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+# PDF Layer Extractor - Summary
+
+## What It Does
+
+Extracts colored layers from PDF industrial diagrams into separate transparent PNG files.
+
+✓ Single PDF file processing
+✓ White background filtered (pure white only)
+✓ Variable number of layers (auto-detected)
+✓ Handles antialiasing around text
+✓ High-quality output at configurable DPI
+
+## Quick Start
+
+1. Install dependencies:
+```bash
+pip install -r requirements.txt
+```
+
+2. Run on your PDF:
+```bash
+python layer_extractor.py your_diagram.pdf
+```
+
+3. Find layers in `output/` folder
+
+## Key Features
+
+### Automatic Color Detection
+Uses K-means clustering to identify distinct colored layers. White (RGB ≥ 250) is treated as background only.
+
+### Antialiasing Handling
+The tolerance parameter (default 30) handles color mixing:
+- Text antialiasing creates gray pixels around black text
+- Tolerance value captures these gradual color transitions
+- Each pixel gets alpha based on distance from target color
+
+### Output Format
+Files named: `diagram_layerN_RRR_GGG_BBB.png`
+- Transparent PNG with only that color layer
+- RGB values in filename for reference
+
+## Common Usage
+
+```bash
+# Default (works for most diagrams)
+python layer_extractor.py diagram.pdf
+
+# High quality
+python layer_extractor.py diagram.pdf --dpi 600
+
+# Strict color separation (less antialiasing bleed)
+python layer_extractor.py diagram.pdf -t 20
+
+# Lenient (more antialiasing tolerance)
+python layer_extractor.py diagram.pdf -t 40
+
+# Extract top 3 layers only
+python layer_extractor.py diagram.pdf -n 3
+
+# Custom output folder
+python layer_extractor.py diagram.pdf -o my_layers/
+```
+
+## Parameters
+
+| Parameter | Default | Description |
+|-----------|---------|-------------|
+| `--dpi` | 300 | PDF rendering resolution (150/300/600) |
+| `-t, --tolerance` | 30 | Color matching tolerance (15-50 typical) |
+| `-n, --n-layers` | auto | Number of layers to extract |
+| `-m, --min-pixels` | 100 | Minimum pixels for valid layer |
+| `-o, --output` | output | Output directory |
+
+## Tolerance Guide
+
+The tolerance parameter is key to handling antialiasing:
+
+- **15-20**: Very strict, clean diagrams with no antialiasing
+- **30** (default): Balanced, handles moderate antialiasing
+- **40-50**: Lenient, for heavy antialiasing or compression artifacts
+
+### Example: Gray Layer with Black Text
+
+When you have a light gray layer with black text:
+- Black text creates gray antialiasing pixels
+- These gray pixels are close to the gray layer color
+- Higher tolerance includes them in the gray layer
+- Lower tolerance might miss them
+
+Start with default (30) and adjust ±10 based on results.
+
+## Files Included
+
+1. **layer_extractor.py** - Main script
+2. **requirements.txt** - Dependencies (PyMuPDF, Pillow, numpy, scikit-learn)
+3. **README.md** - Full documentation
+4. **QUICKSTART.md** - Quick reference guide
+
+## Technical Notes
+
+- Uses PyMuPDF to render PDF at specified DPI
+- K-means clustering identifies dominant colors
+- Euclidean distance in RGB space for color matching
+- Alpha channel gradient for smooth edges
+- White detection: all RGB values ≥ 250
+
+## Example Output
+
+Input: `piping_diagram.pdf`
+Output:
+```
+output/
+├── piping_diagram_layer1_220_050_050.png  (red piping)
+├── piping_diagram_layer2_050_100_220.png  (blue electrical)
+├── piping_diagram_layer3_150_150_150.png  (gray annotations)
+└── piping_diagram_layer4_050_180_050.png  (green mechanical)
+```
+
+Each PNG has transparent background with only that color layer visible.