Unsupervised Audio-Visual Lecture Segmentation

Darshan Singh S*, Anchit Gupta*, C.V. Jawahar and Makarand Tapaswi

CVIT,   IIIT Hyderabad

WACV, 2023

[ Code ]   | [Dataset ] | [ arXiv ] | [ Demo Video ]

 We address the task of lecture segmentation in an unsupervised manner. We show an example of a lecture segmented using our method. Our method predicts segments close to the ground-truth. Note that our method does not predict the segment labels, they are only shown so that the reader can appreciate the different topics.

Abstract

Paper

• 

  Unsupervised Audio-Visual Lecture Segmentation

  Darshan Singh S, Anchit Gupta, C.V. Jawahar and Makarand Tapaswi
  Unsupervised Audio-Visual Lecture Segmentation, WACV, 2023.
  [PDF ] | [BibTeX]

  Updated Soon

Demo

--- COMING SOON ---

Contact

1. Darshan Singh S - This email address is being protected from spambots. You need JavaScript enabled to view it.
2. Anchit Gupta - This email address is being protected from spambots. You need JavaScript enabled to view it.

PSUMNet: Unified Modality Part Streams are All You Need for Efficient Pose-based Action Recognition

Pose-based action recognition is predominantly tackled by approaches which treat the input skeleton in a monolithic fashion, i.e. joints in the pose tree are processed as a whole. However, such approaches ignore the fact that action categories are often characterized by localized action dynamics involving only small subsets of part joint groups involving hands (e.g. ‘Thumbs up’) or legs (e.g. ‘Kicking’). Although part-grouping based approaches exist, each part group is not considered within the global pose frame, causing such methods to fall short. Further, conventional approaches employ independent modality streams (e.g. joint, bone, joint velocity, bone velocity) and train their network multiple times on these streams, which massively increases the number of training parameters

The plot on left shows accuracy against # parameters for our proposed architecture PSUMNet (⋆) and existing approaches for the large-scale NTURGB+D 120 human actions dataset (cross subject).

Comparison between conventional training procedure used in most of the previous approaches (left) and our approach (right).

    To address these issues, we introduce PSUMNet, a novel approach for scalable and efficient pose-based action recognition. At the representation level, we propose a global frame based part stream approach as opposed to conventional modality based streams. Within each part stream, the associated data from multiple modalities is unified and consumed by the processing pipeline. Experimentally, PSUMNet achieves state of the art performance on the widely used NTURGB+D 60/120 dataset and dense joint skeleton dataset NTU 60-X/120-X. PSUMNet is highly efficient and outperforms competing methods which use 100%-400% more parameters. PSUMNet also generalizes to the SHREC hand gesture dataset with competitive performance. Overall, PSUMNet’s scalability, performance and efficiency makes it an attractive choice for action recognition and for deployment on computerestricted embedded and edge devices.

Supplementary          PDF     GitHub

1. Overall Architecture of one stream of the proposed architecture. The input skeleton is passed through Multi modality data generator (MMDG), which generates joint, bone, joint velocity and bone velocity data from input and concatenates each modality data into channel dimension as shown in (b).
2. This multi-modal data is processed via Spatio Temporal Relational Module (STRM) followed by global average pooling and FC.
3. Spatio Temporal Relational Block (STRB), where input data is passed through Spatial Attention Map Generator (SAMG) for spatial relation modeling, followed by Temporal Relational Module. As shown in (a) multiple STRB stacked together make the STRM.
4. Spatial Attention Map Generator (SAMG), dynamically models adjacency matrix (Ahyb)to model spatial relations between joints. Predefined adjacency matrix (A) is used for regularization.
5. Temporal Relational Module (TRM) consists of multiple temporal convolution blocks in parallel. Output of each temporal convolution block is concatenated to generate final features.

DrawMon: A Distributed System for Detection of Atypical Sketch Content in Concurrent Pictionary Games

Nikhil Bansal        Kartik Gupta        Kiruthika Kannan        Sivani Pentapati        Ravi Kiran Sarvadevabhatla       

ACMMM 202

PAPER        DATASET     CODE

What is atypical sketch content and why do we need to detect them?

AtyPict- the first ever dataset of atypical whiteboard content

The categories of atypical content usually encountered in Pictionary sessions are:

• Text: Drawer directly writes the target word or hints related to the target word on the canvas.
• Numerical: Drawer writes numbers on canvas.
• Circles: Drawers often circle a portion of the canvas to emphasize relevant or important content.
• Iconic: Other items used for emphasizing content and abstract compositional structures include drawing a question mark, arrow and other miscellaneous structures (e.g. double-headed arrow, tick marks, addition symbol, cross) and striking out the sketch (which usually implies negation of thesketched item).

Examples of atypical content detection. False negatives are shown as dashed rectangles and false positives as dotted rectangles. Color codes are: text, numbers, question marks, arrows, circles and other icons (e.g. tick marks, addition symbol).

Screenshots of our data collection tool showing Drawer (left) and Guesser (right) activity during a Pictionary game. In this case, the Drawer has violated the game rules by writing text (`Spiderm') on the canvas. An automatic alert notifying the player (see top left of screenshot) and identifying the text location (red box on canvas) is generated by our system DrawMon.

CanvasDash: an intuitive dashboard UI for annotation and visualization

An illustration of annotation using our Canvas-Dash interface.

The distribution of atypical content categories show significant imbalance with category 'Individual letters' occurring more often than others.

DrawMon: a distributed system for sketchcontent-based alert generation

DrawMon - a distributed alert generation system (see figure below). Each game session is managed by a central Session Manager which assigns a unique session id.

• For a given session, whenever a sketch stroke is drawn, the accumulated canvas content (i.e. strokes rendered so far) is tagged with session id and relayed to a shared Session Canvas Queue.
• For efficiency, the canvas content is represented as a lightweight Scalable Vector Graphic (SVG) object. The contents of the Session Canvas Queue are dequeued and rendered into corresponding 512×512 binary images by Distributed Rendering Module in a distributed and parallel fashion.
• The rendered binary images tagged with session id are placed in the Rendered Image Queue. The contents of Rendered Image Queue are dequeued and processed by Distributed Detection Module. Each Detection module consists of our custom-designed deep neural network CanvasNet.

CanvasNet: a model for detecting atypical sketch instances

CanvasNet processes the rendered image as input and outputs a list of atypical activities (if any) along with associated meta-information (atypical content category, 2-D spatial location).

DrawMon in Action

Paper

• PDF: Paper
• arXiv: Coming soon!
• ACMMM-2022: Coming soon!

Code

The code for this work is available on GitHub!
Link: pictionary-cvit/drawmon

Acknowledgements

We wish to acknowledge grant from KCIS - TCS foundation.

Bibtex

Please consider citing the following works if you make use of our work:

@InProceedings{DrawMonACMMM2022,
author="Bansal, Nikhil
and Gupta, Kartik
and Kannan, Kiruthika
and Pentapati, Sivani
and Sarvadevabhatla, Ravi Kiran",
title="DrawMon: A Distributed System for Detection of Atypical Sketch Content in Concurrent Pictionary Games",
booktitle = "ACM conference on Multimedia (ACMMM)",
year="2022"
}

Compressing Video Calls using Synthetic Talking Heads

Madhav Agarwal, Anchit Gupta , Rudrabha Mukhopadhyay, Vinay Namboodiri and C.V. Jawahar

IIIT Hyderabad       Univ. of Bath

BMVC, 2022

[ Interactive Demo ] | [ Demo Video ]

We depict the entire pipeline used for compressing talking head videos. In our pipeline, we detect and send key points of alternate frames over the network and regenerate the talking heads at the receiver’s end. We then use frame interpolation to generate the rest of the frames and use super-resolution to generate high-resolution outputs

Abstract

Paper

• 

  Compressing Video Calls using Synthetic Talking Heads

  Madhav Agarwal, Anchit Gupta, Rudrabha Mukhopadhyay, Vinay Namboodiri and C.V. Jawahar
  The 33rd British Machine Vision Conference, BMVC, 2022.
  [PDF ] | [BibTeX]

  @inproceedings{compressing2022bmvc,
  title={Compressing Video Calls using Synthetic Talking Heads},
  author={Agarwal, Madhav and Gupta, Anchit and Mukhopadhyay, Rudrabha and Namboodiri, Vinay P and Jawahar, CV},
  booktitle={British Machine Vision Conference (BMVC)},
  year={2022} }

Demo

Contact

• Madhav Agarwal - This email address is being protected from spambots. You need JavaScript enabled to view it.
• Rudrabha Mukhopadhyay - This email address is being protected from spambots. You need JavaScript enabled to view it.