Paper in MICCAI (2015): “Automated Assessment of Surgical Skills Using Frequency Analysis”

October 6th, 2015 Irfan Essa Posted in Activity Recognition, Aneeq Zia, Eric Sarin, Mark Clements, Medical, MICCAI, Papers, Vinay Bettadapura, Yachna Sharma No Comments »

Paper

  • A. Zia, Y. Sharma, V. Bettadapura, E. Sarin, M. Clements, and I. Essa (2015), “Automated Assessment of Surgical Skills Using Frequency Analysis,” in International Conference on Medical Image Computing and Computer Assisted Interventions (MICCAI), 2015. [PDF] [BIBTEX]
    @InProceedings{    2015-Zia-AASSUFA,
      author  = {A. Zia and Y. Sharma and V. Bettadapura and E.
          Sarin and M. Clements and I. Essa},
      booktitle  = {International Conference on Medical Image Computing
          and Computer Assisted Interventions (MICCAI)},
      month    = {October},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Zia-AASSUFA.pdf}
          ,
      title    = {Automated Assessment of Surgical Skills Using
          Frequency Analysis},
      year    = {2015}
    }

Abstract

We present an automated framework for a visual assessment of the expertise level of surgeons using the OSATS (Objective Structured Assessment of Technical Skills) criteria. Video analysis technique for extracting motion quality via  frequency coefficients is introduced. The framework is tested in a case study that involved analysis of videos of medical students with different expertise levels performing basic surgical tasks in a surgical training lab setting. We demonstrate that transforming the sequential time data into frequency components effectively extracts the useful information differentiating between different skill levels of the surgeons. The results show significant performance improvements using DFT and DCT coefficients over known state-of-the-art techniques.

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Paper in ISWC 2015: “Predicting Daily Activities from Egocentric Images Using Deep Learning”

September 7th, 2015 Irfan Essa Posted in Activity Recognition, Daniel Castro, Gregory Abowd, Henrik Christensen, ISWC, Machine Learning, Papers, Steven Hickson, Ubiquitous Computing, Vinay Bettadapura No Comments »

Paper

  • D. Castro, S. Hickson, V. Bettadapura, E. Thomaz, G. Abowd, H. Christensen, and I. Essa (2015), “Predicting Daily Activities from Egocentric Images Using Deep Learning,” in Proceedings of International Symposium on Wearable Computers (ISWC), 2015. [PDF] [WEBSITE] [arXiv] [BIBTEX]
    @InProceedings{    2015-Castro-PDAFEIUDL,
      arxiv    = {http://arxiv.org/abs/1510.01576},
      author  = {Daniel Castro and Steven Hickson and Vinay
          Bettadapura and Edison Thomaz and Gregory Abowd and
          Henrik Christensen and Irfan Essa},
      booktitle  = {Proceedings of International Symposium on Wearable
          Computers (ISWC)},
      month    = {September},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Castro-PDAFEIUDL.pdf}
          ,
      title    = {Predicting Daily Activities from Egocentric Images
          Using Deep Learning},
      url    = {http://www.cc.gatech.edu/cpl/projects/dailyactivities/}
          ,
      year    = {2015}
    }

Abstract

Castro-ISWC2015We present a method to analyze images taken from a passive egocentric wearable camera along with the contextual information, such as time and day of a week, to learn and predict everyday activities of an individual. We collected a dataset of 40,103 egocentric images over a 6 month period with 19 activity classes and demonstrate the benefit of state-of-the-art deep learning techniques for learning and predicting daily activities. Classification is conducted using a Convolutional Neural Network (CNN) with a classification method we introduce called a late fusion ensemble. This late fusion ensemble incorporates relevant contextual information and increases our classification accuracy. Our technique achieves an overall accuracy of 83.07% in predicting a person’s activity across the 19 activity classes. We also demonstrate some promising results from two additional users by fine-tuning the classifier with one day of training data.

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Paper in IEEE WACV (2015): “Leveraging Context to Support Automated Food Recognition in Restaurants”

January 6th, 2015 Irfan Essa Posted in Activity Recognition, Computer Vision, Edison Thomaz, First Person Computing, Gregory Abowd, Mobile Computing, PAMI/ICCV/CVPR/ECCV, Papers, Ubiquitous Computing, Uncategorized, Vinay Bettadapura No Comments »

Paper

  • V. Bettadapura, E. Thomaz, A. Parnami, G. Abowd, and I. Essa (2015), “Leveraging Context to Support Automated Food Recognition in Restaurants,” in Proceedings of IEEE Winter Conference on Applications of Computer Vision (WACV), 2015. [PDF] [WEBSITE] [DOI] [arXiv] [BIBTEX]
    @InProceedings{    2015-Bettadapura-LCSAFRR,
      arxiv    = {http://arxiv.org/abs/1510.02078},
      author  = {Vinay Bettadapura and Edison Thomaz and Aman
          Parnami and Gregory Abowd and Irfan Essa},
      booktitle  = {Proceedings of IEEE Winter Conference on
          Applications of Computer Vision (WACV)},
      doi    = {10.1109/WACV.2015.83},
      month    = {January},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Bettadapura-LCSAFRR.pdf}
          ,
      publisher  = {IEEE Computer Society},
      title    = {Leveraging Context to Support Automated Food
          Recognition in Restaurants},
      url    = {http://www.vbettadapura.com/egocentric/food/},
      year    = {2015}
    }

 

Abstract

The pervasiveness of mobile cameras has resulted in a dramatic increase in food photos, which are pictures reflecting what people eat. In this paper, we study how taking pictures of what we eat in restaurants can be used for the purpose of automating food journaling. We propose to leverage the context of where the picture was taken, with additional information about the restaurant, available online, coupled with state-of-the-art computer vision techniques to recognize the food being consumed. To this end, we demonstrate image-based recognition of foods eaten in restaurants by training a classifier with images from restaurant’s online menu databases. We evaluate the performance of our system in unconstrained, real-world settings with food images taken in 10 restaurants across 5 different types of food (American, Indian, Italian, Mexican and Thai).food-poster

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Paper in WACV (2015): “Egocentric Field-of-View Localization Using First-Person Point-of-View Devices”

January 6th, 2015 Irfan Essa Posted in Activity Recognition, Caroline Pantofaru, Computer Vision, First Person Computing, Mobile Computing, PAMI/ICCV/CVPR/ECCV, Papers, Vinay Bettadapura No Comments »

Paper

  • V. Bettadapura, I. Essa, and C. Pantofaru (2015), “Egocentric Field-of-View Localization Using First-Person Point-of-View Devices,” in Proceedings of IEEE Winter Conference on Applications of Computer Vision (WACV), 2015. (Best Paper Award) [PDF] [WEBSITE] [DOI] [arXiv] [BIBTEX]
    @InProceedings{    2015-Bettadapura-EFLUFPD,
      arxiv    = {http://arxiv.org/abs/1510.02073},
      author  = {Vinay Bettadapura and Irfan Essa and Caroline
          Pantofaru},
      awards  = {(Best Paper Award)},
      booktitle  = {Proceedings of IEEE Winter Conference on
          Applications of Computer Vision (WACV)},
      doi    = {10.1109/WACV.2015.89},
      month    = {January},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Bettadapura-EFLUFPD.pdf}
          ,
      publisher  = {IEEE Computer Society},
      title    = {Egocentric Field-of-View Localization Using
          First-Person Point-of-View Devices},
      url    = {http://www.vbettadapura.com/egocentric/localization/}
          ,
      year    = {2015}
    }

Abstract

We present a technique that uses images, videos and sensor data taken from first-person point-of-view devices to perform egocentric field-of-view (FOV) localization. We define egocentric FOV localization as capturing the visual information from a person’s field-of-view in a given environment and transferring this information onto a reference corpus of images and videos of the same space, hence determining what a person is attending to. Our method matches images and video taken from the first-person perspective with the reference corpus and refines the results using the first-person’s head orientation information obtained using the device sensors. We demonstrate single and multi-user egocentric FOV localization in different indoor and outdoor environments with applications in augmented reality, event understanding and studying social interactions.

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Four Papers at IEEE Winter Conference on Applications of Computer Vision (WACV 2015)

January 5th, 2015 Irfan Essa Posted in Computational Photography and Video, Computer Vision, PAMI/ICCV/CVPR/ECCV, Papers, S. Hussain Raza, Steven Hickson, Vinay Bettadapura No Comments »

Four papers accepted at the IEEE Winter Conference on Applications of Computer Vision (WACV) 2015. See you at Waikoloa Beach, Hawaii!

  • V. Bettadapura, E. Thomaz, A. Parnami, G. Abowd, and I. Essa (2015), “Leveraging Context to Support Automated Food Recognition in Restaurants,” in Proceedings of IEEE Winter Conference on Applications of Computer Vision (WACV), 2015. [PDF] [WEBSITE] [DOI] [arXiv] [BIBTEX]
    @InProceedings{    2015-Bettadapura-LCSAFRR,
      arxiv    = {http://arxiv.org/abs/1510.02078},
      author  = {Vinay Bettadapura and Edison Thomaz and Aman
          Parnami and Gregory Abowd and Irfan Essa},
      booktitle  = {Proceedings of IEEE Winter Conference on
          Applications of Computer Vision (WACV)},
      doi    = {10.1109/WACV.2015.83},
      month    = {January},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Bettadapura-LCSAFRR.pdf}
          ,
      publisher  = {IEEE Computer Society},
      title    = {Leveraging Context to Support Automated Food
          Recognition in Restaurants},
      url    = {http://www.vbettadapura.com/egocentric/food/},
      year    = {2015}
    }
  • S. Hickson, I. Essa, and H. Christensen (2015), “Semantic Instance Labeling Leveraging Hierarchical Segmentation,” in Proceedings of IEEE Winter Conference on Applications of Computer Vision (WACV), 2015. [PDF] [DOI] [BIBTEX]
    @InProceedings{    2015-Hickson-SILLHS,
      author  = {Steven Hickson and Irfan Essa and Henrik
          Christensen},
      booktitle  = {Proceedings of IEEE Winter Conference on
          Applications of Computer Vision (WACV)},
      doi    = {10.1109/WACV.2015.147},
      month    = {January},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Hickson-SILLHS.pdf}
          ,
      publisher  = {IEEE Computer Society},
      title    = {Semantic Instance Labeling Leveraging Hierarchical
          Segmentation},
      year    = {2015}
    }
  • S. H. Raza, A. Humayun, M. Grundmann, D. Anderson, and I. Essa (2015), “Finding Temporally Consistent Occlusion Boundaries using Scene Layout,” in Proceedings of IEEE Winter Conference on Applications of Computer Vision (WACV), 2015. [PDF] [DOI] [BIBTEX]
    @InProceedings{    2015-Raza-FTCOBUSL,
      author  = {Syed Hussain Raza and Ahmad Humayun and Matthias
          Grundmann and David Anderson and Irfan Essa},
      booktitle  = {Proceedings of IEEE Winter Conference on
          Applications of Computer Vision (WACV)},
      doi    = {10.1109/WACV.2015.141},
      month    = {January},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Raza-FTCOBUSL.pdf}
          ,
      publisher  = {IEEE Computer Society},
      title    = {Finding Temporally Consistent Occlusion Boundaries
          using Scene Layout},
      year    = {2015}
    }
  • V. Bettadapura, I. Essa, and C. Pantofaru (2015), “Egocentric Field-of-View Localization Using First-Person Point-of-View Devices,” in Proceedings of IEEE Winter Conference on Applications of Computer Vision (WACV), 2015. (Best Paper Award) [PDF] [WEBSITE] [DOI] [arXiv] [BIBTEX]
    @InProceedings{    2015-Bettadapura-EFLUFPD,
      arxiv    = {http://arxiv.org/abs/1510.02073},
      author  = {Vinay Bettadapura and Irfan Essa and Caroline
          Pantofaru},
      awards  = {(Best Paper Award)},
      booktitle  = {Proceedings of IEEE Winter Conference on
          Applications of Computer Vision (WACV)},
      doi    = {10.1109/WACV.2015.89},
      month    = {January},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Bettadapura-EFLUFPD.pdf}
          ,
      publisher  = {IEEE Computer Society},
      title    = {Egocentric Field-of-View Localization Using
          First-Person Point-of-View Devices},
      url    = {http://www.vbettadapura.com/egocentric/localization/}
          ,
      year    = {2015}
    }

Last one was also the WINNER of Best Paper Award (see http://wacv2015.org/). More details coming soon.

 

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Paper in M2CAI 2014: “Video Based Assessment of OSATS Using Sequential Motion Textures”

September 14th, 2014 Irfan Essa Posted in Activity Recognition, Behavioral Imaging, Computer Vision, Medical, MICCAI, Papers, Thomas Ploetz, Vinay Bettadapura, Yachna Sharma No Comments »

Paper

  • Y. Sharma, V. Bettadapura, T. Ploetz, N. Hammerla, S. Mellor, R. McNaney, P. Olivier, S. Deshmukh, A. Mccaskie, and I. Essa (2014), “Video Based Assessment of OSATS Using Sequential Motion Textures,” in Proceedings of Workshop on Modeling and Monitoring of Computer Assisted Interventions (M2CAI), 2014. (Best Paper Honorable Mention Award) [PDF] [BIBTEX]
    @InProceedings{    2014-Sharma-VBAOUSMT,
      author  = {Yachna Sharma and Vinay Bettadapura and Thomas
          Ploetz and Nils Hammerla and Sebastian Mellor and
          Roisin McNaney and Patrick Olivier and Sandeep
          Deshmukh and Andrew Mccaskie and Irfan Essa},
      awards  = {(Best Paper Honorable Mention Award)},
      booktitle  = {{Proceedings of Workshop on Modeling and Monitoring
          of Computer Assisted Interventions (M2CAI)}},
      month    = {September},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2014-Sharma-VBAOUSMT.pdf}
          ,
      title    = {Video Based Assessment of OSATS Using Sequential
          Motion Textures},
      year    = {2014}
    }

Abstract

2014-Sharma-VBAOUSMTA fully automated framework for video-based surgical skill assessment is presented that incorporates the sequential and qualitative aspects of surgical motion in a data-driven manner. The Objective Structured Assessment of Technical Skills (OSATS) assessments is replicated, which provides both an overall and in-detail evaluation of basic suturing skills required for surgeons. Video analysis techniques are introduced that incorporate sequential motion aspects into motion textures. Significant performance improvement over standard bag-of-words and motion analysis approaches is demonstrated. The framework is evaluated in a case study that involved medical students with varying levels of expertise performing basic surgical tasks in a surgical training lab setting.

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Paper in ACM KDD 2013 “Detecting insider threats in a real corporate database of computer usage activity”

August 11th, 2013 Irfan Essa Posted in AAAI/IJCAI/UAI, Josh Jones, Vinay Bettadapura No Comments »

  • T. E. Senator, H. G. Goldberg, A. Memory, W. T. Young, B. Rees, R. Pierce, D. Huang, M. Reardon, D. A. Bader, E. Chow, I. Essa, J. Jones, V. Bettadapura, D. H. Chau, O. Green, O. Kaya, A. Zakrzewska, E. Briscoe, R. I. L. Mappus, R. McColl, L. Weiss, T. G. Dietterich, A. Fern, W. Wong, S. Das, A. Emmott, J. Irvine, J. Lee, D. Koutra, C. Faloutsos, D. Corkill, L. Friedland, A. Gentzel, and D. Jensen (2013), “Detecting insider threats in a real corporate database of computer usage activity,” in Proceedings of the 19th ACM SIGKDD international conference on Knowledge discovery and data mining, New York, NY, USA, 2013, pp. 1393-1401. [WEBSITE] [DOI] [BIBTEX]
    @InProceedings{    2013-Senator-DITRCDCUA,
      acmid    = {2488213},
      address  = {New York, NY, USA},
      author  = {Senator, Ted E. and Goldberg, Henry G. and Memory,
          Alex and Young, William T. and Rees, Brad and
          Pierce, Robert and Huang, Daniel and Reardon,
          Matthew and Bader, David A. and Chow, Edmond and
          Essa, Irfan and Jones, Joshua and Bettadapura, Vinay
          and Chau, Duen Horng and Green, Oded and Kaya, Oguz
          and Zakrzewska, Anita and Briscoe, Erica and Mappus,
          Rudolph IV L. and McColl, Robert and Weiss, Lora and
          Dietterich, Thomas G. and Fern, Alan and Wong,
          Weng--Keen and Das, Shubhomoy and Emmott, Andrew and
          Irvine, Jed and Lee, Jay-Yoon and Koutra, Danai and
          Faloutsos, Christos and Corkill, Daniel and
          Friedland, Lisa and Gentzel, Amanda and Jensen,
          David},
      booktitle  = {{Proceedings of the 19th ACM SIGKDD international
          conference on Knowledge discovery and data mining}},
      doi    = {10.1145/2487575.2488213},
      isbn    = {978-1-4503-2174-7},
      location  = {Chicago, Illinois, USA},
      month    = {September},
      numpages  = {9},
      pages    = {1393--1401},
      publisher  = {ACM},
      series  = {KDD '13},
      title    = {Detecting insider threats in a real corporate
          database of computer usage activity},
      url    = {http://doi.acm.org/10.1145/2487575.2488213},
      year    = {2013}
    }

Abstract

This paper reports on methods and results of an applied research project by a team consisting of SAIC and four universities to develop, integrate, and evaluate new approaches to detect the weak signals characteristic of insider threats on organizations’ information systems. Our system combines structural and semantic information from a real corporate database of monitored activity on their users’ computers to detect independently developed red team inserts of malicious insider activities. We have developed and applied multiple algorithms for anomaly detection based on suspected scenarios of malicious insider behavior, indicators of unusual activities, high-dimensional statistical patterns, temporal sequences, and normal graph evolution. Algorithms and representations for dynamic graph processing provide the ability to scale as needed for enterprise-level deployments on real-time data streams. We have also developed a visual language for specifying combinations of features, baselines, peer groups, time periods, and algorithms to detect anomalies suggestive of instances of insider threat behavior. We defined over 100 data features in seven categories based on approximately 5.5 million actions per day from approximately 5,500 users. We have achieved area under the ROC curve values of up to 0.979 and lift values of 65 on the top 50 user-days identified on two months of real data.

via ACM DL Detecting insider threats in a real corporate database of computer usage activity.

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Paper in IEEE CVPR 2013 “Augmenting Bag-of-Words: Data-Driven Discovery of Temporal and Structural Information for Activity Recognition”

June 27th, 2013 Irfan Essa Posted in Activity Recognition, Behavioral Imaging, Grant Schindler, PAMI/ICCV/CVPR/ECCV, Papers, Sports Visualization, Thomas Ploetz, Vinay Bettadapura No Comments »

  • V. Bettadapura, G. Schindler, T. Ploetz, and I. Essa (2013), “Augmenting Bag-of-Words: Data-Driven Discovery of Temporal and Structural Information for Activity Recognition,” in Proceedings of IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2013. [PDF] [WEBSITE] [DOI] [arXiv] [BIBTEX]
    @InProceedings{    2013-Bettadapura-ABDDTSIAR,
      arxiv    = {http://arxiv.org/abs/1510.02071},
      author  = {Vinay Bettadapura and Grant Schindler and Thomas
          Ploetz and Irfan Essa},
      booktitle  = {{Proceedings of IEEE Conference on Computer Vision
          and Pattern Recognition (CVPR)}},
      doi    = {10.1109/CVPR.2013.338},
      month    = {June},
      organization  = {IEEE Computer Society},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2013-Bettadapura-ABDDTSIAR.pdf}
          ,
      title    = {Augmenting Bag-of-Words: Data-Driven Discovery of
          Temporal and Structural Information for Activity
          Recognition},
      url    = {http://www.cc.gatech.edu/cpl/projects/abow/},
      year    = {2013}
    }

Abstract

We present data-driven techniques to augment Bag of Words (BoW) models, which allow for more robust modeling and recognition of complex long-term activities, especially when the structure and topology of the activities are not known a priori. Our approach specifically addresses the limitations of standard BoW approaches, which fail to represent the underlying temporal and causal information that is inherent in activity streams. In addition, we also propose the use of randomly sampled regular expressions to discover and encode patterns in activities. We demonstrate the effectiveness of our approach in experimental evaluations where we successfully recognize activities and detect anomalies in four complex datasets.

via IEEE Xplore – Augmenting Bag-of-Words: Data-Driven Discovery of Temporal and Structural Information for Activity R….

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AT UBICOMP 2012 Conference, in Pittsburgh, PA, September 5 – 7, 2012

September 4th, 2012 Irfan Essa Posted in Edison Thomaz, Grant Schindler, Gregory Abowd, Papers, Presentations, Thomas Ploetz, UBICOMP, Ubiquitous Computing, Vinay Bettadapura No Comments »

At ACM sponsored, 14th International Conference on Ubiquitous Computing (Ubicomp 2012), Pittsburgh, PA, September 5 – 7, 2012.

Here are the highlights of my group’s participation in Ubicomp 2012.

  • E. Thomaz, V. Bettadapura, G. Reyes, M. Sandesh, G. Schindler, T. Ploetz, G. D. Abowd, and I. Essa (2012), “Recognizing Water-Based Activities in the Home Through Infrastructure-Mediated Sensing,” in Proceedings of ACM International Conference on Ubiquitous Computing (UBICOMP), 2012. [PDF] [WEBSITE] (Oral Presentation at 2pm on Wednesday September 5, 2012).
  • J. Wang, G. Schindler, and I. Essa (2012), “Orientation Aware Scene Understanding for Mobile Camera,” in Proceedings of ACM International Conference on Ubiquitous Computing (UBICOMP), 2012. [PDF][WEBSITE] (Oral Presentation at 2pm on Thursday September 6, 2012).

In addition, my colleague, Gregory Abowd has a position paper on “What next, Ubicomp? Celebrating an intellectual disappearing act” on Wednesday 11:15am session and my other colleague/collaborator Thomas Ploetz has a paper on “Automatic Assessment of Problem Behavior in Individuals with Developmental Disabilities” with his co-authors Nils Hammerla, Agata Rozga, Andrea Reavis, Nathan Call, Gregory Abowd on Friday September 6, in the 9:15am session.

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