arXiv Computer Vision

uTHCD-C: A Corruption-Robustness Benchmark for Tamil Handwritten Character Recognition

The paper introduces uTHCD-C, a benchmark for assessing corruption robustness in Tamil handwritten character recognition (HCR). It defines ten corruption types—including a stroke‑thinning corruption—across five severity levels and evaluates nine convolutional and transformer models using cross‑validation and writer‑independent testing. The study reports mean Corruption Error (mCE) scores, showing ConvNeXt and Swin as most robust, while also comparing computational efficiency metrics.

arXiv Computer Vision
Oct 28

Frugal Handwritten Text Recognition for Sub-Saharan Civil-Status Registers: A Smartphone-to-Records Pipeline with CPU-Only Inference

The paper presents a low‑resource pipeline for converting handwritten civil‑status registers in Sub‑Saharan Africa into searchable text using only a smartphone for capture and a laptop CPU for inference. It introduces a new corpus of 1,568 smartphone images from a Chadian municipal registry, and shows that a classical preprocessing stage plus a fine‑tuned Kraken recognizer can achieve a character error rate of 0.50% and a word error rate of 3.37% on a test set with writers seen during training. The recognizer is lightweight (61 MiB) and runs in under 6 s per image on a six‑core laptop, demonstrating that such a frugal system is feasible for local administrations lacking GPUs or reliable connectivity.

By Ousmane Hamadou, Jean Louis Kedieng Ebongue Fendji
arXiv Machine Learning
Oct 19

Handwritten Text Recognition Lives in the High-Pixel Variance Subspace

The paper investigates self‑supervised pretraining for Handwritten Text Recognition (HTR) and finds that pixel‑reconstruction methods outperform contrastive methods, a contrast to natural‑image classification. The authors argue that discriminative information for HTR is concentrated in high‑variance pixel directions, and they test six SSL methods across six handwriting benchmarks in five languages, showing that pixel‑grounded approaches achieve the lowest character error rates and are more label‑efficient. When combined with a pretrained LLM decoder, a frozen pixel‑grounded encoder rivals fully fine‑tuned supervised baselines, underscoring the importance of aligning representations with high‑variance pixel subspaces.

By Carlos Garrido-Munoz, Jorge Calvo-Zaragoza
arXiv AI
Aug 20

OmniHandwritingOCR: A Diagnostic Benchmark for Evaluating Multimodal LLMs in Handwritten OCR Scenarios

OmniHandwritingOCR is a diagnostic benchmark designed to evaluate multimodal large language models (MLLMs) and OCR systems on handwritten text and mathematical expression recognition. It comprises 77.57K labeled images across six subtasks and twelve subsets, including a difficulty‑stratified multi‑line formula corpus that tests robustness to increasing structural complexity. The benchmark reveals that current systems perform poorly on complex multi‑line formulas, exhibit variable rankings across languages and formula settings, and sometimes hallucinate corrections that are not visually supported.

By Zinuo Guo, Min Zhang, Bo Jiang
arXiv Machine Learning
Jun 25

Learning Diachronic Representations of Ancient Greek Letterforms

arXiv:2606. 24984v1 Announce Type: new Abstract: Learning representations that remain robust across centuries of variation in handwriting is a key challenge in diachronic representation learning.

By John Pavlopoulos, Spyros Barbakos, Lavinia Ferretti, Dionysis Voulgarakis, Asimina Paparrigopoulou, Maria Konstantinidou, Giuseppe De Gregorio, Isabelle Marthot-Santaniello, Paraskevi Platanou, Holger Essler
arXiv Computer Vision
Sep 28

A Multi-Stage Framework for Kuzushiji Character Recognition in Japanese Historical Documents

The paper presents a multi‑stage framework for recognizing Kuzushiji characters in Japanese historical documents. It combines character detection, cropping, classification, reading‑order reconstruction via adaptive column clustering, and large‑language‑model‑based post‑OCR correction. The authors also augment data synthetically, correct dataset annotations, and introduce new test sets, achieving significant character error rate reductions on real, synthetic, and out‑of‑domain data.

By Rui-Yang Ju, Kohei Yamashita, Hirotaka Kameko, Shinsuke Mori
arXiv Computer Vision
Sep 30

Hybrid Feature Learning for Handwriting Verification

The paper introduces a Hybrid Deep Learning (HDL) architecture that combines Auto-Learned Features (ALF) and Human-Engineered Features (HEF) for handwriting verification. ALF is extracted using a Two Channel Convolutional Neural Network (TC-CNN) or a Two Channel Autoencoder (TC-AE), while HEF is obtained via Gradient Structural Concavity (GSC) or Scale Invariant Feature Transform (SIFT). Experiments on 150,000 pairs of the word "AND" from 1,500 writers show that the HDL model using AE-GSC achieves 99.7% accuracy on a seen writer dataset and 92.16% on a shuffled writer dataset, outperforming CEDAR-FOX, and AE-SIFT performs comparably on unseen writers.

By Seyed Mohammad Abuzar Hashemi, Mihir Chauhan, Jun Chu, Sargur Srihari
arXiv AI
Sep 4

How Far Can Synthetic Data Take Thai OCR?

The paper explores how synthetic data can be used to train a Thai OCR model without real OCR labels. By systematically varying factors such as typeface diversity, page structure, and handwriting glyphs, the authors identify which aspects of realism most improve transfer to real documents. Using these insights, they adapt a large PaddleOCR model into Wayu‑Paxa‑OCR‑Zero, achieving a median character error rate of 1.24% on printed pages and 20.55% on handwriting, outperforming existing Thai OCR systems.

By Kunat Pipatanakul