Hunter Heidenreich | ML Research Scientist — Page 23

Optical Chemical Structure Recognition

OSRA at CLEF-IP 2012: Native TIFF Processing for Patents

Benchmarks OSRA on CLEF-IP 2012 patent data, showing native image processing improves precision from 0.433 to 0.708 over external splitting tools. Describes OSRA’s pairwise distance algorithm for segmentation that handles overlapping molecules better than bounding boxes.

Optical Chemical Structure Recognition

Overview of the TREC 2011 Chemical IR Track Benchmark

This resource paper details the third TREC Chemical IR campaign, introducing a novel Image-to-Structure task and analyzing 36 runs from 9 groups to benchmark chemical information retrieval.

Optical Chemical Structure Recognition

Probabilistic OCSR with Markov Logic Networks

This paper introduces MLOCSR, a system that pipelines low-level image vectorization with a high-level probabilistic Markov Logic Network to recognize chemical structures. It replaces brittle heuristics with weighted logic rules, significantly outperforming state-of-the-art systems like OSRA on degraded or low-resolution images.

Optical Chemical Structure Recognition
Optical Chemical Structure Recognition workflow visualization

Research on Chemical Expression Images Recognition

Proposes a new OCSR workflow that improves recognition rates by separating adhesive chemical symbols and specifically handling virtual/real wedge bonds using vectorization, achieving 90% exact match vs 82.2% for OSRA baseline.

Optical Chemical Structure Recognition

Chemical Structure Recognition (Rule-Based)

This paper introduces MolRec, a rule-based system for Optical Chemical Structure Recognition (OCSR). It defines a set of 18 geometric rewrite rules to disambiguate bonds and atoms in vectorised diagram images, demonstrating higher accuracy than the contemporary state-of-the-art (OSRA).

Optical Chemical Structure Recognition
Diagram of the ChemInk sketch recognition system converting freehand chemical drawings into structured molecular data

ChemInk: Real-Time Recognition for Chemical Drawings

ChemInk introduces a sketch recognition system for chemical diagrams that combines multi-level visual features via a joint Conditional Random Field (CRF), achieving 97.4% accuracy and outperforming CAD tools in user speed.

Optical Chemical Structure Recognition
Diagram of the CLiDE Pro system for segmenting document images and reconstructing chemical connection tables

CLiDE Pro: Optical Chemical Structure Recognition Tool

This paper introduces CLiDE Pro, an advanced OCSR system that segments document images and reconstructs chemical connection tables. It features novel handling for crossing bonds and generic structures, validating performance on a publicly released benchmark of 454 scanned images.

Optical Chemical Structure Recognition

Imago: Open-Source Chemical Structure Recognition (2011)

Imago is an open-source, cross-platform C++ toolkit designed to recognize 2D chemical structure images from scientific papers and convert them into machine-readable molecule formats using a rule-based pipeline.

Optical Chemical Structure Recognition

Kekulé-1 System for Chemical Structure Recognition

This paper introduces Kekulé-1, one of the first successful Optical Chemical Structure Recognition (OCSR) systems. It details a hybrid approach using neural networks for character recognition and heuristic vectorization for bond detection, achieving 98.9% accuracy on a test set of 524 structures.

Optical Chemical Structure Recognition

OSRA at TREC-CHEM 2011: Optical Structure Recognition

This paper details the algorithmic pipeline of OSRA, an open-source tool that converts raster images of chemical diagrams into connection tables (SMILES/SDF). It outlines specific heuristics for page segmentation, vectorization, and atom recognition used in the TREC-CHEM Image2Structure task.

Optical Chemical Structure Recognition

Structural Analysis of Handwritten Chemical Formulas

This paper proposes a strategy for interpreting handwritten chemical formulas by converting bitmap images into a dynamic structural graph of quadrilaterals. It achieves ~97% recognition on graphical elements by using recursive ‘specialists’ to identify chemical bonds and rings.

Computational Social Science
NOMINATE spatial plot showing Senate vote on Balanced Budget Amendment (1995) with legislators positioned on liberal-conservative dimension

A Spatial Model for Legislative Roll Call Analysis

This paper introduces NOMINATE, a probabilistic spatial model that recovers metric coordinates for legislators and roll calls from nominal voting data, demonstrating that a single liberal-conservative dimension explains the vast majority of Congressional voting behavior.