Files
pdf-inspector/napi
Abimael MartellandClaude Opus 4.6 7c8b09be67 fix: improve table detection for numeric columns and multi-line headers (#35)
* fix: improve heuristic table detection for numeric columns and multi-line headers

Two fixes for tables that have clean extractable text but fail heuristic
structure detection:

1. Numeric column merge pass (grid.rs): After initial X-position
   clustering, adjacent clusters are merged when one is sparse (header
   text) and the other is dense with >50% numeric items (data column).
   Multi-line wrapped headers often land slightly offset from their
   data column — the merge closes gaps within 1.5× the clustering
   threshold. New is_numeric_text() helper matches decimals, percentages,
   negative numbers, and comma-separated thousands.

2. Duplicate-header skip (detect_heuristic.rs): Spanning super-headers
   like "First Degree | First Degree | Higher Degree" contain duplicate
   cells that trigger looks_like_partial_table_ex rejection. Now skips
   rows with duplicate cells when a better header candidate exists
   within the next 3 rows (higher fill ratio or numeric cells).

Tested on BITS Pilani university report (430 pages, 314 table pages).
Page 4 (multi-line header + numeric data) previously returned
needs_ocr=true; now correctly detects the table structure.

Eval: 197 PDFs, zero regressions, all 104+ tests pass, zero clippy.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* bump version to 0.7.1

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 17:27:59 -07:00
..

firecrawl-pdf-inspector

Fast PDF classification and region-based text extraction for Node.js/Bun. Native Rust performance via napi-rs.

Built by Firecrawl for hybrid OCR pipelines — extract text from PDF structure where possible, fall back to OCR only when needed.

Install

npm install firecrawl-pdf-inspector
# or
bun add firecrawl-pdf-inspector

Prebuilt binaries included for linux-x64 and macOS ARM64. No Rust toolchain needed.

API

classifyPdf(buffer: Buffer): PdfClassification

Classify a PDF as TextBased, Scanned, Mixed, or ImageBased (~10-50ms). Returns which pages need OCR.

import { classifyPdf } from 'firecrawl-pdf-inspector'
import { readFileSync } from 'fs'

const pdf = readFileSync('document.pdf')
const result = classifyPdf(pdf)

console.log(result.pdfType)        // "TextBased" | "Scanned" | "Mixed" | "ImageBased"
console.log(result.pageCount)      // 42
console.log(result.pagesNeedingOcr) // [5, 12, 15] (0-indexed)
console.log(result.confidence)     // 0.875

extractTextInRegions(buffer: Buffer, pageRegions: PageRegions[]): PageRegionTexts[]

Extract text within bounding-box regions from a PDF. Designed for hybrid OCR pipelines where a layout model detects regions in rendered page images, and this function extracts text from the PDF structure for text-based pages — skipping GPU OCR.

Each region result includes a needsOcr flag that signals unreliable extraction (empty text, GID-encoded fonts, garbage text, encoding issues).

import { extractTextInRegions } from 'firecrawl-pdf-inspector'

const result = extractTextInRegions(pdf, [
  {
    page: 0, // 0-indexed
    regions: [
      [0, 0, 300, 400],    // [x1, y1, x2, y2] in PDF points, top-left origin
      [300, 0, 612, 400],
    ]
  }
])

for (const region of result[0].regions) {
  if (region.needsOcr) {
    // Unreliable text — send this region to OCR instead
  } else {
    console.log(region.text) // Extracted text in reading order
  }
}

Types

interface PdfClassification {
  pdfType: string          // "TextBased" | "Scanned" | "Mixed" | "ImageBased"
  pageCount: number
  pagesNeedingOcr: number[] // 0-indexed page numbers
  confidence: number        // 0.0 - 1.0
}

interface PageRegions {
  page: number              // 0-indexed
  regions: number[][]       // [[x1, y1, x2, y2], ...] in PDF points, top-left origin
}

interface PageRegionTexts {
  page: number
  regions: RegionText[]
}

interface RegionText {
  text: string
  needsOcr: boolean         // true when text is unreliable
}

Platforms

Platform Architecture Supported
Linux x64 Yes
macOS ARM64 Yes

License

MIT