arXiv Computer Vision

Handwriting Trajectory Recovery via Autoregressive Ordered Stroke Instance Prediction

The paper presents a two‑stage method for recovering handwriting trajectories from static images. First, it predicts ordered stroke instances autoregressively, then reconstructs continuous motion within each stroke using direction‑related cues. Experiments on Chinese, English, and Tamil handwriting show that this ordered prediction outperforms post‑hoc ordering and baseline models, and that sampling density significantly impacts performance.

arXiv AI
6d ago

Segment-Level Risk Discovery in Online Handwriting for Alzheimer's Disease Detection

The paper introduces NormPaST‑Risk, a novel framework that detects Alzheimer’s disease from online handwriting by focusing on local, segment‑level risk rather than whole‑trajectory features. It employs a multi‑scale temporal encoder, a Paper‑Air state‑space model to separate on‑paper motor execution from in‑air planning, and a healthy‑normative branch to learn normal handwriting dynamics. A weakly supervised segment‑risk module identifies high‑risk handwriting segments, achieving superior AD/HC classification on the DARWIN benchmark and offering interpretable evidence linked to disease‑related handwriting changes.

By Changqing Gong, Huafeng Qin, Moun\^im A. El-Yacoubi
arXiv Machine Learning
Sep 10

Rotation-free Online Handwritten Character Recognition Using Linear Recurrent Units

The paper presents a rotation‑free online handwritten character recognition system that uses Sliding Window Path Signature (SW‑PS) to extract local structural features and a lightweight Linear Recurrent Unit (LRU) classifier. The LRU blends the incremental processing of RNNs with the parallel training efficiency of state‑space models to model dynamic stroke characteristics. Experiments on rotated CASIA‑OLHWDB1.1 subsets (digits, English upper letters, Chinese radicals) achieved accuracies of 99.62%, 96.67%, and 94.33% respectively, outperforming competing models in convergence speed and test accuracy.

By Zhe Ling, Sicheng Yu, Danyu Yang
arXiv Machine Learning
Sep 14

Write on Paper and Get the Online Digital Trace:\newline A New Era for Handwriting

The paper introduces a new method for capturing the digital trace of handwriting written on regular paper. It combines a sensor-equipped digital pen with advanced AI algorithms to reconstruct the pen’s trajectory in real time, eliminating the need for specialized styluses or substrates. The approach integrates hardware development and embedded AI software to enable seamless digitization of traditional handwriting.

By Florent Imbert, Yann Soullard, Eric Anquetil, Tanja Harbaum, Alexey Serdyuk, Fabian Kress, Tim Hamann, Peter Kampf