Probabilistic Graphical Model for Form-Based Information Classification

Solution Overview

Problem

Current techniques for extracting and classifying information from form-based documents or images are often heuristic-based and assume independent features, lacking a trainable, adaptable, and reliable model for information extraction and classification.

Innovation Solution

A method and system utilizing a probabilistic graphical model trained with token features and contextual features extracted from a training corpus, which includes a token extractor, feature generator, and classifier to classify actual tokens from data using a linear-chain conditional random field model.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If heuristic-based classification techniques are used, then implementation simplicity is maintained, but classification precision and reliability deteriorate

Engineering Contradiction:
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces heuristic-based mechanical classification rules with a probabilistic graphical model (conditional random field) that uses probability theory and graphical representations to model relationships between tokens and their classes. This substitution enables the system to learn from training data and capture contextual dependencies, significantly improving classification precision while maintaining a structured approach to complexity through the graphical model framework.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If feature independence assumption is made, then computational complexity is reduced, but classification accuracy deteriorates due to inability to capture contextual relationships

Engineering Contradiction:
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces contextual features as intermediaries that capture relationships between tokens and their surrounding environment. These contextual features act as mediators that encode dependency information (such as positional relationships, neighboring token characteristics, and structural context) without requiring direct modeling of all pairwise feature interactions. This approach maintains computational tractability while significantly improving classification accuracy by incorporating contextual information.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the feature representation into token-level features and contextual features. This segmentation allows the model to independently process local token characteristics while separately capturing global contextual relationships through the conditional random field structure. The segmentation strategy enables the system to model feature relationships in a modular fashion, improving accuracy without overwhelming computational complexity.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If trainable models are implemented, then adaptability to different document types is improved, but model training time and computational resources increase

Engineering Contradiction:
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent performs preliminary action by training the probabilistic graphical model on a curated training corpus before deployment. During this offline training phase, the model learns document-specific patterns, token-class relationships, and contextual features. Once trained, the model can be rapidly applied to new documents of the same type without requiring additional training time. This preliminary training approach enables high adaptability to different document types while keeping inference time efficient.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11636287B2Learning form-based information classification
Publication Date: 2023.04.25
  • US11636287B2 patent drawing
  • US11636287B2 patent drawing
  • US11636287B2 patent drawing

AI summary

A method may include extracting training tokens from a training corpus, generating training token features and training contextual features for each of the training tokens, training a probabilistic graphical model using classes, the training token features, and the training contextual features, extracting, from actual data, actual tokens including an actual token, generating actual token features and actual contextual features for each of the actual tokens, and classifying the actual token as a class using the probabilistic graphical model, the actual token features, and the actual contextual features.