feat: add extractTablesInRegions NAPI binding for region-based table extraction (#27)

Adds a new function that takes a PDF buffer and page+bbox regions (same interface
as extractTextInRegions), runs heuristic table detection on items within each region,
and returns markdown pipe-tables. Falls back to needs_ocr=true when no table
structure is found or text quality is suspect.

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

napi/package.json

@@ -1,6 +1,6 @@
 {
   "name": "firecrawl-pdf-inspector",
-  "version": "0.3.6",
+  "version": "0.3.7",
   "description": "Fast PDF classification and text extraction. Detect text-based vs scanned PDFs, extract text by region with quality checks. Native Rust performance via napi-rs.",
   "main": "index.js",
   "types": "index.d.ts",

napi/src/lib.rs

@@ -255,7 +255,42 @@ pub fn extract_text_in_regions(
     page_regions: Vec<PageRegions>,
 ) -> Result<Vec<PageRegionTexts>> {
     let bytes: Vec<u8> = buffer.to_vec();
-    let regions: Vec<(u32, Vec<[f32; 4]>)> = page_regions
+    let regions = parse_page_regions(&page_regions);
+
+    catch_panic("extract_text_in_regions", move || {
+        let results = pdf_inspector::extract_text_in_regions_mem(&bytes, &regions)
+            .map_err(|e| to_napi_err(e, "extract_text_in_regions"))?;
+        Ok(to_page_region_texts(results))
+    })
+}
+
+/// Extract markdown tables within bounding-box regions from a PDF.
+///
+/// Like `extractTextInRegions` but runs table detection on items within each
+/// region and returns markdown pipe-tables instead of flat text.
+///
+/// When table structure is detected, `text` contains a markdown pipe-table and
+/// `needsOcr` is `false`. When no table is found, `text` is empty and
+/// `needsOcr` is `true` so the caller can fall back to GPU OCR.
+///
+/// Coordinates are PDF points with top-left origin.
+#[napi]
+pub fn extract_tables_in_regions(
+    buffer: Buffer,
+    page_regions: Vec<PageRegions>,
+) -> Result<Vec<PageRegionTexts>> {
+    let bytes: Vec<u8> = buffer.to_vec();
+    let regions = parse_page_regions(&page_regions);
+
+    catch_panic("extract_tables_in_regions", move || {
+        let results = pdf_inspector::extract_tables_in_regions_mem(&bytes, &regions)
+            .map_err(|e| to_napi_err(e, "extract_tables_in_regions"))?;
+        Ok(to_page_region_texts(results))
+    })
+}
+
+fn parse_page_regions(page_regions: &[PageRegions]) -> Vec<(u32, Vec<[f32; 4]>)> {
+    page_regions
         .iter()
         .map(|pr| {
             let bboxes: Vec<[f32; 4]> = pr
@@ -271,13 +306,11 @@ pub fn extract_text_in_regions(
                 .collect();
             (pr.page, bboxes)
         })
-        .collect();
+        .collect()
+}
 
-    catch_panic("extract_text_in_regions", move || {
-        let results = pdf_inspector::extract_text_in_regions_mem(&bytes, &regions)
-            .map_err(|e| to_napi_err(e, "extract_text_in_regions"))?;
-
-        Ok(results
+fn to_page_region_texts(results: Vec<pdf_inspector::PageRegionResult>) -> Vec<PageRegionTexts> {
+    results
         .into_iter()
         .map(|page_result| PageRegionTexts {
             page: page_result.page,
@@ -290,6 +323,5 @@ pub fn extract_text_in_regions(
                 })
                 .collect(),
         })
-            .collect())
-    })
+        .collect()
 }

src/lib.rs

@@ -444,6 +444,155 @@ pub fn extract_text_in_regions_mem(
     Ok(results)
 }
 
+/// Extract tables within bounding-box regions from a PDF in memory.
+///
+/// Similar to [`extract_text_in_regions_mem`] but runs table detection on items
+/// within each region and returns markdown pipe-tables instead of flat text.
+///
+/// When table structure is detected, `text` contains a markdown pipe-table and
+/// `needs_ocr` is `false`. When no table is found (too few items, poor alignment,
+/// GID fonts, etc.), `text` is empty and `needs_ocr` is `true` so the caller can
+/// fall back to GPU OCR.
+pub fn extract_tables_in_regions_mem(
+    buffer: &[u8],
+    page_regions: &[(u32, Vec<[f32; 4]>)],
+) -> Result<Vec<PageRegionResult>, PdfError> {
+    validate_pdf_bytes(buffer)?;
+    let (doc, _page_count) = load_document_from_mem(buffer)?;
+    let pages = doc.get_pages();
+
+    let needed_pages: HashSet<u32> = page_regions.iter().map(|(p, _)| p + 1).collect();
+    let font_cmaps = FontCMaps::from_doc_pages_fast(&doc, Some(&needed_pages));
+
+    let mut items_by_page: HashMap<u32, Vec<TextItem>> = HashMap::new();
+    let mut page_heights: HashMap<u32, f32> = HashMap::new();
+    let mut gid_pages: HashSet<u32> = HashSet::new();
+    let mut page_thresholds: HashMap<u32, f32> = HashMap::new();
+    let mut rotated_pages: HashSet<u32> = HashSet::new();
+
+    for (page_num, &page_id) in pages.iter() {
+        if !needed_pages.contains(page_num) {
+            continue;
+        }
+        let height = get_page_height(&doc, page_id).unwrap_or(792.0);
+        page_heights.insert(*page_num, height);
+
+        let ((mut items, _rects, _lines), has_gid, coords_rotated) =
+            extractor::content_stream::extract_page_text_items(
+                &doc,
+                page_id,
+                *page_num,
+                &font_cmaps,
+                false,
+            )?;
+        let threshold = text_utils::fix_letterspaced_items(&mut items);
+        if threshold > 0.10 {
+            page_thresholds.insert(*page_num, threshold);
+        }
+        if has_gid {
+            gid_pages.insert(*page_num);
+        }
+        if coords_rotated {
+            rotated_pages.insert(*page_num);
+        }
+        items_by_page.insert(*page_num, items);
+    }
+
+    let mut results = Vec::with_capacity(page_regions.len());
+
+    for (page_0idx, regions) in page_regions {
+        let page_1idx = page_0idx + 1;
+        let items = items_by_page.get(&page_1idx);
+        let page_h = page_heights.get(&page_1idx).copied().unwrap_or(792.0);
+        let page_has_gid = gid_pages.contains(&page_1idx);
+        let coords = if rotated_pages.contains(&page_1idx) {
+            RegionCoordSpace::Rotated90Ccw
+        } else {
+            RegionCoordSpace::Standard
+        };
+
+        let mut page_results = Vec::with_capacity(regions.len());
+
+        for rect in regions {
+            let [rx1, ry1, rx2, ry2] = *rect;
+
+            // If page has GID font issues, bail early
+            if page_has_gid {
+                page_results.push(RegionText {
+                    text: String::new(),
+                    needs_ocr: true,
+                });
+                continue;
+            }
+
+            let matched: Vec<TextItem> = match items {
+                Some(items) => {
+                    let bounds = region_bounds(rx1, ry1, rx2, ry2, page_h, coords);
+                    items
+                        .iter()
+                        .filter(|item| region_overlaps_item(item, bounds))
+                        .cloned()
+                        .collect()
+                }
+                None => Vec::new(),
+            };
+
+            if matched.is_empty() {
+                page_results.push(RegionText {
+                    text: String::new(),
+                    needs_ocr: true,
+                });
+                continue;
+            }
+
+            // Compute base_font_size as most common font size in the region
+            let base_font_size = {
+                let mut freq: HashMap<i32, usize> = HashMap::new();
+                for item in &matched {
+                    *freq.entry((item.font_size * 10.0) as i32).or_default() += 1;
+                }
+                freq.into_iter()
+                    .max_by_key(|(_, count)| *count)
+                    .map(|(size, _)| size as f32 / 10.0)
+                    .unwrap_or(12.0)
+            };
+
+            // Run heuristic table detection; skip_body_font = false since
+            // the layout model already identified this region as a table.
+            let detected = tables::detect_tables(&matched, base_font_size, false);
+
+            if let Some(table) = detected.into_iter().next() {
+                let md = tables::table_to_markdown(&table);
+                if md.trim().is_empty() {
+                    page_results.push(RegionText {
+                        text: String::new(),
+                        needs_ocr: true,
+                    });
+                } else {
+                    let needs_ocr =
+                        is_garbage_text(&md) || is_cid_garbage(&md) || detect_encoding_issues(&md);
+                    page_results.push(RegionText {
+                        text: md,
+                        needs_ocr,
+                    });
+                }
+            } else {
+                page_results.push(RegionText {
+                    text: String::new(),
+                    needs_ocr: true,
+                });
+            }
+        }
+
+        results.push(PageRegionResult {
+            page: *page_0idx,
+            regions: page_results,
+        });
+    }
+
+    Ok(results)
+}
+
 /// Get page height in points from MediaBox.
 fn get_page_height(doc: &Document, page_id: lopdf::ObjectId) -> Option<f32> {
     let page_dict = doc.get_dictionary(page_id).ok()?;

tests/integration_tests.rs

@@ -4,9 +4,9 @@ use pdf_inspector::detector::{DetectionConfig, ScanStrategy};
 use pdf_inspector::extractor::group_into_lines;
 use pdf_inspector::types::TextLine;
 use pdf_inspector::{
-    detect_pdf_type, extract_text, extract_text_in_regions_mem, extract_text_with_positions,
-    process_pdf_mem, process_pdf_with_options, to_markdown, MarkdownOptions, PdfError, PdfOptions,
-    PdfType, TextItem,
+    detect_pdf_type, extract_tables_in_regions_mem, extract_text, extract_text_in_regions_mem,
+    extract_text_with_positions, process_pdf_mem, process_pdf_with_options, to_markdown,
+    MarkdownOptions, PdfError, PdfOptions, PdfType, TextItem,
 };
 use std::collections::HashSet;
 
@@ -1344,3 +1344,95 @@ fn test_extract_regions_fast_vs_normal_comparison() {
         }
     }
 }
+
+// =========================================================================
+// extract_tables_in_regions_mem tests
+// =========================================================================
+
+#[test]
+fn test_extract_tables_in_regions_table_pdf() {
+    // tnagriculture has a clear table with district names and spice columns
+    let buf = std::fs::read("tests/fixtures/tnagriculture_06_12.pdf").unwrap();
+    let results =
+        extract_tables_in_regions_mem(&buf, &[(0, vec![[0.0, 0.0, 1200.0, 1200.0]])]).unwrap();
+
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].regions.len(), 1);
+
+    let region = &results[0].regions[0];
+    // Should detect a table with pipe-delimited markdown
+    if !region.needs_ocr {
+        assert!(
+            region.text.contains('|'),
+            "Table output should contain pipe delimiters"
+        );
+        // Should have separator row
+        assert!(
+            region.text.lines().any(|l| l.contains("---")),
+            "Table output should contain separator row"
+        );
+    }
+}
+
+#[test]
+fn test_extract_tables_in_regions_non_table_region() {
+    // Use a small region that likely won't contain enough items for a table
+    let buf = std::fs::read("tests/fixtures/nexo-price-en.pdf").unwrap();
+    let results =
+        extract_tables_in_regions_mem(&buf, &[(0, vec![[0.0, 0.0, 50.0, 50.0]])]).unwrap();
+
+    assert_eq!(results.len(), 1);
+    assert_eq!(results[0].regions.len(), 1);
+
+    let region = &results[0].regions[0];
+    // Small region with few items should fall back to needs_ocr
+    assert!(
+        region.needs_ocr,
+        "Non-table region should set needs_ocr = true"
+    );
+    assert!(
+        region.text.is_empty(),
+        "Non-table region should have empty text"
+    );
+}
+
+#[test]
+fn test_extract_tables_in_regions_empty_region() {
+    let buf = std::fs::read("tests/fixtures/nexo-price-en.pdf").unwrap();
+    let results = extract_tables_in_regions_mem(&buf, &[(0, vec![[0.0, 0.0, 0.0, 0.0]])]).unwrap();
+
+    assert_eq!(results.len(), 1);
+    let region = &results[0].regions[0];
+    assert!(region.needs_ocr);
+    assert!(region.text.is_empty());
+}
+
+#[test]
+fn test_extract_tables_in_regions_identity_h_needs_ocr() {
+    let buf = std::fs::read("tests/fixtures/shinagawa_identity_h.pdf").unwrap();
+    let results =
+        extract_tables_in_regions_mem(&buf, &[(0, vec![[0.0, 0.0, 1200.0, 1200.0]])]).unwrap();
+
+    assert_eq!(results.len(), 1);
+    let region = &results[0].regions[0];
+    assert!(region.needs_ocr, "Identity-H font should trigger needs_ocr");
+}
+
+#[test]
+fn test_extract_tables_in_regions_not_a_pdf() {
+    let result =
+        extract_tables_in_regions_mem(b"not a pdf", &[(0, vec![[0.0, 0.0, 100.0, 100.0]])]);
+    assert!(result.is_err());
+}
+
+#[test]
+fn test_extract_tables_in_regions_nonexistent_page() {
+    let buf = std::fs::read("tests/fixtures/nexo-price-en.pdf").unwrap();
+    let results =
+        extract_tables_in_regions_mem(&buf, &[(9999, vec![[0.0, 0.0, 1200.0, 1200.0]])]).unwrap();
+
+    assert_eq!(results.len(), 1);
+    let region = &results[0].regions[0];
+    assert!(region.needs_ocr);
+    assert!(region.text.is_empty());
+}