Publications

Journals
Richard Monette, Anthony Whitehead. "Particle-Based Participating Media Rendering Using Density Octrees", International Association for Development of the Information Society, Volume 9, No. 2, pp. 96-114 (2014)
In order for computer generated imagery to recreate the characteristic visual appearance of phenomena such as smoke and fog it is necessary to compute the way in which light interacts with participating media. In this work we present a novel technique for computing volumetric single scattering lighting solutions for particle-based inhomogeneous participating media data sets. We seek to calculate volumetric lighting solutions for particle-based data sets as such data sets have the advantage of being spatially unbounded and relatively unrestricted with regard to memory as compared to uniform grids. In order to perform the calculations which are required for computing such a lighting solution, we introduce a novel octree based data structure. We refer to this new data structure as a density octree. The design of the density octree allows for efficiently computing light attenuation throughout the spatial extent. Using our data structure, we are able to produce high quality output imagery of arbitrary particle data sets in the presence of arbitrary numbers of lights. Read More
Heider K. Ali, Anthony D. Whitehead. "Feature Matching for Aligning Historical and Modern Images", International Journal of Computers and Their Applications, Volume 21, No. 3, pp. 188-201 (2014)
Provision of historical information based on geographical location represents a new scope of connecting the present of a certain location or landmark with its history through a timescape panorama. This may be achieved by exploring a linear timeline of photos for certain areas and landmarks that have both historic and modern photos. Matching modern to historical images requires a special effort in the sense of dealing with historical photos which were captured by photographers of different skills using cameras from a wide range of photographic technology eras. While there are many effective matching techniques which are vector- or binary- based that perform effectively on modern digital images, they are not accurate on historic photos. Read More
Anthony Whitehead. "Gesture Recognition with Accelerometers for Game Controllers, Phones and Wearables” Global Science and Technology Forum Journal on Computing, Volume 3, Number 4. (2014)
Hidden Markov Models have been effectively used in time series based pattern recognition problems in the past. T-20111his work explores using Hidden Markov Models (HMM) to do 3D gesture recognition from accelerometer data. Our work dif-fers from much of the previous work in that we examine the use of discreet HMMs rather than continuous HMMs. An interesting side effect of this is that method is therefore theoretically trans-portable to other devices that have a 3D sensor output system. In essence this brings us a mechanism to use the HMM model across a series of different sensor devices for gesture recognition. We achieve recognition results with accuracy rates approaching 90 percent for users who are not in the training samples. The speed of our system is also of interest as we are able to classify gestures at a rate of several hundred times per second. Read More
Ellis, J., Parush, A., Taing, M., Campbell, C., Chiu, C., Eldred, S., Whitehead, A., Irwin, D., Vaillancourt, R., Martelli, B., Voscamp, D., Elliott-Miller, P., Farion, K., "Preventing medication errors with high alert drugs: Testing the iDoseCheck", Canadian Journal of Nursing Informatics, Volume 7, Number 1 (2012).
M. M. Fouad, R. M. Dansereau, and A. D. Whitehead. "Image Registration Under Illumination Variations Using Region-based Huber’s M-estimator”, IEEE Transactions in Image Processing, Vol 21, No 3, pp. 1046-1060. (2012)
Obesity has fast become one of the leading preventable causes of death plaguing industrialized society, with increasing incidence among adults and children. It is viewed as one of the most serious public health epidemics of the 21st century (Barness et. al, 2007). The physical benefits of leading an active lifestyle are undeniable when combating this disease. Children are especially vulnerable to these diseases due to their increasingly sedentary lifestyles. The success of the Nintendo Wii as a fun way of promoting physical activity among all age groups has sparked an outpouring of more physically active games (or "exergames”) being introduced to the market, along with competitor consoles (Hawn, 2009). Read More
M. M. Fouad, R. M. Dansereau, A. D. Whitehead. "Geometric Image Registration Under Arbitrarily-Shaped Locally Variant Illuminations”, Journal of Signal, Image and Video Processing, Springer, Volume 6, Issue 4, pp 521-532, 2012 doi:10.1007/s11760-010-0178-4
In geometric image registration, illumination variations that exist between image pairs tend to degrade the precision of the registration, which can negatively affect subsequent processing. In this paper, we present a model to improve the sub-pixel geometric registration precision of image pairs when there exists locally variant illuminations with arbitrary shape. This model extends on our previous work to include multiple local shading levels of arbitrary shape, where the ill-posed problem is conditioned by constraining the solution to an estimated number of shading levels. The proposed model is solved using leastsquares estimation and is cast in an iterative coarse-to-fine framework, which allows a convergence rate that is similar to competing intensity-based image registration approaches. Read More
K. Fox, A. Whitehead. "3-D Pose Presentation for Training Applications”, Interactive Technology and Smart Education, Vol. 08, No. 04, pp. 249-262, (2011)
In this paper, we present a registration approach for images having arbitrarily-shaped locally variant illuminations. These variations tend to degrade the performance of geometric registration precision (GRP) and impact subsequent processing. Traditional registration approaches typically use a least-squares estimator that is sensitive to outliers. Instead, we propose using a robust bisquare M-estimator, as it differently penalizes the small and large residuals. The proposed approach shows clear improvements over competing approaches in terms of GRP and illumination correction, using simulated and real image pairs. Read More
H. Johnston, A. Whitehead. "Pose Presentation for a Dance-Based Massively Multiplayer Online Exergame”, International Journal of Entertainment Computing, Special Issue on Serious Games. Volume 2, Issue 2, pp 89-96, June 2011
A sedentary lifestyle is linked to many health problems, including diabetes, heart disease, and obesity. Active games attempt to offer a solution by encouraging players to be more physically active through the use of entertaining media. We present a framework for a massively multiplayer online exergame (MMOE), that combines elements of persuasive technology and massively multiplayer online games to provide players with a customized, social gaming experience with the potential for long-term engagement and measurable physical benefits. We then examine our own exergaming system, sensor network for active play (SNAP), to assess its suitability in an MMOE context Read More
A. Whitehead, H. Johnston, K. Fox, N. Crampton, J. Tuen. "Homogeneous Accelerometer-Based Sensor Networks for Game Interaction” In Computers in Entertainment, Volume 9 (1), art. no. 1. April 2011, Computers in Entertainment, Vol. 9, No. 1, April 2011. doi:10.1145/1953005.1953006
We have created and tested a wearable sensor network that detects a user’s body position and motion as input for interactive applications. It is envisioned to take game experiences such as Dance Dance Revolution, Wii Fit, and other active play scenarios to a whole new level, augmenting or replacing the binary foot-pad and balance board with a more immersive, full-body input system. We describe the design and functionality of the sensor network to characterize and verify body pose and position, perform experiments, and report on the capabilities and limitations of such a system. Our experience shows that a distributed set of sensors around the body prevents the player from cheating the system by using motion of the device alone to trick the system. Read More
A. Whitehead, R. Laganière, P. Bose. "Formalization of the General Video Temporal Synchronization Problem” Electronic Letters on Computer Vision and Image Analysis. Volume 9, Number 1, pp 1-17. May 2010
In this work, we present a theoretical formalization of the temporal synchronization problem and a method to temporally synchronize multiple stationary video cameras with overlapping views of the same scene. The method uses a two stage approach that first approximates the synchronization by tracking moving objects and identifying curvature points. The method then proceeds to refine the estimate using a consensus based matching heuristic to find frames that best agree with the pre-computed camera geometries from stationary background image features. By using the fundamental matrix and the trifocal tensor in the second refinement step, we improve the estimation of the first step and handle a broader more generic range of input scenarios and camera conditions. Read More
F. Sebastian, A. Whitehead. "Reflections on Interactive Museum Application Design and Development”, Design Principles and Practices: An International Journal, Volume 4, Issue 1. pp.453-464, May 2010
The design of interactive museum exhibits presents an interesting set of design issues above and beyond the typical technical and artistic design issues. The fact that the setting has an educational intent yet must also be free of tedium makes choices of medium interesting, if not difficult. In this work we present our experiences and findings of the design constraints that arose during our development of a interactive museum exhibit that was, effectively, an historical simulation. Read More
A. Whitehead and G. Roth, "Estimating Intrinsic Camera Parameters from the Fundamental Matrix using Evolutionary Algorithms", EURASIP Journal on Signal and Image Processing. Volume 2004, Issue 8. pp 1113-1124. 2004
Calibration is the process of computing the intrinsic (internal) camera parameters from a series of images. Normally calibration is done by placing predefined targets in the scene or by having special camera motions, such as rotations. If these two restrictions do not hold, then this calibration process is called autocalibration because it is done automatically, without user intervention. Using autocalibration, it is possible to create 3D reconstructions from a sequence of uncalibrated images without having to rely on a formal camera calibration process. Read More
Book Chapters
A. Whitehead, P. Bose, R. Laganière, "TRECVID 2006 NOTEBOOK PAPER: Feature based cut detection with automatic threshold selection”. NIST TRECVID Workshop (TRECVID'06), Gaithersburg, MD, USA, Nov. 13-14, 2006
There has been much work concentrated on creating accurate shot boundary detection algorithms in recent years. However a truly accurate method of cut detection still eludes researchers in general. In this work we present a scheme based on stable feature tracking for inter frame differencing. Furthermore, we present a method to stabilize the differences and automatically detect a global threshold to achieve a high detection rate. We compare our scheme against other cut detection techniques on a variety of data sources that have been specifically selected because of the difficulties they present due to quick motion, highly edited sequences and computer-generated effects. Read More
A. Whitehead, P. Bose, R. Laganière. "Feature based cut detection with automatic threshold selection”. Lecture Notes in Computer Science, Volume 3115, 2004, pp 410-418. ISBN 3-540-22539-0
Our approach is based on feature tracking where cuts are detected when only few features can be tracked across frame pairs. This unique criterion was found sufficient to detect most cuts in most videos even in the case of short term transitions. Furthermore, we propose a method to stabilize the differences and automatically identify a global threshold to achieve a high detection rate. Read More
A. Whitehead, G. Roth. "Evolutionary Based Autocalibration From the Fundamental Matrix", Lecture Notes in Computer Science, Volume 2279 , 2002, pp 292-303. ISBN 3-540-43378-3
We describe a new method of achieving autocalibration that uses a stochastic optimization approach taken from the field of evolutionary computing and we perform a number of experiments on standardized data sets that show the effectiveness of the approach. The basic assumption of this method is that the internal (intrinsic) camera parameters remain constant throughout the image sequence, i.e. they are taken from the same camera without varying the focal length. We show that for the autocalibration of focal length and aspect ratio, the evolutionary method achieves comparable results without the implementation complexity of other methods. Read More
Conference/Workshop
R. Verbickas, A. Whitehead, "Sky and Ground Detection Using Convolutional Neural Networks", In Proceedings of the International Conference on Machine Vision and Machine Learning, Prague, Czech Republic, August, 2014
A critical first step in navigation of unmanned aerial vehicles is the detection of the horizon line. This information can be used for adjusting flight parameters, attitude estimation as well as obstacle detection and avoidance. In this paper, a fast and robust technique for precise detection of the horizon is presented. Our approach is to apply convolutional neural networks to the task, training them to detect the sky and ground regions as well as the horizon line in flight videos. Thorough experiments using large datasets illustrate the significance and accuracy of this technique for various types of terrain as well as seasonal conditions. Read More
R. Monette, A. Whitehead. "Volumetric Rendering of Participating Media”, In proceedings Games and Entertainment Technologies Conference. July 2014, Lisbon, Portugal. Best Paper Award
In order for computer generated imagery to recreate the characteristic visual appearance of phenomena such as smoke and fog it is necessary to compute the way in which light interacts with participating media. In this work we present a novel technique for computing volumetric single scattering lighting solutions for particle based non-homogeneous participating media data sets. We seek to calculate volumetric lighting solutions for particle based data sets as such data sets have the advantage of being spatially unbounded and relatively unrestricted with regard to memory as compared to uniform grids. In order to perform the calculations which are required for computing such a lighting solution, we introduce a novel octree based data structure. We refer to this new data structure as a density octree. Read More
M. Zaczynski, A. Whitehead. "Establishing Design Guidelines in Interactive Exercise Gaming: Preliminary Data from Two Posing Studies”, Proceedings of ACM CHI 2014 Conference on Human Factors in Computing Systems, April 2014, Toronto, Canada
Interactive gaming has demonstrated promise as a low-cost, at-home training and fitness instruction alternative. However, commercially available systems today are designed primarily for entertainment. As a result, the quality of instruction delivery and level of involvement may not meet the needs of a user. This paper examines several issues including adapting for occlusion and lack of visibility; learning and orientation; and providing feedback to develop a set of design recommendations. Read More
H. Ali, A. Whitehead. "Modern to Historic Image Matching: ORB/SURF An Effective Matching Technique”, In proceedings of Computers and Their Applications Conference (CATA), March 2014, Las Vegas, USA
Matching modern to historical images requires a special effort in the sense of dealing with historical photos. While there are many robust matching techniques which are vector- or binary-based that perform effectively on modern images, they are not accurate on historic photos. Photos of different landmarks were gathered for a long timeline taken in different conditions of illuminations, position, and weather. Images were matched using standard vector-based matching techniques SIFT and SURF and a binary-based technique: ORB. Match results of these sets of images were recorded and analyzed. Read More
L. Stephenson, A. Whitehead "Distributed Multimodal Interaction Protocol”, In proceedings, International Conference on Multimedia and Human Computer Interaction, May 2013, Toronto, Canada
This paper introduces a novel networking protocol, distributed multimodal interaction protocol (DMIP) designed to alleviate development effort by providing a standard method to define and negotiate interaction modalities between networked, distributed systems, and by pushing application logic and layout to server side services. To evaluate the protocol, software layers were written to implement the protocol specification. On the endpoint providing the service, an additional layer was created to implement common application functionality. This layer, or service application programming interface (API) was then used to create a variety of applications. Read More
A. Whitehead, J. Opp. "Putting History in Your Hip Pocket”, In proceedings of Computers and Their Applications Conference (CATA), March 2013, Hawaii, USA
In this work we discuss our efforts to use the ubiquity of smart phone systems and the mobility they provide to stream historical information about your current place on the earth to the end user. We propose the concept of timescapes to portray this historical significance of where they are standing and allow a brief travel through time. By combining GPS location, with a rich media interpretation of existing historical documents, historical facts become an on-demand resource available to travellers, school children, historians and any interested 3rd party. To our knowledge this is the first introduction of the term timescape to be used in the context of historical information pull. Read More
Ellis, Parush, Campbell, Chiu, Eldred, Whitehead, Irwin, Vaillancourt, Rigby, Ferris, Martelli, Voskamp, Elliott-Miller, Farion. Preventing medication errors with high alert drugs: Phase 1 & 2 testing of the iDoseCheck. International Forum on Quality and Safety in Healthcare, Paris, France, April (2012)
Dosing errors are the most common type of pediatric drug errors, with over-dose outnumbering under-dose errors. Weight-based calculations are essential for proper dosing but complex in pediatric settings where patient weights may vary from 0.5 kg for a premature newborn to over 100 kg for an obese adolescent. A computer application called iDoseCheck (iDC) was developed to assist nurses in the calculation and verification component of the double check for administering intravenous morphine. The purpose of this study was to assess whether a graphic dose calculator, in comparison to standard paper/pencil and calculator (PPC), can support the double check process and reduce the rate of potential errors with high alert drugs. Read More
N.S. Boroujeni, S. A. Etemad, A. Whitehead. "'Fast Obstacle Detection Using Targeted Optical Flow'”, In proceedings of the International Conference on Image Processing (ICIP), Sept 2012, Florida
This paper presents a new method for obstacle detection using optical flow. The method employs a highly efficient and accurate adaptive motion detection algorithm for determining the regions in the image which are more likely to contain obstacles. These regions then have optical flow performed on them. We call this method targeted optical flow. Targeted optical flow performs significantly faster compared to regular optical flow. We employ two types of optical flow to demonstrate the performance and speed increase of the proposed system. Finally, k-means clustering is employed for obstacle reconstruction. The system is designed for color videos for better performance. Several benchmark and recorded sequences have been used for testing the system Read More
N.S. Boroujeni, S. A. Etemad, A. Whitehead. "Robust Horizon Detection using Segmentation for UAV Applications”, In proceedings of the Canadian Conference on Computer and Robot Vision (CRV), May 2012, Toronto, Ontario, Canada
A critical step in navigation of unmanned aerial vehicles is the detection of the horizon line. This information can be used for adjusting flight parameters as well as obstacle avoidance. In this paper, a fast and robust technique for precise detection of the horizon path is proposed. The method is based on existence of a unique light field that occurs in imagery where the horizon is viewed. This light field exists in different scenes including sea-sky, soil-sky, and forest-sky horizon lines. Our proposed approach employs segmentation of the scene and subsequent analysis of the image segments for extraction of the mentioned field and thus the horizon path. Read More
M. M. Fouad, R. M. Dansereau, and A. D. Whitehead, "Two-step super-resolution technique using bounded total variation and bisquare M-estimator under local illumination changes," in Proc. of IEEE Intern. Conf. on Image Processing (ICIP'2011, Brussels), September 11-14, 2011, pp. 1381-1384
In this paper, we present a super-resolution (SR) technique for images having arbitrarily-shaped local illumination changes. These variations tend to degrade the performance of the image registration, and hence impact the SR image reconstruction. Conventional SR techniques focus on enhancing the reconstruction step assuming aligned images. In this paper, we exploit our recent registration approach of images having illumination variations using a robust bisquare M-estimation. Then, we extend a bounded total variation-based approach for upsampling single frames to super-resolving multi-frames in order to reconstruct the unknown high-resolution (HR) frame. Read More
Ellis, J., Parush, A., Taing, M., Eldred, S., Campbell, C., Chu, C., Vaillancourt, R., Whitehead, A., Ferris, J., Martelli, B., Eliott-Miller, P., Irwin, D., Voscamp, Farion, K. "Preventing pediatric medication errors for IV morphine: evaluating a computerized double check tool for nurses”. Canadian Association of Pediatric Health Centers (CAPHC) annual conference, Ottawa, ON, October (2011)
K. Fox, A. Whitehead. "Effective Pose Presentation & Demonstration in Exergames”, In proceedings Games and Entertainment Technologies Conference. July 2011, Rome, Italy. Best Paper Award
Immersive, full-body active games are gaining popularity in the industry as both a form of entertainment, and a contributing aid in combating the numerous health problems faced by our increasingly obese society through physical activity. In our experience, the biggest issue with active pose-based games is the difficulty in effectively communicating a 3-dimensional pose to a user to facilitate a thorough understanding for accurate pose replication. In a traditional setting, like a yoga class, a physically present moderator would provide coaching to participants who struggled with pose reproduction. However, for obvious reasons, this cannot be implemented in a computer-based training setting. In this work, we present potential methods of providing visual feedback to end users in an effort to effectively and accurately communicate full-body poses for user-replication, without the need for a physically-present coach or moderator. Read More
J. Kuzub, Y. Mebarki, A Whitehead. "Improved Pressure Sensitive Paint Measurement Using Natural Feature Tracking and Piecewise Linear Resection”, In proceedings of the Canadian Conference on Computer and Robot Vision (CRV), May 2011, St. John, Nfld, Canada. Best Paper Award *
Wind tunnel Pressure Sensitive Paint (PSP) ratio techniques require accurate registration between wind-on and wind-off camera image pairs. The Piecewise Linear Resection (PLR) method of removing registration due to physical wind tunnel model motion and deformation errors can account for nonlinear deformations and benefits from increased tracking point coverage in the image. This work presents a method to increase the accuracy of PLR by tracking natural features in addition to standard fiducial markers. This is accomplished with Speeded-Up Robust Features (SURF) and a modified disparity gradient filtering technique. Read More
Straznicky, P.V., Ferguson, S., Belanger, F., Samson, C., Ahmadi, M., Goubran,R., Pearce, T., de Ruiter, A., Scaini, C., Whitehead, A., Laliberte, J., 2011, "Development of the GeoSurv II Unmanned Aircraft System (UAS)”, Canadian Exploration Geophysics Society (KEGS), Ottawa Chapter, 19 April 2011
M. M. Fouad, R. M. Dansereau, and A. D. Whitehead, "Image registration under local illumination variations using robust bisquare M-estimation," in Proc. of IEEE Intern. Conf. on Image Pro-cessing (ICIP'2010, Hong Kong), September 26-29, 2010, pp. 917-920.
In this paper, we present a registration approach for images having arbitrarily-shaped locally variant illuminations. These variations tend to degrade the performance of geometric registration precision (GRP) and impact subsequent processing. Traditional registration approaches typically use a least-squares estimator that is sensitive to outliers. Instead, we propose using a robust bisquare M-estimator, as it differently penalizes the small and large residuals. Read More
A. Whitehead, H. Johnston, J. Welch, N. Nixon. "Designing Effective Exergames”, ACM SIG-GRAPH Symposium on Video Games, Los Angeles, California, July 2010
A sedentary lifestyle is linked to many diseases, including diabetes and heart disease, as well as ailments such as obesity, which is becoming the major root cause of early death in most industrialized countries. The advent of the television, computers and videogames has resulted in a more sedentary lifestyle, with more time spent in front of a screen more than ever before. Exergaming is a term used to describe video games that provide encouragement to exercise, particularly for an audience that may be reluctant to engage in the more traditional forms of exercise. Exergames are a commonly accepted method of encouraging more physical activity to promote better health for those with high levels of sedentary screen time. In this work, we survey a number of quantitative exergame studies to define a general set of elements that make exergames effective from a physical standpoint. Read More
H. Johnston, A. Whitehead. "Designing a Customizable Dance Pose Creation System for a Mas-sively Multiplayer Online Exergames”, In Proceedings of the International Workshop on Serious Games Development and Applications, Derby, England, July 2010
M. M. Fouad, R. M. Dansereau, and A. D. Whitehead, "Geometric image registration under local-ly variant illuminations using Huber M-estimator," in A. Elmoataz et al. (Eds.): ICISP 2010, LNCS 6134, pp. 10-18. Springer, Heidelberg, 2010
In this paper, we extend our previous work on presenting a registration model for images having arbitrarily-shaped locally variant illuminations from shadows to multiple shading levels. These variations tend to degrade the performance of geometric registration and impact subsequent processing. Often, traditional registration models use a leastsquares estimator that is sensitive to outliers. Instead, we propose using a robust Huber M-estimator to increase the geometric registration accuracy (GRA). We demonstrate the proposed model and compare it to other models on simulated and real data. This modification shows clear improvements in terms of GRA and illumination correction. Read More
G. Treen, A. Whitehead. "A PCA-Based Binning Approach for Matching to Large SIFT Data-bases”, In Proc. of the Canadian Conference on Computer and Robot Vision (CRV), May 2010, Ottawa, Ontario, Canada . Best Paper Award
A method for efficiently finding SIFT correspondences in large keypoint archives by separating a database into bins - using the principal components of the SIFT descriptor vector as the binning criteria - is proposed. This technique builds upon our previous efforts to improve SIFT matching speed in image pairs, and will find correspondences approximately three times faster than FLANN - the approximate nearest-neighbor search library that implements the existing state of the art - for the same recall-precision performance. Read More
G. Treen, A. Whitehead. "More Efficient SIFT Matching from Keypoint Descriptor Properties”, IEEE Workshop on Applications of Computer Vision. Dec, 2009. (36%)
A modular approach to finding fast SIFT correspondences in single-image matching applications is proposed. Our algorithm exploits properties of the SIFT descriptor vector to find shortcuts to the most likely matches in a feature set. We are able to converge approximately 15 times faster than both PCA-SIFT and SURF (both of which use descriptor vectors that contain far fewer dimensions than SIFT), at near-equivalent recall and precision performance. Read More
M. M. Fouad, R. M. Dansereau, and A. D. Whitehead. "Geometric Image Registration Under Ar-bitrarily-Shaped Locally Variant Illumination and Occlusions”, IEEE International Conference on Image Processing, Nov 2009. (44% for all pres. types)
In geometric image registration, illumination variations that exist between image pairs tend to degrade the precision of the registration, which can negatively affect subsequent processing. In this paper, we present a model to improve the sub-pixel geometric registration precision of image pairs when there exists locally variant illuminations with arbitrary shape. This model extends on our previous work to include multiple local shading levels of arbitrary shape, where the ill-posed problem is conditioned by constraining the solution to an estimated number of shading levels. Read More
A. Whitehead, K. Fox. "Device Agnostic 3D gesture recognition using Hidden Markov Models”, In P roc. ACM Futureplay, May 2009. (35%)
Hidden Markov Models have been effectively used in pattern recognition systems in the past. In this work, we identify the necessary elements to successfully use an HMM system for 3D gesture recognition regardless of the sensor device being used. So long as the sensor system itself is capable of outputting information about the 3 axes of motion (X, Y, and Z), that information can be used in this generic model for accurate, high speed gesture recognition. The proposed system works with accelerometer data, positional data and gyro data alike Read More
H. Johnston, A. Whitehead. "Distinguishing Games, Serious Games, and Training Simulators on the Basis of Intent”, In Proc. ACM Futureplay, May 2009. (20%)
What’s the difference between a game, a serious game and a training simulator? Unfortunately we don’t have a zippy punch line for you, but in this work we present a means to segregate the three on the basis of user intent and the closeness to their reality, rather than the intent of the designer. We use analogies to older educational media and their classification to illustrate our point. Read More
A. Whitehead, F. Sebastian, "It’s All Greek to Me… A Case for the Classics in Videogame orient-ed curriculum”, In Proc. ACM FuturePlay, Nov 2008. (36%)
This article provides an overview of Classical Greek literature as a parallel for the game development industry: we outline how the historical developments of Greek storytelling and literature inform the developmental history of video games. As the Greek storytelling medium evolved, the sense of the tragic hero and narrative complexity evolved. Similarly, as generations of video game players evolve, their demand for more complex characters and more fully developed storylines will also evolve. We attempt to provide a vantage point that future game designers may consider during the design of future game-based story elements Read More
A. Whitehead, H. Johnston, N. Crampton, K. Fox, "Sensor Networks as Video Game Input De-vices ", In Proceedings of ACM Futureplay, Nov 2007. (~35%)
In this work we are motivated by creating a network of sensors that can be used as input devices for video games. Our goal is to create an inexpensive network of off-the-shelf sensors that are used to force proper movement and engagement of the player. Our experience shows that a distributed set of sensors around the body prevents the player from cheating the system by using motion of the device alone to trick the system. In this work we show that a relatively simple sensor network configuration can enforce proper form and ensure that the player is actively participating in the game context. Read More
N. Crampton, K. Fox, H. Johnston, A. Whitehead. "Dance, Dance Evolution: Accelerometer Sensor Networks as Input to Video Games", Haptic, Audio, Visual Environments and Games Oc-tober 2007
We have created and tested a wearable sensor network that detects a user's body position as input for video game applications. It is envisioned to take video game experiences such as Dance Dance Revolution to a whole new level, replacing the binary foot-pad with a more immersive, full-body input system. We describe the design and functionality of the sensor network and experiment with Mahalanobis distance as a nearest-neighbour means of classification. Results from our experiments with distance threshold levels, combined data sets and the effects of practice on user success rates are discussed. Read More
A. Whitehead, F. Sebastian, "Video Games: The Educational Tool to Harmonize Pedagogical Dif-ference”, In Proc. ACM FuturePlay, Nov 2006. (~35%)
This article presents an overview of how game technologies fit into the different learning models utilized by public educators. We expand on the work of Kafai who views two methods of game-based learning: instructionist and construction-ist methodologies. We claim that there exist significant sub-categories to this grouping that also divide by the learning strategy employed. We show that while there has been much work in utilizing video games for some styles of learning, other learning strategies have gone completely unvisited by game developers. We also explore that this lack of coverage is usually due to the complexities these learning strategies create or due to an inability to create the relationships with knowledge that naturally fit into a video game concept. Read More
E. Hahn, A. Whitehead, P. Bose, "Persistence in Dynamically Generated Environments", ACM SIGGRAPH Symposium on Video Games, July 2006. (22%)
A novel approach to generate virtual building interiors in real-time is presented. The interiors are generated in a top-down fashion using architectural guidelines. Although a building interior in its entirety may be quite large, only the portions that are needed immediately are generated. This lazy generation scheme allows the use of only a fraction of the memory that a model of the entire interior would otherwise require. Our method provides real-time frame rates, making it attractive for realtime interactive applications. Read More
E. Hahn, P. Bose, A. Whitehead "Lazy Generation of Building Interiors in Real-time",19th Cana-dian Conference on Electrical and Computer Engineering, pp. 2406-2409 May 2006
A novel approach to generate virtual building interiors in real-time is presented. The interiors are generated in a top-down fashion using architectural guidelines. Although a building interior in its entirety may be quite large, only the portions that are needed immediately are generated. This lazy generation scheme allows the use of only a fraction of the memory that a model of the entire interior would otherwise require. Our method provides real-time frame rates, making it attractive for realtime interactive applications. Read More
A. Whitehead. "Towards the Elimination of Steganographic Communication”, Third Annual Con-ference on Privacy, Security, and Trust. October 2005. (38%)
There have been a number of steganography embedding techniques proposed over the past few years. In turn, there has been great interest in steganalysis techniques as the embedding techniques improve. Specifically, universal steganalysis techniques have become more attractive since they work independently of the embedding technique. In this work, we examine the effectiveness of a basic universal technique that relies on some knowledge about the cover media, but not the embedding technique. We examine images as a cover media, and examine how a single technique that we call steganographic sanitization performs on 26 different steganography programs that are publicly available on the Internet. Our experiments are completed using a number of secret messages and a variety of different levels of sanitization. Read More
A. Whitehead, P. Bose, V. Audet. "High-speed, Texture Preserving Digital Image Inpainting”, The Seventh International Conference on Signal and Image Processing, August 2005
A. Whitehead, T. Quaife. "The Role of Public Terminal Administrators in Securing Cyber-Infrastructure”, IEEE Workshop on Cyber Infrastructure -- Emergency Preparedness Aspects April, 2005
A. Whitehead, R. Laganiere, P. Bose. "Synchronization of Multiple Video Sequences in Theory and in Practice”, IEEE Workshop on Applications of Computer Vision, Breckenridge, Colorado, January 2005. (19%)
In this work, we present a formalization of the video synchronization problem that exposes new variants of the problem that have been left unexplored to date. We also present a novel method to temporally synchronize multiple stationary video cameras with overlapping views that: 1) does not rely on certain scene properties, 2) suffices for all variants of the synchronization problem exposed by the theoretical disseration, and 3) does not rely on the trajectory correspondence problem to be solved apriori. The method uses a two stage approach that first approximates the synchronization by tracking moving objects and identifying inflection points. Read More
A. Whitehead "Fast Feature Based Video Segmentation and Annotation”, In proceedings Interna-tional Symposium on Signal Processing and it Applications (ISSPA), Paris, France, July 2003
In this paper, we present a method of segmenting video to detect cuts with accuracy equal to or better than both histogram and other feature based methods. As well, the method is faster than other feature based methods. By utilizing feature tracking on corners, rather than lines, we are able to reliably detect features such as cuts, fades and salient frames. Experimental evidence shows that the method is able to withstand high motion situations better than existing methods. Initial implementations using full sized video frames are able to achieve processing rates of 10-30 frames per second depending on the level of motion and number of features being tracked; this includes the time to generate the MPEG decompressed frames. Read More
V. Audet, P. Bose, D. Nussbaum, J. Sack, J. Szanto2, A. Whitehead. "Automatic seed detection in on-line portal images for prostate treatment", Visualization, Imaging and Image Processing (VIIP) conference proceedings, Malaga, Spain, Sept 2002
G. Roth and A. Whitehead. "Some Improvements on Two Autocalibration Algorithms from the Fundamental Matrix", International Conference on Pattern Recognition (ICPR'2002) conference proceedings, Quebec City, Canada, Aug 2002. (20%)
Autocalibration algorithms based on the fundamental matrix must solve the problem of finding the flobal minimum of a cost function which has many local minima. We describe a new method of achieving this goal, which uses a stochastic optimization approach taken from the field of evolutionary algorithms. In theory, approaches that use the fundamental matrix for auto-calibration are inferior to those based on a projective reconstruction. We argue that in practice if we use this new stochastic optimization approach this is not true. Read More
A. Whitehead and G. Roth, "Evolutionary Based Autocalibration From the Fundamental Matrix", EvolASP Workshop proceedings, Springer-Verlag, Kinsale, Ireland, April 2002. Best Paper Award
We describe a new method of achieving autocalibration that uses a stochastic optimization approach taken from the field of evolutionary computing and we perform a number of experiments on standardized data sets that show the effectiveness of the approach. The basic assumption of this method is that the internal (intrinsic) camera parameters remain constant throughout the image sequence, i.e. they are taken from the same camera without varying the focal length. We show that for the autocalibration of focal length and aspect ratio, the evolutionary method achieves comparable results without the implementation complexity of other methods. Read More
A. Whitehead and G. Roth, "Salient Frame Extraction for Structure from Motion", Visualization, Imaging and Image Processing (VIIP) conference proceedings, pp 658-663, Marbella, Spain, Sept 2001
We propose a key frame extraction mechanism to aid the Structure from Motion (SfM) problem when dealing with image sequences from video cameras. Due to high frame rates (15 frames per second or more) the baseline between frames can be very small and the number of frames can become unpractical to deal with effectively. The mechanism described in this paper is a preprocessing step designed to make an ideal image sequence from larger sequence of video frame data. Based on a proven tracking mechanism, the algorithm remains quite simple yet effective for identifying and extracting salient frame data for the SfM problem in effect removing degeneracy cases. Read More
G. Roth and A. Whitehead. "Using projective vision to find camera positions in an image se-quence", In Proceedings Vision Interface (VI'2000) conference proceedings, pp. 87-94, Montreal, Canada, May 2000
The paradigm of projective vision has recently become popular. In this paper we describe a system for computing camera positions from an image sequence using pro- jective methods. Projective methods are normally used to deal with uncalibrated images. However, we claim that even when calibration information is available it is often better to use the projective approach. By computing the trilinear tensor it is possible to produce a reliable and accurate set of correspondences. When calibration information is available these correspondences can be sent directly to a photogrammetric program to produce a set of camera positions. We show one way of dealing with the problem of cumulative error in the tensor computation and demonstrate that projective methods can handle surprisingly large baselines, in certain cases one third of the image size. Read More
A. Whitehead and G. Roth, "The Projective Vision Toolkit", Modelling and Simulation (M.H. Hamza Ed) conference proceedings, Pittsburgh, Pennsylvania, pp204-209 May 2000
Projective vision research has recently received a lot of attention and has claimed some important results in current literature. In this paper, we present a compilation of tools that we have created to allow further research into the field. Not only can experienced projective vision researchers use these tools, but they also have use as a visual learning aid for those just undertaking the task of learning projective vision. We will discuss tools for computing interest points, correspondence matching, computing the fundamental matrix, computing the trilinear tensor, and our intent for future releases of the Projective Vision Toolkit(PVT). Read More
Patents
A. Whitehead and P. Morin, "Method and Device for Classifying Internet Objects and Objects Stored on Computer-Readable Media". Publication Date: April 2008
Conference Presentations
Campbell, C. Ellis, J. Parush. A, Whitehead, A. "Preventing Wrong Dose Morphine Errors: Test-ing the iDoseCheck”, Sick Kids Patient Safety Conference. Toronto. 2013. * Best Poster Award *
Campbell, C. Ellis, J. Parush. A, Whitehead, A. "Preventing Wrong Dose Morphine Errors: Test-ing the iDoseCheck”. 9th Annual Paediatric Patient Safety Symposium – Create the Culture: Leadership, Partnership and Infrastructure. 2013 * Best Paper Award *
Hueston, E, Parush, A, Whitehead, A, Garvey, T., "FUSE: Fire Update Support Engine (An Inte-grated Information Display for the Forest Fire Response Centre”. Wildland Fire Canada, Alberta, Canada, October, 2012
Campbell, C. Ellis, J. Parush. A, Whitehead, A. "Preventing medication errors for high alert drugs: Phase 1 testing of the iDoseCheck”. International Forum on Quality and Safety in Healthcare. Paris, France. April 2012
Campbell, C. Ellis, J. Parush. A, Whitehead, A. "Preventing Medication Errors with High Alert Drugs: Testing a Computerized Double Check”. 4th Annual CHEO (Children’s Hospital of Eastern Ontario) Research Day, Ottawa, ON, October, 2011
Campbell, C. Ellis, J. Parush. A, Whitehead, A. "Preventing Medication Errors with High Alert Drugs: Testing a Computerized Double Check”. Canadian Association for People-Centred Health. Ottawa, Ontario, Sept 2011
Straznicky, P., Samson, C., Ahmadi, M., Goubran, R., Pierce, T., Whitehead, A., and Ferguson, S. 2010. "Geosurv II Unmanned Aircraft System - A solution for geomagnetic airborne surveys". 3rd Joint CMOS-CGU (Canadian Meteorological and Oceanographic Society; Canadian Geophysical Union) Congress, Ottawa, ON, 31 May 31-4 June, 2010
A. Whitehead and F. Sebastian, "History or His-Story: Reflections on Interactive Museum Exhibit Design", International Design Conference 2010, Chicago, February, 2010
Demonstrations, Panels, Workshops, Artworks, Installations
Sensor Networks for Exergames CHI 2014
Public History Prize by the Canadian Historical Association, 2013 (peer reviewed)
*The award is given annually by the Canadian Historical Association to recognize a work that achieves high standards of original research, scholarship, and presentation; brings an inno-vative public history contribution to its audience; and serves as a model for future work, ad-vancing the field of public history in Canada*
Sensor Networks for Active Play Video Presentation. In E3, Indiecade booth. Los Angeles, Cali-fornia, June, 2009. (peer reviewed)
Game-Based Curriculum Development, Panel Chair, ACM FuturePlay, Toronto, Ontario, 2008.
EmoCapsule: An emotion oriented art installation. ACM SIGGRAPH, Los Angeles, California, 2008. (peer reviewed)
SNAP!: Sensor Networks for Active Play. ACM SIGGRAPH Sandbox: Symposium on Video Games. Los Angeles, California, 2008. (peer reviewed)
Video Games for pedagogical Harmonization. Eastern Ontario Symposium on Educational Tech-nology (EOSET), Ottawa, Ontario, 2008. (peer reviewed)
Harder Lessons " best practices in game-based education, Panelist, ACM FuturePlay, Toronto, On-tario, 2007.
Dance Dance Evolution: An experiment in pose based gaming. ACM FuturePlay, ToRonto, Ontar-io, 2007. (peer reviewed)