Semantic Data Extraction

The process of extracting structured, meaningful data from unstructured or semi-structured sources such as images, documents, web pages, or natural language text, preserving the semantic relationships between data elements. In accessibility, semantic data extraction is used to convert visually-encoded content (like restaurant menus presented as images) into structured formats (like JSON objects with item names, descriptions, prices, and dietary attributes) that can be rendered in accessible interfaces. Modern approaches use multimodal large language models with carefully crafted prompts (including Chain-of-Thought reasoning) to identify entities, relationships, and hierarchical structure in visual documents. The quality of extraction directly impacts the accessibility of the resulting interface.