Engineering

ML Tool for Hand Landmark Detection

Developed an automated machine learning pipeline to replace the UF Musculoskeletal Biomechanics Lab’s slow, manual ImageJ processing of hand images, enabling rapid, consistent extraction of 31 standardized hand-landmark measurements from an original dataset of 495 hand images.

My Role

Independent Researcher & ML Developer

Duration

1 yr 8 months

Tools

Python, TensorFlow/Keras, MobileNetV2 architecture

Overview

Challenge

Challenge

Challenge

The 1987–1988 Anthropometric Survey of U.S. Army Personnel used outdated, limited‐demographic hand measurements, and the lab’s reliance on manual ImageJ workflows was time-consuming and prone to human error, hindering large-scale, inclusive biomechanical studies.

Solution

Solution

Solution

I adapted a facial landmark detection model (MobileNetV2 architecture) for hand landmark detection by building a dataset of manually annotated hand images, preprocessing each with orientation correction and color thresholding, and fine-tuning the network’s width multiplier (α) to maximize landmark localization accuracy.

Research

  • Conducted an in-depth literature review on MobileNetV2’s architecture and transfer learning best practices, consulting published papers and ML experts to identify which hyperparameters (like the width multiplier α) to experiment with.

  • Mapped the original U.S. Army Personnel survey landmark numbering to our annotation scheme by creating a detailed key that aligned each measurement description to its corresponding image landmark, ensuring accurate distance calculations in downstream computation and error analysis.

Optimal Hyperparameter (α=1.00)

The model with α=1.00 balanced performance and complexity, yielding the clearest landmark alignment against ground truth compared to α=0.35, α=0.75, and other values tested.

Optimal Hyperparameter (α=1.00)

The model with α=1.00 balanced performance and complexity, yielding the clearest landmark alignment against ground truth compared to α=0.35, α=0.75, and other values tested.

Optimal Hyperparameter (α=1.00)

The model with α=1.00 balanced performance and complexity, yielding the clearest landmark alignment against ground truth compared to α=0.35, α=0.75, and other values tested.

Dataset Diversity Constraints

Dataset Diversity Constraints

Dataset Diversity Constraints

Accuracy Benchmark

Accuracy Benchmark

Accuracy Benchmark

Design

Organized the 495 annotated images into four orientation folders based on ruler position (bottom/top/left/right), applied an OpenCV‐based pipeline for color-threshold detection and rotation rules, excluded top-oriented images (final dataset included 408 images), removed ruler landmarks, and split data 70/15/15. All preprocessing and initial training occurred in Jupyter Notebook; subsequent runs used Colab’s T4 GPU. Models trained for 30 epochs (batch size 4) with MSE loss and Adam optimizer, saving the best checkpoint via early stopping.

Results

  • Reduced per-image landmark extraction time from minutes to milliseconds.

  • Demonstrated 79.55% average detection accuracy, validating AI-driven anthropometry.

  • Established a scalable framework for expanding dataset diversity and further model refinement.