Bump napi package version to 0.3.3

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

Cargo.toml

@@ -17,7 +17,7 @@ crate-type = ["lib", "cdylib"]
 pyo3 = { version = "0.25", features = ["extension-module"], optional = true }
 
 # PDF parsing
-lopdf = { git = "https://github.com/J-F-Liu/lopdf", rev = "052674053814a9f4897af94f0b8e46a545c9b329", features = ["rayon"] }
+lopdf = { git = "https://github.com/J-F-Liu/lopdf", rev = "7a05512d831415b1f2b1ce522391d6beab8a1284", features = ["rayon"] }
 
 # Error handling
 thiserror = "2.0"

README.md

@@ -16,6 +16,23 @@ Built by [Firecrawl](https://firecrawl.dev) to handle text-based PDFs locally in
 - **Single document load** — The document is parsed once and shared between detection and extraction, avoiding redundant I/O.
 - **Lightweight** — Pure Rust, no ML models, no external services. Single dependency on `lopdf` for PDF parsing.
 
+## Benchmark
+
+Evaluated on the [opendataloader-bench](https://github.com/opendataloader-project/opendataloader-bench) corpus (200 PDFs). Only direct text extraction engines are shown — no OCR, no ML models. Scores are 0-1, higher is better.
+
+| Engine | Overall | Reading Order (NID) | Tables (TEDS) | Headings (MHS) | Speed (200 docs) |
+|---|---|---|---|---|---|
+| pdf-inspector | 0.77 | 0.87 | 0.52 | 0.58 | 4s |
+| opendataloader | 0.84 | 0.91 | 0.49 | 0.74 | 11s |
+| pymupdf4llm | 0.73 | 0.89 | 0.40 | 0.41 | 18s |
+| markitdown | 0.58 | 0.88 | 0.00 | 0.00 | 8s |
+
+For context, engines that use OCR/ML (docling, marker, mineru) score 0.83-0.88 overall but take 2-180 minutes on the same corpus.
+
+**Where we do well:** Speed (fastest of all engines), reading order, table detection vs other direct-text tools.
+
+**Where we lag:** Heading detection trails opendataloader — many PDFs use bold text at body font size for headings, or headings that are only slightly larger than body text. Table detection trails OCR-based engines that can see visual table structure.
+
 ## Quick start
 
 ### Python

napi/package.json

@@ -1,6 +1,6 @@
 {
   "name": "firecrawl-pdf-inspector",
-  "version": "0.3.2",
+  "version": "0.3.3",
   "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",

src/extractor/content_stream.rs

@@ -82,7 +82,7 @@ pub(crate) fn extract_page_text_items(
     page_num: u32,
     font_cmaps: &FontCMaps,
     include_invisible: bool,
-) -> Result<(PageExtraction, bool), PdfError> {
+) -> Result<(PageExtraction, bool, bool), PdfError> {
     use lopdf::content::Content;
 
     let mut items = Vec::new();
@@ -182,7 +182,7 @@ pub(crate) fn extract_page_text_items(
             content.operations.len(),
             MAX_OPERATIONS
         );
-        return Ok(((Vec::new(), Vec::new(), Vec::new()), false));
+        return Ok(((Vec::new(), Vec::new(), Vec::new()), false, false));
     }
 
     // Graphics state tracking
@@ -1009,11 +1009,12 @@ pub(crate) fn extract_page_text_items(
     // Some PDFs embed landscape content in portrait pages using a rotated text
     // matrix (e.g. [0, b, -b, 0, tx, ty] for 90° CCW).  The layout engine
     // assumes x=horizontal, y=vertical — so we swap coordinates to match.
-    let (items, rects, lines) = correct_rotated_page(items, rects, lines, &rotation_votes);
+    let (items, rects, lines, coords_rotated) =
+        correct_rotated_page(items, rects, lines, &rotation_votes);
 
     let items = super::merge_text_items(items);
     let items = super::merge_subscript_items(items);
-    Ok(((items, rects, lines), has_gid_fonts))
+    Ok(((items, rects, lines), has_gid_fonts, coords_rotated))
 }
 
 /// Counts of text operators with horizontal vs rotated combined matrices.
@@ -1030,9 +1031,9 @@ fn correct_rotated_page(
     mut rects: Vec<PdfRect>,
     mut lines: Vec<PdfLine>,
     votes: &RotationVotes,
-) -> (Vec<TextItem>, Vec<PdfRect>, Vec<PdfLine>) {
+) -> (Vec<TextItem>, Vec<PdfRect>, Vec<PdfLine>, bool) {
     if items.len() < 2 {
-        return (items, rects, lines);
+        return (items, rects, lines, false);
     }
 
     // Use the combined-matrix direction votes collected during extraction.
@@ -1041,7 +1042,7 @@ fn correct_rotated_page(
     let total_votes = votes.horizontal + votes.rotated;
     if total_votes == 0 || votes.rotated * 3 < total_votes * 2 {
         // Less than ~67% of text operators are rotated → not a rotated page
-        return (items, rects, lines);
+        return (items, rects, lines, false);
     }
 
     log::debug!(
@@ -1092,7 +1093,7 @@ fn correct_rotated_page(
         line.y2 = new_y2;
     }
 
-    (items, rects, lines)
+    (items, rects, lines, true)
 }
 
 /// Remove near-duplicate rects (same coordinates within 0.5 pt tolerance).
@@ -1228,7 +1229,7 @@ mod tests {
 
         let font_cmaps = FontCMaps::from_doc(&doc);
         let result = extract_page_text_items(&doc, page_id, 1, &font_cmaps, false).unwrap();
-        let ((items, rects, lines), _has_gid) = result;
+        let ((items, rects, lines), _has_gid, _coords_rotated) = result;
         assert!(items.is_empty());
         assert!(rects.is_empty());
         assert!(lines.is_empty());

src/extractor/layout.rs

@@ -35,6 +35,7 @@ pub(crate) fn detect_columns(
     if page_items.is_empty() {
         return vec![];
     }
+    debug!("page {}: detect_columns: {} items", page, page_items.len());
 
     // Find page bounds
     let x_min = page_items.iter().map(|i| i.x).fold(f32::INFINITY, f32::min);
@@ -166,6 +167,23 @@ pub(crate) fn detect_columns(
         return vec![ColumnRegion { x_min, x_max }];
     }
 
+    // Try center-based assignment first (handles asymmetric layouts / sidebars
+    // better than edge-based). Fall back to edge-based if center produces
+    // a degenerate split (one side empty).
+    let result = validate_and_build_columns(
+        &valleys,
+        &page_items,
+        x_min,
+        BIN_WIDTH,
+        x_max,
+        MIN_ITEMS_PER_COLUMN,
+        MIN_VERTICAL_SPAN_RATIO,
+        page,
+        true, // center-based assignment
+    );
+    if result.len() > 1 {
+        return result;
+    }
     return validate_and_build_columns(
         &valleys,
         &page_items,
@@ -175,7 +193,7 @@ pub(crate) fn detect_columns(
         MIN_ITEMS_PER_COLUMN,
         MIN_VERTICAL_SPAN_RATIO,
         page,
-        false, // edge-based assignment for absolute valleys
+        false, // edge-based fallback
     );
 }
 
@@ -505,7 +523,15 @@ fn validate_and_build_columns(
             })
             .collect();
 
-        if left_items.len() < min_items || right_items.len() < min_items {
+        // Require both sides to have items. Symmetric layout needs min_items
+        // on each side. Asymmetric layouts (sidebars) are accepted when the
+        // dominant side has ≥ min_items and the smaller side has ≥ 3 items.
+        let (smaller, larger) = if left_items.len() <= right_items.len() {
+            (left_items.len(), right_items.len())
+        } else {
+            (right_items.len(), left_items.len())
+        };
+        if larger < min_items || smaller < 3 {
             continue;
         }
 

src/extractor/mod.rs

@@ -188,7 +188,7 @@ fn extract_positioned_text_impl(
                 continue;
             }
         }
-        let ((mut items, rects, lines), has_gid_fonts) =
+        let ((mut items, rects, lines), has_gid_fonts, _coords_rotated) =
             extract_page_text_items(doc, page_id, *page_num, font_cmaps, include_invisible)?;
         if has_gid_fonts {
             gid_encoded_pages.insert(*page_num);

src/lib.rs

@@ -358,6 +358,8 @@ pub fn extract_text_in_regions_mem(
     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) {
@@ -369,7 +371,7 @@ pub fn extract_text_in_regions_mem(
         page_heights.insert(*page_num, height);
 
         // Extract text items for this page
-        let ((mut items, _rects, _lines), has_gid) =
+        let ((mut items, _rects, _lines), has_gid, coords_rotated) =
             extractor::content_stream::extract_page_text_items(
                 &doc,
                 page_id,
@@ -377,10 +379,16 @@ pub fn extract_text_in_regions_mem(
                 &font_cmaps,
                 false,
             )?;
-        text_utils::fix_letterspaced_items(&mut items);
+        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);
     }
 
@@ -392,6 +400,12 @@ pub fn extract_text_in_regions_mem(
         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 adaptive_threshold = page_thresholds.get(&page_1idx).copied().unwrap_or(0.10);
+        let coords = if rotated_pages.contains(&page_1idx) {
+            RegionCoordSpace::Rotated90Ccw
+        } else {
+            RegionCoordSpace::Standard
+        };
 
         let mut page_results = Vec::with_capacity(regions.len());
 
@@ -399,7 +413,16 @@ pub fn extract_text_in_regions_mem(
             let [rx1, ry1, rx2, ry2] = *rect;
 
             let text = match items {
-                Some(items) => collect_text_in_region(items, rx1, ry1, rx2, ry2, page_h),
+                Some(items) => collect_text_in_region_with_options(
+                    items,
+                    rx1,
+                    ry1,
+                    rx2,
+                    ry2,
+                    page_h,
+                    coords,
+                    adaptive_threshold,
+                ),
                 None => String::new(),
             };
 
@@ -454,6 +477,20 @@ fn obj_to_f32(obj: &lopdf::Object) -> Option<f32> {
     }
 }
 
+#[derive(Clone, Copy)]
+enum RegionCoordSpace {
+    Standard,
+    Rotated90Ccw,
+}
+
+#[derive(Clone, Copy)]
+struct RegionBounds {
+    x_min: f32,
+    y_min: f32,
+    x_max: f32,
+    y_max: f32,
+}
+
 /// Collect text items that fall within a region bbox (top-left origin, PDF points)
 /// and return them as a single string in reading order.
 pub fn collect_text_in_region(
@@ -464,65 +501,109 @@ pub fn collect_text_in_region(
     ry2: f32,
     page_height: f32,
 ) -> String {
-    // Convert region from top-left to bottom-left origin
-    let by1 = page_height - ry2; // top-left y2 → bottom-left y1
-    let by2 = page_height - ry1; // top-left y1 → bottom-left y2
+    collect_text_in_region_with_options(
+        items,
+        rx1,
+        ry1,
+        rx2,
+        ry2,
+        page_height,
+        infer_region_coord_space(items),
+        0.10,
+    )
+}
 
-    // Collect items whose center falls within the region
-    let mut matched: Vec<&TextItem> = items
+#[allow(clippy::too_many_arguments)]
+fn collect_text_in_region_with_options(
+    items: &[TextItem],
+    rx1: f32,
+    ry1: f32,
+    rx2: f32,
+    ry2: f32,
+    page_height: f32,
+    coord_space: RegionCoordSpace,
+    adaptive_threshold: f32,
+) -> String {
+    let bounds = region_bounds(rx1, ry1, rx2, ry2, page_height, coord_space);
+    let Some(page) = items.first().map(|item| item.page) else {
+        return String::new();
+    };
+    let matched: Vec<TextItem> = items
         .iter()
-        .filter(|item| {
-            let cx = item.x + item.width / 2.0;
-            let cy = item.y + item.height / 2.0;
-            cx >= rx1 && cx <= rx2 && cy >= by1 && cy <= by2
-        })
+        .filter(|item| region_overlaps_item(item, bounds))
+        .cloned()
         .collect();
-
     if matched.is_empty() {
         return String::new();
     }
-
-    // Sort top→bottom (descending Y in bottom-left coords), then left→right.
-    // Uses strict total_cmp ordering to guarantee transitivity (required by
-    // Rust's sort). The line-grouping phase below handles fuzzy Y matching.
-    matched.sort_by(|a, b| {
-        b.y.total_cmp(&a.y) // descending Y = top to bottom
-            .then(a.x.total_cmp(&b.x)) // ascending X = left to right
-    });
-
-    // Group into lines and join
-    let mut lines: Vec<String> = Vec::new();
-    let mut current_line = String::new();
-    let mut last_y = f32::NAN;
-    let mut last_x_end = 0.0_f32;
-
-    for item in &matched {
-        let line_threshold = item.font_size * 0.5;
-        let same_line = (item.y - last_y).abs() < line_threshold;
-
-        if !same_line && !current_line.is_empty() {
-            lines.push(current_line.clone());
-            current_line.clear();
-        }
-
-        if !current_line.is_empty() {
-            // Insert space if there's a gap between items on the same line
-            let gap = item.x - last_x_end;
-            if gap > item.font_size * 0.15 {
-                current_line.push(' ');
-            }
-        }
-
-        current_line.push_str(&item.text);
-        last_y = item.y;
-        last_x_end = item.x + item.width;
+    let mut thresholds = HashMap::new();
+    if adaptive_threshold > 0.10 {
+        thresholds.insert(page, adaptive_threshold);
     }
+    let lines = extractor::group_into_lines_with_thresholds(matched, &thresholds, &HashSet::new());
+    lines
+        .into_iter()
+        .map(|line| line.text())
+        .collect::<Vec<_>>()
+        .join("\n")
+}
 
-    if !current_line.is_empty() {
-        lines.push(current_line);
+fn infer_region_coord_space(items: &[TextItem]) -> RegionCoordSpace {
+    // Rotated-page normalization currently maps y = -old_x, so most text items
+    // land at negative Y. Use this to keep `collect_text_in_region` behavior
+    // compatible for direct callers that do not have extractor metadata.
+    let negative_y = items.iter().filter(|item| item.y < 0.0).count();
+    if !items.is_empty() && negative_y * 2 >= items.len() {
+        RegionCoordSpace::Rotated90Ccw
+    } else {
+        RegionCoordSpace::Standard
     }
+}
 
-    lines.join("\n")
+fn region_bounds(
+    rx1: f32,
+    ry1: f32,
+    rx2: f32,
+    ry2: f32,
+    page_height: f32,
+    coord_space: RegionCoordSpace,
+) -> RegionBounds {
+    let tx_min = rx1.min(rx2);
+    let tx_max = rx1.max(rx2);
+    let ty_min = ry1.min(ry2);
+    let ty_max = ry1.max(ry2);
+    let by_min = page_height - ty_max;
+    let by_max = page_height - ty_min;
+    match coord_space {
+        RegionCoordSpace::Standard => RegionBounds {
+            x_min: tx_min,
+            y_min: by_min,
+            x_max: tx_max,
+            y_max: by_max,
+        },
+        RegionCoordSpace::Rotated90Ccw => RegionBounds {
+            x_min: by_min,
+            x_max: by_max,
+            y_min: -tx_max,
+            y_max: -tx_min,
+        },
+    }
+}
+
+fn region_overlaps_item(item: &TextItem, bounds: RegionBounds) -> bool {
+    const REGION_MARGIN: f32 = 1.5;
+    let item_x_min = item.x;
+    let item_x_max = item.x + text_utils::effective_width(item);
+    let item_y_min = item.y;
+    let item_y_max = item.y + item.height;
+
+    let x_overlap = (item_x_max.min(bounds.x_max + REGION_MARGIN)
+        - item_x_min.max(bounds.x_min - REGION_MARGIN))
+    .max(0.0);
+    let y_overlap = (item_y_max.min(bounds.y_max + REGION_MARGIN)
+        - item_y_min.max(bounds.y_min - REGION_MARGIN))
+    .max(0.0);
+    x_overlap > 0.0 && y_overlap > 0.0
 }
 
 // =========================================================================

src/markdown/analysis.rs

@@ -8,6 +8,24 @@ use log::debug;
 /// Font statistics for a document
 pub(crate) struct FontStats {
     pub(crate) most_common_size: f32,
+    /// Font size frequency distribution (size_key → line count).
+    /// Used for rarity-based heading detection.
+    pub(crate) size_counts: HashMap<i32, usize>,
+    /// Total number of lines counted.
+    pub(crate) total_lines: usize,
+}
+
+/// Compute how rare a font size is in the document (0.0 = most common, 1.0 = unique).
+/// Mirrors opendataloader's font rarity boosting approach: heading fonts appear on
+/// far fewer lines than body text, so their percentile rank is high.
+pub(crate) fn font_size_rarity(font_size: f32, stats: &FontStats) -> f32 {
+    if stats.total_lines == 0 {
+        return 0.0;
+    }
+    let key = (font_size * 10.0) as i32;
+    let count = stats.size_counts.get(&key).copied().unwrap_or(0);
+    // Rarity = 1 - (frequency ratio). A size used on 1/100 lines has rarity ~0.99.
+    1.0 - (count as f32 / stats.total_lines as f32)
 }
 
 /// Calculate font stats directly from items (before grouping into lines)
@@ -21,6 +39,8 @@ pub(crate) fn calculate_font_stats_from_items(items: &[TextItem]) -> FontStats {
         }
     }
 
+    let total_lines = size_counts.values().sum();
+
     // Break ties by preferring the smaller font size for deterministic output
     let most_common_size = size_counts
         .iter()
@@ -30,7 +50,11 @@ pub(crate) fn calculate_font_stats_from_items(items: &[TextItem]) -> FontStats {
         .map(|(size, _)| *size as f32 / 10.0)
         .unwrap_or(12.0);
 
-    FontStats { most_common_size }
+    FontStats {
+        most_common_size,
+        size_counts,
+        total_lines,
+    }
 }
 
 /// Calculate font stats from grouped lines
@@ -48,6 +72,8 @@ pub(crate) fn calculate_font_stats(lines: &[TextLine]) -> FontStats {
         }
     }
 
+    let total_lines = size_counts.values().sum();
+
     // Break ties by preferring the smaller font size for deterministic output
     let most_common_size = size_counts
         .iter()
@@ -57,7 +83,23 @@ pub(crate) fn calculate_font_stats(lines: &[TextLine]) -> FontStats {
         .map(|(size, _)| *size as f32 / 10.0)
         .unwrap_or(12.0);
 
-    FontStats { most_common_size }
+    FontStats {
+        most_common_size,
+        size_counts,
+        total_lines,
+    }
+}
+
+/// Determine the heading level for a bold-only line that didn't meet the font-size
+/// threshold.  These are common in academic papers where section headings are bold
+/// at the same size as body text.
+///
+/// Returns a level below the lowest font-size tier (or H2 when no tiers exist).
+pub(crate) fn bold_heading_level(heading_tiers: &[f32]) -> usize {
+    let level = heading_tiers.len() + 1;
+    // Clamp to 1..=6 — if no font-size tiers, bold headings become H2
+    // (H1 is reserved for titles which are typically larger)
+    level.clamp(2, 6)
 }
 
 /// Detect TOC-style lines that contain dot leaders (e.g., "Section Name .... 42").

src/markdown/classify.rs

@@ -4,13 +4,11 @@
 pub(crate) fn is_caption_line(text: &str) -> bool {
     let trimmed = text.trim();
 
-    // Common caption prefixes in multiple languages
-    let caption_prefixes = [
-        "Figure ",
+    // Caption prefixes that always match (always followed by identifiers)
+    let always_prefixes = [
         "Figura ",
         "Fig. ",
         "Fig ",
-        "Table ",
         "Tabela ",
         "Source:",
         "Fonte:",
@@ -27,17 +25,39 @@ pub(crate) fn is_caption_line(text: &str) -> bool {
         "Photo ",
         "Foto ",
     ];
-
-    // Check if line starts with a caption prefix
-    for prefix in &caption_prefixes {
+    for prefix in &always_prefixes {
         if trimmed.starts_with(prefix) {
             return true;
         }
     }
 
-    // Check case-insensitive patterns
+    // "Figure" and "Table" need a digit/reference after them to distinguish
+    // captions ("Table 1", "Figure 3.2") from headings ("Table of Contents")
+    for prefix in ["Figure ", "Table "] {
+        if let Some(rest) = trimmed.strip_prefix(prefix) {
+            if rest
+                .trim_start()
+                .starts_with(|c: char| c.is_ascii_digit() || c == '(' || c == '#')
+            {
+                return true;
+            }
+        }
+    }
+
+    // Check case-insensitive patterns — require digit or punctuation after
+    // prefix to avoid matching "Table of Contents" or "Figure drawing" etc.
     let lower = trimmed.to_lowercase();
-    if lower.starts_with("figure ") || lower.starts_with("table ") || lower.starts_with("source:") {
+    for pfx in ["figure ", "table "] {
+        if let Some(rest) = lower.strip_prefix(pfx) {
+            if rest
+                .trim_start()
+                .starts_with(|c: char| c.is_ascii_digit() || c == '(' || c == '#')
+            {
+                return true;
+            }
+        }
+    }
+    if lower.starts_with("source:") {
         return true;
     }
 

src/markdown/convert.rs

@@ -6,8 +6,8 @@ use crate::structure_tree::StructRole;
 use crate::types::TextLine;
 
 use super::analysis::{
-    calculate_font_stats, compute_heading_tiers, compute_paragraph_threshold, detect_header_level,
-    has_dot_leaders,
+    bold_heading_level, calculate_font_stats, compute_heading_tiers, compute_paragraph_threshold,
+    detect_header_level, font_size_rarity, has_dot_leaders,
 };
 use super::classify::{format_list_item, is_caption_line, is_list_item, is_monospace_font};
 use super::postprocess::clean_markdown;
@@ -443,7 +443,33 @@ pub(super) fn to_markdown_from_lines_with_tables_and_images(
             && plain_trimmed.split_whitespace().count() <= 15
         {
             let line_font_size = line.items.first().map(|i| i.font_size).unwrap_or(base_size);
-            detect_header_level(line_font_size, base_size, &heading_tiers)
+            detect_header_level(line_font_size, base_size, &heading_tiers).or_else(|| {
+                // Rarity-based heading detection (inspired by opendataloader).
+                // Score = font_rarity * 0.5 + bold * 0.3 + standalone * 0.2
+                // Lines scoring above threshold are promoted to headings.
+                // Only consider lines at or above body font size.
+                if line_font_size < base_size * 0.95 {
+                    return None;
+                }
+                let word_count = plain_trimmed.split_whitespace().count();
+                if !(1..=15).contains(&word_count) {
+                    return None;
+                }
+                let rarity = font_size_rarity(line_font_size, &font_stats);
+                let all_bold = !line.items.is_empty() && line.items.iter().all(|i| i.is_bold);
+                let standalone = !in_paragraph;
+
+                let score = rarity * 0.5
+                    + if all_bold { 0.3 } else { 0.0 }
+                    + if standalone { 0.2 } else { 0.0 };
+
+                // Require standalone + at least one other signal
+                if score >= 0.5 && standalone && word_count >= 3 {
+                    Some(bold_heading_level(&heading_tiers))
+                } else {
+                    None
+                }
+            })
         } else {
             None
         };
@@ -699,7 +725,25 @@ pub fn to_markdown_from_lines(lines: Vec<TextLine>, options: MarkdownOptions) ->
         {
             let line_font_size = line.items.first().map(|i| i.font_size).unwrap_or(base_size);
             if let Some(header_level) =
-                detect_header_level(line_font_size, base_size, &heading_tiers)
+                detect_header_level(line_font_size, base_size, &heading_tiers).or_else(|| {
+                    if line_font_size < base_size * 0.95 {
+                        return None;
+                    }
+                    let word_count = plain_trimmed.split_whitespace().count();
+                    if !(1..=15).contains(&word_count) {
+                        return None;
+                    }
+                    let rarity = font_size_rarity(line_font_size, &font_stats);
+                    let all_bold = !line.items.is_empty() && line.items.iter().all(|i| i.is_bold);
+                    let standalone = !in_paragraph;
+                    let score = rarity * 0.5
+                        + if all_bold { 0.3 } else { 0.0 }
+                        + if standalone { 0.2 } else { 0.0 };
+                    if score >= 0.5 && standalone && word_count >= 3 {
+                        return Some(bold_heading_level(&heading_tiers));
+                    }
+                    None
+                })
             {
                 if in_paragraph {
                     output.push_str("\n\n");

src/markdown/mod.rs

@@ -601,6 +601,15 @@ pub(crate) fn to_markdown_from_items_with_rects_and_lines(
         let group = page_groups.get(&page).unwrap();
         let page_items: Vec<TextItem> = group.iter().map(|(_, item)| (*item).clone()).collect();
 
+        // Detect columns early — on multi-column pages, the merged-band retry
+        // should skip body-font heuristic table detection (which mistakes column
+        // text for tables). Individual band heuristic detection is left enabled
+        // because bands are scoped to single columns.
+        let page_has_columns = {
+            let cols = crate::extractor::detect_columns(&page_items, page, false);
+            cols.len() >= 2
+        };
+
         // Check for side-by-side layout (e.g. two tables placed left and right)
         let mut bands = split_side_by_side(&page_items);
         // Fallback: use rect hint regions to detect side-by-side layout
@@ -873,10 +882,7 @@ pub(crate) fn to_markdown_from_items_with_rects_and_lines(
                 run_heuristic(&unclaimed_items, &unclaimed_map, 6);
             }
 
-            // 4. Column-based table detection: last resort for borderless tabular
-            //    layouts (e.g. exam/reference grids) when ALL structural methods
-            //    found nothing. Only runs when no rects/lines exist (truly borderless)
-            //    and no other detection method found tables in this band.
+            // 4. Column-based table detection for borderless tabular layouts.
             let band_has_tables = band_items.iter().enumerate().any(|(idx, _)| {
                 band_index_map
                     .get(idx)
@@ -903,6 +909,65 @@ pub(crate) fn to_markdown_from_items_with_rects_and_lines(
             }
         }
 
+        // 5. Thin-rect border synthesis: last resort for PDFs that draw table
+        //    borders as thin filled rectangles (common in spreadsheet exports).
+        //    Only runs when ALL other methods found nothing on this page.
+        if !page_tables.contains_key(&page) {
+            let page_rects: Vec<&crate::types::PdfRect> =
+                rects.iter().filter(|r| r.page == page).collect();
+            let mut synth_lines: Vec<crate::types::PdfLine> = Vec::new();
+            for r in &page_rects {
+                let (mut w, mut h) = (r.width, r.height);
+                let (mut x, mut y) = (r.x, r.y);
+                if w < 0.0 {
+                    x += w;
+                    w = -w;
+                }
+                if h < 0.0 {
+                    y += h;
+                    h = -h;
+                }
+                if h < 2.0 && w >= 10.0 {
+                    let mid_y = y + h / 2.0;
+                    synth_lines.push(crate::types::PdfLine {
+                        x1: x,
+                        y1: mid_y,
+                        x2: x + w,
+                        y2: mid_y,
+                        page,
+                    });
+                } else if w < 2.0 && h >= 10.0 {
+                    let mid_x = x + w / 2.0;
+                    synth_lines.push(crate::types::PdfLine {
+                        x1: mid_x,
+                        y1: y,
+                        x2: mid_x,
+                        y2: y + h,
+                        page,
+                    });
+                }
+            }
+            if synth_lines.len() >= 10 {
+                let page_text: Vec<TextItem> = text_items
+                    .iter()
+                    .filter(|i| i.page == page)
+                    .cloned()
+                    .collect();
+                let line_tables = detect_tables_from_lines(&page_text, &synth_lines, page);
+                for table in &line_tables {
+                    for &idx in &table.item_indices {
+                        table_items.insert(idx);
+                    }
+                    let table_y = table.rows.first().copied().unwrap_or(0.0);
+                    let table_md = table_to_markdown(table);
+                    page_tables
+                        .entry(page)
+                        .or_default()
+                        .push((table_y, table_md));
+                }
+            }
+        }
+
         // Merged-band retry: if we split into bands but found no tables in
         // any band, retry heuristic detection with all items as a single band.
         // This catches borderless tables whose text-column alignment was
@@ -915,7 +980,7 @@ pub(crate) fn to_markdown_from_items_with_rects_and_lines(
                 band_items.len(),
                 was_split
             );
-            let heuristic_tables = detect_tables(band_items, base_size, false);
+            let heuristic_tables = detect_tables(band_items, base_size, page_has_columns);
             for table in &heuristic_tables {
                 for &idx in &table.item_indices {
                     if let Some(&page_idx) = band_index_map.get(idx) {

src/python.rs

@@ -248,21 +248,34 @@ fn convert_text_items(items: Vec<crate::TextItem>) -> Vec<PyTextItem> {
         .collect()
 }
 
-fn parse_page_regions(page_regions: Vec<(u32, Vec<Vec<f64>>)>) -> Vec<(u32, Vec<[f32; 4]>)> {
+fn parse_page_regions(
+    page_regions: Vec<(u32, Vec<Vec<f64>>)>,
+) -> PyResult<Vec<(u32, Vec<[f32; 4]>)>> {
     page_regions
         .into_iter()
         .map(|(page, regions)| {
-            let bboxes: Vec<[f32; 4]> = regions
-                .iter()
-                .map(|r| {
-                    if r.len() != 4 {
-                        [0.0, 0.0, 0.0, 0.0]
-                    } else {
-                        [r[0] as f32, r[1] as f32, r[2] as f32, r[3] as f32]
-                    }
-                })
-                .collect();
-            (page, bboxes)
+            let mut bboxes: Vec<[f32; 4]> = Vec::with_capacity(regions.len());
+            for (idx, region) in regions.into_iter().enumerate() {
+                if region.len() != 4 {
+                    return Err(PyValueError::new_err(format!(
+                        "Invalid region at page {page}, index {idx}: expected [x1, y1, x2, y2], got {} values",
+                        region.len()
+                    )));
+                }
+                let [x1, y1, x2, y2] = [region[0], region[1], region[2], region[3]];
+                if !(x1.is_finite() && y1.is_finite() && x2.is_finite() && y2.is_finite()) {
+                    return Err(PyValueError::new_err(format!(
+                        "Invalid region at page {page}, index {idx}: coordinates must be finite numbers"
+                    )));
+                }
+                if x2 < x1 || y2 < y1 {
+                    return Err(PyValueError::new_err(format!(
+                        "Invalid region at page {page}, index {idx}: expected x2>=x1 and y2>=y1, got [{x1}, {y1}, {x2}, {y2}]"
+                    )));
+                }
+                bboxes.push([x1 as f32, y1 as f32, x2 as f32, y2 as f32]);
+            }
+            Ok((page, bboxes))
         })
         .collect()
 }
@@ -424,7 +437,7 @@ fn extract_text_in_regions_bytes(
     data: &[u8],
     page_regions: Vec<(u32, Vec<Vec<f64>>)>,
 ) -> PyResult<Vec<PyPageRegionTexts>> {
-    let regions = parse_page_regions(page_regions);
+    let regions = parse_page_regions(page_regions)?;
     let results = crate::extract_text_in_regions_mem(data, &regions).map_err(to_py_err)?;
     Ok(convert_region_results(results))
 }

src/tables/detect_heuristic.rs

@@ -219,7 +219,7 @@ pub fn detect_tables(items: &[TextItem], base_font_size: f32, skip_body_font: bo
             body_font_low,
             body_font_high,
         );
-        if body_candidates.len() >= 9 {
+        if body_candidates.len() >= 6 {
             let regions = find_table_regions_strict(&body_candidates);
             log::debug!("body-font: {} strict regions found", regions.len());
 
@@ -241,7 +241,7 @@ pub fn detect_tables(items: &[TextItem], base_font_size: f32, skip_body_font: bo
                     body_candidates.len()
                 );
 
-                if region_items.len() < 9 {
+                if region_items.len() < 6 {
                     continue;
                 }
 
@@ -801,7 +801,25 @@ fn has_table_like_content(cells: &[Vec<String>], mode: TableDetectionMode) -> bo
     // Bypass content check for wide tables (3+ columns) — text-only tables
     // (category lists, program descriptions) are legitimate if they passed
     // all structural validations (alignment, consistency, not key-value).
-    pct_data > min_pct || num_cols >= 3
+    // Also bypass for 2-column body-font tables with short cells (avg ≤40 chars),
+    // which are likely definition/category lists, not paragraph text.
+    if pct_data > min_pct || num_cols >= 3 {
+        return true;
+    }
+    if num_cols == 2 && matches!(mode, TableDetectionMode::BodyFont) {
+        let non_empty: Vec<usize> = cells
+            .iter()
+            .skip(1)
+            .flat_map(|row| row.iter())
+            .filter(|c| !c.trim().is_empty())
+            .map(|c| c.trim().len())
+            .collect();
+        if !non_empty.is_empty() {
+            let avg_len = non_empty.iter().sum::<usize>() / non_empty.len();
+            return avg_len <= 25;
+        }
+    }
+    false
 }
 
 /// Check if a cell value looks like table data

src/tables/detect_lines.rs

@@ -243,9 +243,11 @@ pub fn detect_tables_from_lines(items: &[TextItem], lines: &[PdfLine], page: u32
                 .map(|s| (s - mean_spacing).powi(2))
                 .sum::<f32>()
                 / spacings.len() as f32;
-            let cv = variance.sqrt() / mean_spacing; // coefficient of variation
-                                                     // CV < 0.05 means nearly identical spacing — chart grid
-            if cv < 0.05 {
+            let cv = variance.sqrt() / mean_spacing;
+            // CV < 0.02 means nearly identical spacing — likely chart grid.
+            // Spreadsheet-exported tables often have uniform rows (CV 0.03-0.05),
+            // so we use a tighter threshold to avoid false negatives.
+            if cv < 0.02 {
                 return Vec::new();
             }
         }

tests/integration_tests.rs

@@ -1232,6 +1232,55 @@ fn test_extract_regions_mem_not_a_pdf() {
     assert!(result.is_err(), "Non-PDF input should return an error");
 }
 
+#[test]
+fn test_extract_regions_mem_rotated_page_not_false_empty() {
+    let buf = std::fs::read("tests/fixtures/tnagriculture_06_12.pdf").unwrap();
+    let regions =
+        extract_text_in_regions_mem(&buf, &[(0, vec![[0.0, 0.0, 1200.0, 1200.0]])]).unwrap();
+    assert_eq!(regions.len(), 1);
+    assert_eq!(regions[0].regions.len(), 1);
+    let region = &regions[0].regions[0];
+    assert!(
+        !region.text.trim().is_empty(),
+        "Rotated page full-region extraction should not be empty"
+    );
+    assert!(
+        !region.needs_ocr,
+        "Rotated page with native text should not be flagged for OCR fallback"
+    );
+    assert!(
+        region
+            .text
+            .contains("DISTRICT WISE PRODUCTION OF SPICES AND CONDIMENTS"),
+        "Expected known title from rotated fixture in extracted region text"
+    );
+}
+
+#[test]
+fn test_collect_text_in_region_keeps_partial_overlap_items() {
+    let item = make_text_item("EdgeWord", 100.0, 700.0, 12.0, 1);
+    // Region intersects only the left edge of the item. Center x=124 falls
+    // outside x=[95,120], so center-only containment would drop it.
+    let text = pdf_inspector::collect_text_in_region(&[item], 95.0, 80.0, 120.0, 110.0, 800.0);
+    assert!(
+        text.contains("EdgeWord"),
+        "Partially overlapping items should be retained in region extraction"
+    );
+}
+
+#[test]
+fn test_collect_text_in_region_uses_rtl_sorting() {
+    let items = vec![
+        make_text_item("بكم", 240.0, 700.0, 12.0, 1),
+        make_text_item("مرحبا", 300.0, 700.0, 12.0, 1),
+    ];
+    let text = pdf_inspector::collect_text_in_region(&items, 0.0, 0.0, 600.0, 800.0, 800.0);
+    assert_eq!(
+        text, "مرحبا بكم",
+        "Region path should reuse RTL-aware line sorting"
+    );
+}
+
 // =========================================================================
 // Fast vs normal extraction comparison
 // =========================================================================

tests/snapshots/p1244-1996.md

@@ -8,7 +8,9 @@ Department of the Treasury **Internal Revenue Service**
 
 # and Report to Employer
 
-**This publication contains:** **Form 4070A, Employee’s Daily Record of** Tips **Form 4070, Employee’s Report of Tips to** Employer
+### This publication contains:
+
+**Form 4070A, Employee’s Daily Record of** Tips **Form 4070, Employee’s Report of Tips to** Employer
 
 For the period
 

tests/snapshots/real-estate-pricing.md

@@ -6,9 +6,7 @@
 
 8 4 Z E L L / L U R I E R E A L E S T A T E C E N T E R
 
-**Table I: Cap rate correlations**
-
-**Cap Rate Correlation With:*** **BBB Corp** **10-Year Bond Yield S&P Dividend** **Treasury (10-15 yr) Yield** Multifamily 0.187 0.771 0.068 Industrial-0.221 0.748-0.307 CBD Office-0.449 0.694-0.458 Retail-0.181 0.649-02.58
+**Table I: Cap rate correlations** **Cap Rate Correlation With:*** **BBB Corp** **10-Year Bond Yield S&P Dividend** **Treasury (10-15 yr) Yield** Multifamily 0.187 0.771 0.068 Industrial-0.221 0.748-0.307 CBD Office-0.449 0.694-0.458 Retail-0.181 0.649-02.58
 
 * Based on 25 years of data for the 10-yrT & S&P DivYld; and 14 years for BBB.
 **Figure 1:** NCREIF cap rates vs. 10-yearTreasury
@@ -34,9 +32,7 @@ R E V I E W 8 5
 
 1982 1986 1990 1994 1998 2002 2006
 
-**Table II: Correlationsofspreadsbypropertytype**
-
-**Correlation of Cap Rate Spreads Over Treasury** **Multifamily Industrial CBD Office**
+**Table II: Correlationsofspreadsbypropertytype** **Correlation of Cap Rate Spreads Over Treasury** **Multifamily Industrial CBD Office**
 
 ||Multifamily|Industrial|CBD Office|
 |---|---|---|---|

tests/snapshots/thermo-freon12.md

@@ -26,19 +26,16 @@ S = Entropy (kJ/kg.K)
 
 **Physical Properties**
 
-Chemical Formula CCl2F2
+|Chemical Formula|CCl2F2|
+|---|---|
+|Molecular mass|120.91|
+|Boiling Point At one atmosphere|-29.75°C|
+|Critical Temperature|111.97°C|
+|Critical Pressure|4136 kPa|
+|Critical Density|565.0 kg/m|
+|Critical Volume|0.0018 m|
 
-Molecular mass 120.91
-
-Boiling Point-29.75°C At one atmosphere
-
-Critical Temperature 111.97°C
-
-Critical Pressure 4136 kPa
-
-3 Critical Density 565.0 kg/m
-
-Critical Volume 0.0018 m /kg
+/kg
 
 l
 

tests/test_python.py

@@ -262,6 +262,13 @@ class TestExtractTextInRegions:
         assert results[0].page == 0
         assert results[1].page == 1
 
+    def test_malformed_region_raises_value_error(self):
+        with pytest.raises(ValueError, match="Invalid region"):
+            pdf_inspector.extract_text_in_regions(
+                fixture_path("thermo-freon12.pdf"),
+                [(0, [[0.0, 0.0, 600.0]])],
+            )
+
 
 # ---------------------------------------------------------------------------
 # Error handling