Blog
The latest news from Google AI
Announcing AVA: A Finely Labeled Video Dataset for Human Action Understanding
Thursday, October 19, 2017
Posted by Chunhui Gu & David Ross, Software Engineers
Teaching machines to understand human actions in videos is a fundamental research problem in Computer Vision, essential to applications such as personal video search and discovery, sports analysis, and gesture interfaces. Despite exciting breakthroughs made over the past years in
classifying
and
finding objects
in images, recognizing human actions still remains a big challenge. This is due to the fact that actions are, by nature, less well-defined than objects in videos, making it difficult to construct a finely labeled action video dataset. And while many benchmarking datasets, e.g.,
UCF101
,
ActivityNet
and DeepMind’s
Kinetics
, adopt the labeling scheme of image classification and assign one label to each video or video clip in the dataset, no dataset exists for complex scenes containing multiple people who could be performing different actions.
In order to facilitate further research into human action recognition, we have released AVA, coined from “atomic visual actions”, a new dataset that provides multiple action labels for each person in extended video sequences. AVA consists of URLs for publicly available videos from YouTube, annotated with a set of 80 atomic actions (e.g. “walk”, “kick (an object)”, “shake hands”) that are spatial-temporally localized, resulting in 57.6k video segments, 96k labeled humans performing actions, and a total of 210k action labels. You can browse the
website
to explore the dataset and download annotations, and read our
arXiv paper
that describes the design and development of the dataset.
Compared with other action datasets, AVA possesses the following key characteristics:
Person-centric annotation.
Each action label is associated with a person rather than a video or clip. Hence, we are able to assign different labels to multiple people performing different actions in the same scene, which is quite common.
Atomic visual actions.
We limit our action labels to fine temporal scales (3 seconds), where actions are physical in nature and have clear visual signatures.
Realistic video material.
We use movies as the source of AVA, drawing from a variety of genres and countries of origin. As a result, a wide range of human behaviors appear in the data.
Examples of 3-second video segments (from
Video Source
) with their bounding box annotations in the middle frame of each segment. (For clarity, only one bounding box is shown for each example.)
To create AVA, we first collected a diverse set of long form content from YouTube, focusing on the “film” and “television” categories, featuring professional actors of many different nationalities. We analyzed a 15 minute clip from each video, and uniformly partitioned it into 300 non-overlapping 3-second segments. The sampling strategy preserved sequences of actions in a coherent temporal context.
Next, we manually labeled all bounding boxes of persons in the middle frame of each 3-second segment. For each person in the bounding box, annotators selected a variable number of labels from a pre-defined atomic action vocabulary (with 80 classes) that describe the person’s actions within the segment. These actions were divided into three groups: pose/movement actions, person-object interactions, and person-person interactions. Because we exhaustively labeled all people performing all actions, the frequencies of AVA’s labels followed a long-tail distribution, as summarized below.
Distribution of AVA’s atomic action labels. Labels displayed in the x-axis are only a partial set of our vocabulary.
The unique design of AVA allows us to derive some interesting statistics that are not available in other existing datasets. For example, given the large number of persons with at least two labels, we can measure the co-occurrence patterns of action labels. The figure below shows the top co-occurring action pairs in AVA with their co-occurrence scores. We confirm expected patterns such as people frequently play instruments while singing, lift a person while playing with kids, and hug while kissing.
Top co-occurring action pairs in AVA.
To evaluate the effectiveness of human action recognition systems on the AVA dataset, we implemented an existing baseline deep learning model that obtains highly competitive performance on the much smaller
JHMDB dataset
. Due to challenging variations in zoom, background clutter, cinematography, and appearance variation, this model achieves a relatively modest performance when correctly identifying actions on AVA (18.4%
mAP
). This suggests that AVA will be a useful testbed for developing and evaluating new action recognition architectures and algorithms for years to come.
We hope that the release of AVA will help improve the development of human action recognition systems, and provide opportunities to model complex activities based on labels with fine spatio-temporal granularity at the level of individual person’s actions. We will continue to expand and improve AVA, and are eager to hear feedback from the community to help us guide future directions. Please join the AVA users
mailing list
to receive dataset updates as well as to send us emails for feedback.
Acknowledgements
The core team behind AVA includes Chunhui Gu, Chen Sun, David Ross, Caroline Pantofaru, Yeqing Li, Sudheendra Vijayanarasimhan, George Toderici, Susanna Ricco, Rahul Sukthankar, Cordelia Schmid, and Jitendra Malik. We thank many Google colleagues and annotators for their dedicated support on this project.
Labels
2018
accessibility
ACL
ACM
Acoustic Modeling
Adaptive Data Analysis
ads
adsense
adwords
Africa
AI
Algorithms
Android
Android Wear
API
App Engine
App Inventor
April Fools
Art
Audio
Augmented Reality
Australia
Automatic Speech Recognition
AutoML
Awards
BigQuery
Cantonese
Chemistry
China
Chrome
Cloud Computing
Collaboration
Compression
Computational Imaging
Computational Photography
Computer Science
Computer Vision
conference
conferences
Conservation
correlate
Course Builder
crowd-sourcing
CVPR
Data Center
Data Discovery
data science
datasets
Deep Learning
DeepDream
DeepMind
distributed systems
Diversity
Earth Engine
economics
Education
Electronic Commerce and Algorithms
electronics
EMEA
EMNLP
Encryption
entities
Entity Salience
Environment
Europe
Exacycle
Expander
Faculty Institute
Faculty Summit
Flu Trends
Fusion Tables
gamification
Gboard
Gmail
Google Accelerated Science
Google Books
Google Brain
Google Cloud Platform
Google Docs
Google Drive
Google Genomics
Google Maps
Google Photos
Google Play Apps
Google Science Fair
Google Sheets
Google Translate
Google Trips
Google Voice Search
Google+
Government
grants
Graph
Graph Mining
Hardware
HCI
Health
High Dynamic Range Imaging
ICCV
ICLR
ICML
ICSE
Image Annotation
Image Classification
Image Processing
Inbox
India
Information Retrieval
internationalization
Internet of Things
Interspeech
IPython
Journalism
jsm
jsm2011
K-12
Kaggle
KDD
Keyboard Input
Klingon
Korean
Labs
Linear Optimization
localization
Low-Light Photography
Machine Hearing
Machine Intelligence
Machine Learning
Machine Perception
Machine Translation
Magenta
MapReduce
market algorithms
Market Research
Mixed Reality
ML
ML Fairness
MOOC
Moore's Law
Multimodal Learning
NAACL
Natural Language Processing
Natural Language Understanding
Network Management
Networks
Neural Networks
NeurIPS
Nexus
Ngram
NIPS
NLP
On-device Learning
open source
operating systems
Optical Character Recognition
optimization
osdi
osdi10
patents
Peer Review
ph.d. fellowship
PhD Fellowship
PhotoScan
Physics
PiLab
Pixel
Policy
Professional Development
Proposals
Public Data Explorer
publication
Publications
Quantum AI
Quantum Computing
Reinforcement Learning
renewable energy
Research
Research Awards
resource optimization
Robotics
schema.org
Search
search ads
Security and Privacy
Semantic Models
Semi-supervised Learning
SIGCOMM
SIGMOD
Site Reliability Engineering
Social Networks
Software
Sound Search
Speech
Speech Recognition
statistics
Structured Data
Style Transfer
Supervised Learning
Systems
TensorBoard
TensorFlow
TPU
Translate
trends
TTS
TV
UI
University Relations
UNIX
Unsupervised Learning
User Experience
video
Video Analysis
Virtual Reality
Vision Research
Visiting Faculty
Visualization
VLDB
Voice Search
Wiki
wikipedia
WWW
Year in Review
YouTube
Archive
2019
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2018
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2017
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2016
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2015
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2014
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2013
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2012
Dec
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2011
Dec
Nov
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2010
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2009
Dec
Nov
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2008
Dec
Nov
Oct
Sep
Jul
May
Apr
Mar
Feb
2007
Oct
Sep
Aug
Jul
Jun
Feb
2006
Dec
Nov
Sep
Aug
Jul
Jun
Apr
Mar
Feb
Feed
Follow @googleai
Give us feedback in our
Product Forums
.
