Peer-reviewed publication
Indian Sign Language Recognition
Attention-based LSTM for recognising ISL gestures from video. Published at IEEE InC4 2025.
- Role
- Co-author — third of four authors
- Domain
- Machine Learning & Data Science
- Stack
- Python · TensorFlow · NumPy · pandas · OpenCV
- Result
- 94% classification accuracy
Overview
An attention-based LSTM that recognises Indian Sign Language gestures from video, published at IEEE InC4 2025. The model learns which frames of a gesture matter, rather than treating every frame alike.
The question
Indian Sign Language is used by millions and supported by far less technology than American Sign Language. And a sign is a movement, not a pose — models that classify frames one at a time miss what makes a gesture mean what it means.
Not every frame of a sign matters equally. Attention lets the model weight the ones that do.
Method
Record
A new dataset: seven ISL terms, filmed at high resolution — no gloves or depth sensors.
Extract
Pose and hand keypoints taken from every frame, low-value points dropped to cut noise.
Sequence
Each clip becomes a fixed-length sequence of keypoint frames.
Model
Three stacked LSTM layers learn short- and long-range movement.
Attend
An attention layer weights frames by importance before dense layers and a softmax classify the sign.
Evaluation
- Metrics
- Accuracy, precision, recall and F1, averaged over k-fold cross-validation.
- Baselines
- Two stacked GRUs, a GRU-LSTM hybrid, and VGG19.
- Outcome
- The attention model led all three baselines on every metric. Full figures are in the paper.
My Role
Role
Co-author — third of four authors
Contribution
- Contributed to the attention-based LSTM model for gesture classification
- Worked on frame-weighting so the model focuses on the most informative frames of a sequence
- Contributed to the empirical evaluation against a traditional LSTM baseline
Team Context
Third author on a four-author paper with faculty supervision at Bennett University.
Results
94%
classification accuracy
210
video samples, 7 ISL terms
Limits
Seven signs, a few hundred clips, and a small group of young signers recorded in controlled conditions. It recognises isolated signs, not continuous signing, and was not evaluated on signers held out from training — so the accuracy says how well it separates these seven gestures, not how it would do on a stranger. The paper itself names lighting, background and signer variation as future work.
What I'd Improve
- Evaluate signer-independently — train on some people, test on others. First fix, and the one that would most change the headline number.
- Add facial expression and body posture, which carry grammatical meaning in ISL and are ignored here.
- Grow the vocabulary and move from isolated signs toward continuous sentences.