Paper in M2CAI (workshop MICCAI) on “Fine-tuning Deep Architectures for Surgical Tool Detection” and results of Tool Detection Challange

October 21st, 2016 Irfan Essa Posted in Aneeq Zia, Awards, Computer Vision, Daniel Castro, Medical, MICCAI No Comments »

Paper

  • A. Zia, D. Castro, and I. Essa (2016), “Fine-tuning Deep Architectures for Surgical Tool Detection,” in Workshop and Challenges on Modeling and Monitoring of Computer Assisted Interventions (M2CAI), Held in Conjunction with International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI), Athens, Greece, 2016. [PDF] [WEBSITE] [BIBTEX]
    @InProceedings{    2016-Zia-FDASTD,
      address  = {Athens, Greece},
      author  = {Aneeq Zia and Daniel Castro and Irfan Essa},
      booktitle  = {Workshop and Challenges on Modeling and Monitoring
          of Computer Assisted Interventions (M2CAI), Held in
          Conjunction with International Conference on Medical
          Image Computing and Computer Assisted Intervention
          (MICCAI)},
      month    = {October},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2016-Zia-FDASTD.pdf},
      title    = {Fine-tuning Deep Architectures for Surgical Tool
          Detection},
      url    = {http://www.cc.gatech.edu/cpl/projects/deepm2cai/},
      year    = {2016}
    }

Abstract

Visualization of some of the training videos.

Understanding surgical workflow has been a key concern of the medical research community. One of the main advantages of surgical workflow detection is real-time operating room (OR) scheduling. For hospitals, each minute of OR time is important in order to reduce cost and increase patient throughput. Traditional approaches in this field generally tackle the video analysis using hand-crafted video features to facilitate the tool detection. Recently, Twinanda et al. presented a CNN architecture ’EndoNet’ which outperformed previous methods for both surgical tool detection and surgical phase detection. Given the recent success of these networks, we present a study of various architectures coupled with a submission to the M2CAI Surgical Tool Detection challenge. We achieved a top-3 result for the M2CAI competition with a mAP of 37.6.

 

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Paper (ACM MM 2016) “Leveraging Contextual Cues for Generating Basketball Highlights”

October 18th, 2016 Irfan Essa Posted in ACM MM, Caroline Pantofaru, Computational Photography and Video, Computer Vision, Papers, Sports Visualization, Vinay Bettadapura No Comments »

Paper

  • V. Bettadapura, C. Pantofaru, and I. Essa (2016), “Leveraging Contextual Cues for Generating Basketball Highlights,” in Proceedings of ACM International Conference on Multimedia (ACM-MM), 2016. [PDF] [WEBSITE] [arXiv] [BIBTEX]
    @InProceedings{    2016-Bettadapura-LCCGBH,
      arxiv    = {http://arxiv.org/abs/1606.08955},
      author  = {Vinay Bettadapura and Caroline Pantofaru and Irfan
          Essa},
      booktitle  = {Proceedings of ACM International Conference on
          Multimedia (ACM-MM)},
      month    = {October},
      organization  = {ACM},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2016-Bettadapura-LCCGBH.pdf},
      title    = {Leveraging Contextual Cues for Generating
          Basketball Highlights},
      url    = {http://www.vbettadapura.com/highlights/basketball/index.htm},
      year    = {2016}
    }

Abstract

2016-Bettadapura-LCCGBH

Leveraging Contextual Cues for Generating Basketball Highlights

The massive growth of sports videos has resulted in a need for automatic generation of sports highlights that are comparable in quality to the hand-edited highlights produced by broadcasters such as ESPN. Unlike previous works that mostly use audio-visual cues derived from the video, we propose an approach that additionally leverages contextual cues derived from the environment that the game is being played in. The contextual cues provide information about the excitement levels in the game, which can be ranked and selected to automatically produce high-quality basketball highlights. We introduce a new dataset of 25 NCAA games along with their play-by-play stats and the ground-truth excitement data for each basket. We explore the informativeness of five different cues derived from the video and from the environment through user studies. Our experiments show that for our study participants, the highlights produced by our system are comparable to the ones produced by ESPN for the same games.

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Paper in IJCARS (2016) on “Automated video-based assessment of surgical skills for training and evaluation in medical schools”

September 2nd, 2016 Irfan Essa Posted in Activity Recognition, Aneeq Zia, Computer Vision, Eric Sarin, Mark Clements, Medical, MICCAI, Thomas Ploetz, Vinay Bettadapura, Yachna Sharma No Comments »

Paper

  • A. Zia, Y. Sharma, V. Bettadapura, E. L. Sarin, T. Ploetz, M. A. Clements, and I. Essa (2016), “Automated video-based assessment of surgical skills for training and evaluation in medical schools,” International Journal of Computer Assisted Radiology and Surgery, vol. 11, iss. 9, pp. 1623-1636, 2016. [WEBSITE] [DOI] [BIBTEX]
    @Article{    2016-Zia-AVASSTEMS,
      author  = {Zia, Aneeq and Sharma, Yachna and Bettadapura,
          Vinay and Sarin, Eric L and Ploetz, Thomas and
          Clements, Mark A and Essa, Irfan},
      doi    = {10.1007/s11548-016-1468-2},
      journal  = {International Journal of Computer Assisted
          Radiology and Surgery},
      month    = {September},
      number  = {9},
      pages    = {1623--1636},
      publisher  = {Springer Berlin Heidelberg},
      title    = {Automated video-based assessment of surgical skills
          for training and evaluation in medical schools},
      url    = {http://link.springer.com/article/10.1007/s11548-016-1468-2},
      volume  = {11},
      year    = {2016}
    }

Abstract

2016-Zia-AVASSTEMS

Sample frames from our video dataset

Purpose: Routine evaluation of basic surgical skills in medical schools requires considerable time and effort from supervising faculty. For each surgical trainee, a supervisor has to observe the trainees in- person. Alternatively, supervisors may use training videos, which reduces some of the logistical overhead. All these approaches, however, are still incredibly time consuming and involve human bias. In this paper, we present an automated system for surgical skills assessment by analyzing video data of surgical activities.

Method : We compare different techniques for video-based surgical skill evaluation. We use techniques that capture the motion information at a coarser granularity using symbols or words, extract motion dynamics using textural patterns in a frame kernel matrix, and analyze fine-grained motion information using frequency analysis. Results: We were successfully able to classify surgeons into different skill levels with high accuracy. Our results indicate that fine-grained analysis of motion dynamics via frequency analysis is most effective in capturing the skill relevant information in surgical videos.

Conclusion: Our evaluations show that frequency features perform better than motion texture features, which in turn perform better than symbol/word-based features. Put succinctly, skill classification accuracy is positively correlated with motion granularity as demonstrated by our results on two challenging video datasets.

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Paper (WACV 2016) “Discovering Picturesque Highlights from Egocentric Vacation Videos”

March 7th, 2016 Irfan Essa Posted in Computational Photography and Video, Computer Vision, Daniel Castro, PAMI/ICCV/CVPR/ECCV, Vinay Bettadapura No Comments »

Paper

  • D. Castro, V. Bettadapura, and I. Essa (2016), “Discovering Picturesque Highlights from Egocentric Vacation Video,” in Proceedings of IEEE Winter Conference on Applications of Computer Vision (WACV), 2016. [PDF] [WEBSITE] [arXiv] [BIBTEX]
    @InProceedings{    2016-Castro-DPHFEVV,
      arxiv    = {http://arxiv.org/abs/1601.04406},
      author  = {Daniel Castro and Vinay Bettadapura and Irfan
          Essa},
      booktitle  = {Proceedings of IEEE Winter Conference on
          Applications of Computer Vision (WACV)},
      month    = {March},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2016-Castro-DPHFEVV.pdf},
      title    = {Discovering Picturesque Highlights from Egocentric
          Vacation Video},
      url    = {http://www.cc.gatech.edu/cpl/projects/egocentrichighlights/},
      year    = {2016}
    }

Abstract

2016-Castro-DPHFEVVWe present an approach for identifying picturesque highlights from large amounts of egocentric video data. Given a set of egocentric videos captured over the course of a vacation, our method analyzes the videos and looks for images that have good picturesque and artistic properties. We introduce novel techniques to automatically determine aesthetic features such as composition, symmetry, and color vibrancy in egocentric videos and rank the video frames based on their photographic qualities to generate highlights. Our approach also uses contextual information such as GPS, when available, to assess the relative importance of each geographic location where the vacation videos were shot. Furthermore, we specifically leverage the properties of egocentric videos to improve our highlight detection. We demonstrate results on a new egocentric vacation dataset which includes 26.5 hours of videos taken over a 14-day vacation that spans many famous tourist destinations and also provide results from a user-study to access our results.

 

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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 Ubicomp 2015: “A Practical Approach for Recognizing Eating Moments with Wrist-Mounted Inertial Sensing”

September 8th, 2015 Irfan Essa Posted in ACM UIST/CHI, Activity Recognition, Behavioral Imaging, Edison Thomaz, Gregory Abowd, Health Systems, Machine Learning, Mobile Computing, Papers, UBICOMP, Ubiquitous Computing No Comments »

Paper

  • E. Thomaz, I. Essa, and G. D. Abowd (2015), “A Practical Approach for Recognizing Eating Moments with Wrist-Mounted Inertial Sensing,” in Proceedings of ACM International Conference on Ubiquitous Computing (UBICOMP), 2015. [PDF] [BIBTEX]
    @InProceedings{    2015-Thomaz-PAREMWWIS,
      author  = {Edison Thomaz and Irfan Essa and Gregory D. Abowd},
      booktitle  = {Proceedings of ACM International Conference on
          Ubiquitous Computing (UBICOMP)},
      month    = {September},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Thomaz-PAREMWWIS.pdf},
      title    = {A Practical Approach for Recognizing Eating Moments
          with Wrist-Mounted Inertial Sensing},
      year    = {2015}
    }

Abstract

Thomaz-UBICOMP15.pngRecognizing when eating activities take place is one of the key challenges in automated food intake monitoring. Despite progress over the years, most proposed approaches have been largely impractical for everyday usage, requiring multiple onbody sensors or specialized devices such as neck collars for swallow detection. In this paper, we describe the implementation and evaluation of an approach for inferring eating moments based on 3-axis accelerometry collected with a popular off-the-shelf smartwatch. Trained with data collected in a semi-controlled laboratory setting with 20 subjects, our system recognized eating moments in two free-living condition studies (7 participants, 1 day; 1 participant, 31 days), with Fscores of 76.1% (66.7% Precision, 88.8% Recall), and 71.3% (65.2% Precision, 78.6% Recall). This work represents a contribution towards the implementation of a practical, automated system for everyday food intake monitoring, with applicability in areas ranging from health research and food journaling.

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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 ACM IUI15: “Inferring Meal Eating Activities in Real World Settings from Ambient Sounds: A Feasibility Study”

April 1st, 2015 Irfan Essa Posted in ACM ICMI/IUI, Activity Recognition, Audio Analysis, Behavioral Imaging, Edison Thomaz, Gregory Abowd, Health Systems, Machine Learning, Multimedia No Comments »

Paper

  • E. Thomaz, C. Zhang, I. Essa, and G. D. Abowd (2015), “Inferring Meal Eating Activities in Real World Settings from Ambient Sounds: A Feasibility Study,” in Proceedings of ACM Conference on Intelligence User Interfaces (IUI), 2015. (Best Short Paper Award) [PDF] [BIBTEX]
    @InProceedings{    2015-Thomaz-IMEARWSFASFS,
      author  = {Edison Thomaz and Cheng Zhang and Irfan Essa and
          Gregory D. Abowd},
      awards  = {(Best Short Paper Award)},
      booktitle  = {Proceedings of ACM Conference on Intelligence User
          Interfaces (IUI)},
      month    = {May},
      pdf    = {http://www.cc.gatech.edu/~irfan/p/2015-Thomaz-IMEARWSFASFS.pdf},
      title    = {Inferring Meal Eating Activities in Real World
          Settings from Ambient Sounds: A Feasibility Study},
      year    = {2015}
    }

Abstract

2015-04-IUI-AwardDietary self-monitoring has been shown to be an effective method for weight-loss, but it remains an onerous task despite recent advances in food journaling systems. Semi-automated food journaling can reduce the effort of logging, but often requires that eating activities be detected automatically. In this work we describe results from a feasibility study conducted in-the-wild where eating activities were inferred from ambient sounds captured with a wrist-mounted device; twenty participants wore the device during one day for an average of 5 hours while performing normal everyday activities. Our system was able to identify meal eating with an F-score of 79.8% in a person-dependent evaluation, and with 86.6% accuracy in a person-independent evaluation. Our approach is intended to be practical, leveraging off-the-shelf devices with audio sensing capabilities in contrast to systems for automated dietary assessment based on specialized sensors.

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Paper in WACV (2015): “Semantic Instance Labeling Leveraging Hierarchical Segmentation”

January 6th, 2015 Irfan Essa Posted in Computer Vision, Henrik Christensen, PAMI/ICCV/CVPR/ECCV, Papers, Robotics, Steven Hickson No Comments »

Paper

  • 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}
    }

Abstract

Most of the approaches for indoor RGBD semantic labeling focus on using pixels or superpixels to train a classifier. In this paper, we implement a higher level segmentation using a hierarchy of superpixels to obtain a better segmentation for training our classifier. By focusing on meaningful segments that conform more directly to objects, regardless of size, we train a random forest of decision trees as a classifier using simple features such as the 3D size, LAB color histogram, width, height, and shape as specified by a histogram of surface normals. We test our method on the NYU V2 depth dataset, a challenging dataset of cluttered indoor environments. Our experiments using the NYU V2 depth dataset show that our method achieves state of the art results on both a general semantic labeling introduced by the dataset (floor, structure, furniture, and objects) and a more object specific semantic labeling. We show that training a classifier on a segmentation from a hierarchy of super pixels yields better results than training directly on super pixels, patches, or pixels as in previous work.2015-Hickson-SILLHS_pdf

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Paper in IEEE WACV (2015): “Finding Temporally Consistent Occlusion Boundaries using Scene Layout”

January 6th, 2015 Irfan Essa Posted in Computational Photography and Video, Computer Vision, Matthias Grundmann, PAMI/ICCV/CVPR/ECCV, Papers, S. Hussain Raza, Uncategorized No Comments »

Paper

  • 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}
    }

Abstract

We present an algorithm for finding temporally consistent occlusion boundaries in videos to support segmentation of dynamic scenes. We learn occlusion boundaries in a pairwise Markov random field (MRF) framework. We first estimate the probability of a spatiotemporal edge being an occlusion boundary by using appearance, flow, and geometric features. Next, we enforce occlusion boundary continuity in an MRF model by learning pairwise occlusion probabilities using a random forest. Then, we temporally smooth boundaries to remove temporal inconsistencies in occlusion boundary estimation. Our proposed framework provides an efficient approach for finding temporally consistent occlusion boundaries in video by utilizing causality, redundancy in videos, and semantic layout of the scene. We have developed a dataset with fully annotated ground-truth occlusion boundaries of over 30 videos (∼5000 frames). This dataset is used to evaluate temporal occlusion boundaries and provides a much-needed baseline for future studies. We perform experiments to demonstrate the role of scene layout, and temporal information for occlusion reasoning in video of dynamic scenes.

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