two inexpensive styluses. Moreover, our approach allows a visually impaired user to create audio labels independently. We describe a co-des...
2014 Canadian Conference on Computer and Robot Vision, 2014
There is growing interest among smartphone users in the ability to determine their precise locati... more There is growing interest among smartphone users in the ability to determine their precise location in their environment for a variety of applications related to wayfinding, travel and shopping. While GPS provides valuable selflocalization estimates, its accuracy is limited to approximately 10 meters in most urban locations. This paper focuses on the self-localization needs of blind or visually impaired travelers, who are faced with the challenge of negotiating street intersections. These travelers need more precise self-localization to help them align themselves properly to crosswalks, signal lights and other features such as walk light pushbuttons. We demonstrate a novel computer vision-based localization approach that is tailored to the street intersection domain. Unlike most work on computer vision-based localization techniques, which typically assume the presence of detailed, highquality 3D models of urban environments, our technique harnesses the availability of simple, ubiquitous satellite imagery (e.g., Google Maps) to create simple maps of each intersection. Not only does this technique scale naturally to the great majority of street intersections in urban areas, but it has the added advantage of incorporating the specific metric information that blind or visually impaired travelers need, namely, the locations of intersection features such as crosswalks. Key to our approach is the integration of IMU (inertial measurement unit) information with geometric information obtained from image panorama stitchings. Finally, we evaluate the localization performance of our algorithm on a dataset of intersection panoramas, demonstrating the feasibility of our approach.
Graphical models provide an attractive framework for modeling a variety of problems in computer v... more Graphical models provide an attractive framework for modeling a variety of problems in computer vision. The advent of powerful inference techniques such as belief propagation (BP) has recently made inference with many of these models tractable. Even so, the enormous size of the state spaces required for some applications can create a heavy computational burden. Pruning is a standard technique for reducing this burden, but since pruning is irreversible it carries the risk of greedily deleting important states, which can subsequently result in gross errors in BP. To address this problem, we propose a novel extension of pruning, which we call dynamic quantization (DQ), that allows BP to adaptively add as well as subtract states as needed. We examine DQ in the context of graphical-model based deformable template matching, in which the state space size is on the order of the number of pixels in an image. The combination of BP and DQ yields deformable templates that are both fast and robu...
We are developing computer vision algorithms for sensing important terrain features as an aid to ... more We are developing computer vision algorithms for sensing important terrain features as an aid to wheelchair navigation, which interpret visual information obtained from images collected by video cameras mounted to the wheelchair. This paper focuses specifically on a novel computer vision algorithm for detecting curbs and other negative obstacles (i.e. anything below the level of the ground, such as holes and drop-offs), which are important and ubiquitous features on and near sidewalks and other walkways. The algorithm we develop extracts as much information as possible from depth information obtained from stereo video cameras (i.e. pairs of cameras mounted close together); other information (e.g. monocular cues such as intensity edges) will be incorporated in the future. We demonstrate experimental results on typical sidewalk scenes.
Modern household appliances, such as microwave ovens and DVD players, increasingly require users ... more Modern household appliances, such as microwave ovens and DVD players, increasingly require users to read an LED or LCD display to operate them, posing a severe obstacle for persons with blindness or visual impairment. While OCR-enabled devices are emerging to address the related problem of reading text in printed documents, they are not designed to tackle the challenge of finding and reading characters in appliance displays. Any system for reading these characters must address the challenge of first locating the characters among substantial amounts of background clutter; moreover, poor contrast and the abundance of specular highlights on the display surface - which degrade the image in an unpredictable way as the camera is moved - motivate the need for a system that processes images at a few frames per second, rather than forcing the user to take several photos, each of which can take seconds to acquire and process, until one is readable.We describe a novel system that acquires video, detects and reads LED/LCD characters in real time, reading them aloud to the user with synthesized speech. The system has been implemented on both a desktop and a cell phone. Experimental results are reported on videos of display images, demonstrating the feasibility of the system.
The distribution of chromium in groundwater are determined by two processes: solute transport and... more The distribution of chromium in groundwater are determined by two processes: solute transport and chemical reactions. The transport of aqueous species is governed by a set of partial differential equations (PDEs), and the speciation of chemical species is governed by a set of nonlinear algebraic equations (AEs). An efficient 1-D multicomponent transport model was developed using the direct substitution approach (DSA). The model incorporates aqueous complexation, surface complexation and precipitation/dissolution. PDEs governing transport processes were discretized and solved together with non-linear AEs for chemical reactions using the Newton-Raphson method. The Jacobian matrix was obtained analytically. The DSA model is about 100% more efficient than a model based on the sequential substitution approach (SIA) commonly used in practice. A 3-D multicomponent transport model was developed based on the 1-D model. The slow process of chromium migration into the soil matrix was modeled b...
Approximately one in ten blind persons uses a wheelchair, and independent travel is currently nex... more Approximately one in ten blind persons uses a wheelchair, and independent travel is currently next to impossible for this population. Conventional blind wayfinding techniques -cane or guide dog -become extremely difficult or impractical in a wheelchair, requiring great physical dexterity and coordination. As a result, independent travel is so difficult that few attempt it, resulting in a widespread lack of awareness of this severely disadvantaged population.
We introduce a new framework for feature grouping based on factor graphs, which are graphical mod... more We introduce a new framework for feature grouping based on factor graphs, which are graphical models that encode interactions among arbitrary numbers of random variables. The ability of factor graphs to express interactions higher than pairwise order (the highest order encountered in most graphical models used in computer vision) is useful for modeling a variety of pattern recognition problems. In particular, we show how this property makes factor graphs a natural framework for performing grouping and segmentation, which we apply to the problem of finding text in natural scenes. We demonstrate an implementation of our factor graph-based algorithm for finding text on a Nokia camera phone, which is intended for eventual use in a camera phone system that finds and reads text (such as street signs) in natural environments for blind users.
Printed text is a ubiquitous form of information that is inaccessible to many blind and visually ... more Printed text is a ubiquitous form of information that is inaccessible to many blind and visually impaired people unless it is represented in a non-visual form such as Braille. OCR (optical character recognition) systems have been used by blind and visually impaired persons for some time to read documents such as books and bills; recently this technology has been packaged in a portable device, such as the smartphone-based kReader Mobile (from K-NFB Reading Technology, Inc.), which allows the user to photograph a document such as a restaurant menu and hear the text read aloud. However, while this kind of OCR system is useful for reading documents at close range (which may still require the user to take a few photographs, waiting a few seconds each time to hear the results, to take one that is correctly centered), it is not intended for signs. (Indeed, the KNFB manual, see knfbreader.com/upgrades_mobile.php , lists "posted signs such as signs on transit vehicles and signs in shop windows" in the "What the Reader Cannot Do" subsection.) Signs provide valuable location-specific information that is useful for wayfinding, but are usually viewed from a distance and are difficult or impossible to find without adequate vision and rapid feedback.
The "Crosswatch" project is a smartphone-based system developed by the authors for providing guid... more The "Crosswatch" project is a smartphone-based system developed by the authors for providing guidance to blind and visually impaired pedestrians at traffic intersections. Building on past work on Crosswatch functionality to help the user achieve proper alignment with the cross-walk and read the status of Walk lights to know when it is time to cross, we outline the direction Crosswatch should take to help realize its potential for becoming a practical system: namely, augmenting com-puter vision with other information sources, including geographic infor-mation systems (GIS) and sensor data, to provide a much larger range of information about traffic intersections to the pedestrian.
2004 Conference on Computer Vision and Pattern Recognition Workshop, 2004
Graphical models provide an attractive framework for shape matching because they are well-suited ... more Graphical models provide an attractive framework for shape matching because they are well-suited to formulating Bayesian models of deformable templates. In addition, the advent of powerful inference techniques such as belief propagation (BP) has recently made these models tractable. However, the enormous size of the state spaces involved in these applications (about the size of the pixel lattice) has restricted their use to models drawing on sparse feature maps (e.g. edges), which are typically unable to cope with missing or occluded features since the locations of missing features are not represented in the state space.
... Visually Impaired Pedestrians at Traffic Intersections Volodymyr Ivanchenko, James Coughlan, ... more ... Visually Impaired Pedestrians at Traffic Intersections Volodymyr Ivanchenko, James Coughlan, and Huiying Shen The Smith-Kettlewell Eye Research Institute, 2318 Fillmore St., San Francisco CA 94115 USA {vivanchenko,coughlan,hshen}@ski.org Abstract. ...
Augmented reality (AR) has great potential for blind users because it enables a range of applicat... more Augmented reality (AR) has great potential for blind users because it enables a range of applications that provide audio information about specific locations or directions in the user’s environment. For instance, the CamIO (“Camera Input-Output”) AR app makes physical objects (such as documents, maps, devices and 3D models) accessible to blind and visually impaired persons by providing real-time audio feedback in response to the location on an object that the user is touching (using an inexpensive stylus). An important feature needed by blind users of AR apps such as CamIO is a 3D spatial guidance feature that provides real-time audio feedback to help the user find a desired location on an object. We have devised a simple audio interface to provide verbal guidance towards a target of interest in 3D. The experiment we report with blind participants using this guidance interface demonstrates the feasibility of the approach and its benefit for helping users find locations of interest .
The development of a conceptual site model (CSM) is an invaluable tool used for assessing and pla... more The development of a conceptual site model (CSM) is an invaluable tool used for assessing and planning remedial actions at a contaminated site. The CSM incorporates site-specific, hydrogeologic and geochemical information to identify contaminants of concern, sources of pollution, environmental pathways and retardation mechanisms, and points of exposure. The model is dynamic and continually revised as new information is obtained during the course of investigation. A ground water contamination case study is examined to illustrate the development and application of a CSM. The site is a metal plating facility that has contaminated the ground water with chromium. The CSM was incorporated into a 3-D fate and transport model. The Heavy Metal model, HM-3D, was used to simulate the fate and transport of chromium at the site and evaluate pump-and-treat remediation scenarios.
Computers helping people with special needs : ... International Conference, ICCHP ... : proceedings. International Conference on Computers Helping People with Special Needs
This paper describes recent progress on Crosswatch, a smartphone-based computer vision system dev... more This paper describes recent progress on Crosswatch, a smartphone-based computer vision system developed by the authors for providing guidance to blind and visually impaired pedestrians at traffic intersections. One of Crosswatch's key capabilities is determining the user's location (with precision much better than what is obtainable by GPS) and orientation relative to the crosswalk markings in the intersection that he/she is currently standing at; this capability will be used to help him/her find important features in the intersection, such as walk lights, pushbuttons and crosswalks, and achieve proper alignment to these features. We report on two new contributions to Crosswatch: (a) experiments with a modified user interface, tested by blind volunteer participants, that makes it easier to acquire intersection images than with previous versions of Crosswatch; and (b) a demonstration of the system's ability to localize the user with precision better than what is obtainabl...
Abstract: We are developing computer vision algorithms for sensing important terrain features as ... more Abstract: We are developing computer vision algorithms for sensing important terrain features as an aid to wheelchair navigation, which interpret visual information obtained from images collected by video cameras mounted to the wheelchair. This paper focuses specifically on a novel computer vision algorithm for detecting curbs and other negative obstacles (i.e. anything below the level of the ground, such as holes and drop-offs), which are important and ubiquitous features on and near sidewalks and other walkways. The algorithm we develop extracts as much information as possible from depth information obtained from stereo video cameras (i.e. pairs of cameras mounted close together); other information (e.g. monocular cues such as intensity edges) will be incorporated in the future. We demonstrate experimental results on typical sidewalk scenes.
National Chromium is a metal-plating facility located in Putnam, Connecticut that has been in ope... more National Chromium is a metal-plating facility located in Putnam, Connecticut that has been in operation for 55 years. Chromium has dripped onto the wooden floor and leached into the groundwater. The process that affect the fate and transport of chromium in groundwater are aqueous complexation, adsorption/desorption, precipitation/dissolution, and solute transport. In addition, field data and laboratory studies using soil samples from this site indicate that a predominant retardation process is diffusion into the soil matrix. While aqueous complexation usually takes seconds or less, the time scales of chromium diffusion in soil matrix is years. A three-dimensional multicomponent solute transport model has been developed to study the fate, speciation and transport of chromium. The model has been applied to the National Chromium site in a hind casting to study (1) the interaction among the processes, (2) the implication of chromium diffusion in soil matrix on remediation technologies, ...
We describe a new approach to audio labeling of 3D objects such as appliances, 3D models and maps... more We describe a new approach to audio labeling of 3D objects such as appliances, 3D models and maps that enables a visually impaired person to audio label objects. Our approach to audio labeling is called CamIO, a smartphone app that issues audio labels when the user points to a hotspot (a location of interest on an object) with a handheld stylus viewed by the smartphone camera. The CamIO app allows a user to create a new hotspot location by pointing at the location with a second stylus and recording a personalized audio label for the hotspot. In contrast with other audio labeling approaches that require the object of interest to be constructed of special materials, 3D printed, or equipped with special sensors, CamIO works with virtually any rigid object and requires only a smartphone, a paper barcode pattern mounted to the object of interest, and two inexpensive styluses. Moreover, our approach allows a visually impaired user to create audio labels independently. We describe a co-des...
2014 Canadian Conference on Computer and Robot Vision, 2014
There is growing interest among smartphone users in the ability to determine their precise locati... more There is growing interest among smartphone users in the ability to determine their precise location in their environment for a variety of applications related to wayfinding, travel and shopping. While GPS provides valuable selflocalization estimates, its accuracy is limited to approximately 10 meters in most urban locations. This paper focuses on the self-localization needs of blind or visually impaired travelers, who are faced with the challenge of negotiating street intersections. These travelers need more precise self-localization to help them align themselves properly to crosswalks, signal lights and other features such as walk light pushbuttons. We demonstrate a novel computer vision-based localization approach that is tailored to the street intersection domain. Unlike most work on computer vision-based localization techniques, which typically assume the presence of detailed, highquality 3D models of urban environments, our technique harnesses the availability of simple, ubiquitous satellite imagery (e.g., Google Maps) to create simple maps of each intersection. Not only does this technique scale naturally to the great majority of street intersections in urban areas, but it has the added advantage of incorporating the specific metric information that blind or visually impaired travelers need, namely, the locations of intersection features such as crosswalks. Key to our approach is the integration of IMU (inertial measurement unit) information with geometric information obtained from image panorama stitchings. Finally, we evaluate the localization performance of our algorithm on a dataset of intersection panoramas, demonstrating the feasibility of our approach.
Graphical models provide an attractive framework for modeling a variety of problems in computer v... more Graphical models provide an attractive framework for modeling a variety of problems in computer vision. The advent of powerful inference techniques such as belief propagation (BP) has recently made inference with many of these models tractable. Even so, the enormous size of the state spaces required for some applications can create a heavy computational burden. Pruning is a standard technique for reducing this burden, but since pruning is irreversible it carries the risk of greedily deleting important states, which can subsequently result in gross errors in BP. To address this problem, we propose a novel extension of pruning, which we call dynamic quantization (DQ), that allows BP to adaptively add as well as subtract states as needed. We examine DQ in the context of graphical-model based deformable template matching, in which the state space size is on the order of the number of pixels in an image. The combination of BP and DQ yields deformable templates that are both fast and robu...
We are developing computer vision algorithms for sensing important terrain features as an aid to ... more We are developing computer vision algorithms for sensing important terrain features as an aid to wheelchair navigation, which interpret visual information obtained from images collected by video cameras mounted to the wheelchair. This paper focuses specifically on a novel computer vision algorithm for detecting curbs and other negative obstacles (i.e. anything below the level of the ground, such as holes and drop-offs), which are important and ubiquitous features on and near sidewalks and other walkways. The algorithm we develop extracts as much information as possible from depth information obtained from stereo video cameras (i.e. pairs of cameras mounted close together); other information (e.g. monocular cues such as intensity edges) will be incorporated in the future. We demonstrate experimental results on typical sidewalk scenes.
Modern household appliances, such as microwave ovens and DVD players, increasingly require users ... more Modern household appliances, such as microwave ovens and DVD players, increasingly require users to read an LED or LCD display to operate them, posing a severe obstacle for persons with blindness or visual impairment. While OCR-enabled devices are emerging to address the related problem of reading text in printed documents, they are not designed to tackle the challenge of finding and reading characters in appliance displays. Any system for reading these characters must address the challenge of first locating the characters among substantial amounts of background clutter; moreover, poor contrast and the abundance of specular highlights on the display surface - which degrade the image in an unpredictable way as the camera is moved - motivate the need for a system that processes images at a few frames per second, rather than forcing the user to take several photos, each of which can take seconds to acquire and process, until one is readable.We describe a novel system that acquires video, detects and reads LED/LCD characters in real time, reading them aloud to the user with synthesized speech. The system has been implemented on both a desktop and a cell phone. Experimental results are reported on videos of display images, demonstrating the feasibility of the system.
The distribution of chromium in groundwater are determined by two processes: solute transport and... more The distribution of chromium in groundwater are determined by two processes: solute transport and chemical reactions. The transport of aqueous species is governed by a set of partial differential equations (PDEs), and the speciation of chemical species is governed by a set of nonlinear algebraic equations (AEs). An efficient 1-D multicomponent transport model was developed using the direct substitution approach (DSA). The model incorporates aqueous complexation, surface complexation and precipitation/dissolution. PDEs governing transport processes were discretized and solved together with non-linear AEs for chemical reactions using the Newton-Raphson method. The Jacobian matrix was obtained analytically. The DSA model is about 100% more efficient than a model based on the sequential substitution approach (SIA) commonly used in practice. A 3-D multicomponent transport model was developed based on the 1-D model. The slow process of chromium migration into the soil matrix was modeled b...
Approximately one in ten blind persons uses a wheelchair, and independent travel is currently nex... more Approximately one in ten blind persons uses a wheelchair, and independent travel is currently next to impossible for this population. Conventional blind wayfinding techniques -cane or guide dog -become extremely difficult or impractical in a wheelchair, requiring great physical dexterity and coordination. As a result, independent travel is so difficult that few attempt it, resulting in a widespread lack of awareness of this severely disadvantaged population.
We introduce a new framework for feature grouping based on factor graphs, which are graphical mod... more We introduce a new framework for feature grouping based on factor graphs, which are graphical models that encode interactions among arbitrary numbers of random variables. The ability of factor graphs to express interactions higher than pairwise order (the highest order encountered in most graphical models used in computer vision) is useful for modeling a variety of pattern recognition problems. In particular, we show how this property makes factor graphs a natural framework for performing grouping and segmentation, which we apply to the problem of finding text in natural scenes. We demonstrate an implementation of our factor graph-based algorithm for finding text on a Nokia camera phone, which is intended for eventual use in a camera phone system that finds and reads text (such as street signs) in natural environments for blind users.
Printed text is a ubiquitous form of information that is inaccessible to many blind and visually ... more Printed text is a ubiquitous form of information that is inaccessible to many blind and visually impaired people unless it is represented in a non-visual form such as Braille. OCR (optical character recognition) systems have been used by blind and visually impaired persons for some time to read documents such as books and bills; recently this technology has been packaged in a portable device, such as the smartphone-based kReader Mobile (from K-NFB Reading Technology, Inc.), which allows the user to photograph a document such as a restaurant menu and hear the text read aloud. However, while this kind of OCR system is useful for reading documents at close range (which may still require the user to take a few photographs, waiting a few seconds each time to hear the results, to take one that is correctly centered), it is not intended for signs. (Indeed, the KNFB manual, see knfbreader.com/upgrades_mobile.php , lists "posted signs such as signs on transit vehicles and signs in shop windows" in the "What the Reader Cannot Do" subsection.) Signs provide valuable location-specific information that is useful for wayfinding, but are usually viewed from a distance and are difficult or impossible to find without adequate vision and rapid feedback.
The "Crosswatch" project is a smartphone-based system developed by the authors for providing guid... more The "Crosswatch" project is a smartphone-based system developed by the authors for providing guidance to blind and visually impaired pedestrians at traffic intersections. Building on past work on Crosswatch functionality to help the user achieve proper alignment with the cross-walk and read the status of Walk lights to know when it is time to cross, we outline the direction Crosswatch should take to help realize its potential for becoming a practical system: namely, augmenting com-puter vision with other information sources, including geographic infor-mation systems (GIS) and sensor data, to provide a much larger range of information about traffic intersections to the pedestrian.
2004 Conference on Computer Vision and Pattern Recognition Workshop, 2004
Graphical models provide an attractive framework for shape matching because they are well-suited ... more Graphical models provide an attractive framework for shape matching because they are well-suited to formulating Bayesian models of deformable templates. In addition, the advent of powerful inference techniques such as belief propagation (BP) has recently made these models tractable. However, the enormous size of the state spaces involved in these applications (about the size of the pixel lattice) has restricted their use to models drawing on sparse feature maps (e.g. edges), which are typically unable to cope with missing or occluded features since the locations of missing features are not represented in the state space.
... Visually Impaired Pedestrians at Traffic Intersections Volodymyr Ivanchenko, James Coughlan, ... more ... Visually Impaired Pedestrians at Traffic Intersections Volodymyr Ivanchenko, James Coughlan, and Huiying Shen The Smith-Kettlewell Eye Research Institute, 2318 Fillmore St., San Francisco CA 94115 USA {vivanchenko,coughlan,hshen}@ski.org Abstract. ...
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