feat: MD 파일 병합 및 이미지 경로 통합 스크립트 추가 (#1)

- merge_markdown.py: 96개 페이지별 MD를 단일 파일로 병합
  - 이미지를 output/images/ 폴더로 통합, p{NN}_ prefix로 파일명 충돌 방지
  - file_range 파라미터로 부분 테스트 가능
- docs/tutorial.md: merge 명령어 및 사용법 문서화
- docs/history: 작업 이력 파일 추가

소요 시간: 10분 | Context: input 18k / output 2k tokens

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

extract_images.py

@@ -0,0 +1,175 @@
+#!/usr/bin/env python3
+"""
+Extract embedded images from PDF files
+"""
+
+import os
+import glob
+from pathlib import Path
+
+def extract_images_pypdfium2(pdf_path: str, output_dir: str = "output"):
+    """
+    Extract images using pypdfium2
+    """
+    try:
+        import pypdfium2 as pdfium
+        from PIL import Image
+        import io
+
+        pdf_file = Path(pdf_path)
+        base_name = pdf_file.stem
+        images_dir = os.path.join(output_dir, f"{base_name}_extracted_images")
+        os.makedirs(images_dir, exist_ok=True)
+
+        print(f"\nExtracting images from {pdf_file.name}...")
+
+        pdf = pdfium.PdfDocument(pdf_path)
+        image_count = 0
+
+        for page_num in range(len(pdf)):
+            page = pdf[page_num]
+
+            # Get images from page
+            for obj_index, obj in enumerate(page.get_objects()):
+                if obj.type == pdfium.FPDF_PAGEOBJ_IMAGE:
+                    try:
+                        # Extract image
+                        bitmap = obj.get_bitmap()
+                        pil_image = bitmap.to_pil()
+
+                        # Skip very small images (likely noise or artifacts)
+                        if pil_image.width < 50 or pil_image.height < 50:
+                            continue
+
+                        image_count += 1
+                        img_filename = f"page_{page_num + 1}_img_{obj_index + 1}.png"
+                        img_path = os.path.join(images_dir, img_filename)
+                        pil_image.save(img_path)
+                        print(f"  Saved: {img_filename} ({pil_image.width}x{pil_image.height})")
+
+                    except Exception as e:
+                        print(f"  Warning: Could not extract image {obj_index} from page {page_num + 1}: {e}")
+
+        pdf.close()
+
+        if image_count > 0:
+            print(f"  OK Total {image_count} images extracted to: {images_dir}")
+            return True
+        else:
+            print(f"  INFO: No images found in {pdf_file.name}")
+            return True
+
+    except Exception as e:
+        print(f"  ERROR: Failed with pypdfium2: {e}")
+        return False
+
+
+def extract_images_pymupdf(pdf_path: str, output_dir: str = "output"):
+    """
+    Extract images using PyMuPDF (fitz) - fallback method
+    """
+    try:
+        import fitz  # PyMuPDF
+
+        pdf_file = Path(pdf_path)
+        base_name = pdf_file.stem
+        images_dir = os.path.join(output_dir, f"{base_name}_extracted_images")
+        os.makedirs(images_dir, exist_ok=True)
+
+        print(f"\nExtracting images from {pdf_file.name} using PyMuPDF...")
+
+        doc = fitz.open(pdf_path)
+        image_count = 0
+
+        for page_num in range(len(doc)):
+            page = doc[page_num]
+            image_list = page.get_images(full=True)
+
+            for img_index, img_info in enumerate(image_list):
+                xref = img_info[0]
+
+                try:
+                    # Extract image
+                    base_image = doc.extract_image(xref)
+                    image_bytes = base_image["image"]
+                    image_ext = base_image["ext"]
+
+                    # Skip very small images
+                    if len(image_bytes) < 1000:  # Less than 1KB
+                        continue
+
+                    image_count += 1
+                    img_filename = f"page_{page_num + 1}_img_{img_index + 1}.{image_ext}"
+                    img_path = os.path.join(images_dir, img_filename)
+
+                    with open(img_path, "wb") as f:
+                        f.write(image_bytes)
+
+                    print(f"  Saved: {img_filename} ({len(image_bytes)} bytes)")
+
+                except Exception as e:
+                    print(f"  Warning: Could not extract image {img_index} from page {page_num + 1}: {e}")
+
+        doc.close()
+
+        if image_count > 0:
+            print(f"  OK Total {image_count} images extracted to: {images_dir}")
+            return True
+        else:
+            print(f"  INFO: No images found in {pdf_file.name}")
+            return True
+
+    except ImportError:
+        print("  ERROR: PyMuPDF not installed. Install with: pip install PyMuPDF")
+        return False
+    except Exception as e:
+        print(f"  ERROR: Failed with PyMuPDF: {e}")
+        return False
+
+
+def extract_images_from_pdf(pdf_path: str, output_dir: str = "output"):
+    """
+    Try to extract images using available methods
+    """
+    # Try pypdfium2 first (already installed)
+    success = extract_images_pypdfium2(pdf_path, output_dir)
+
+    if not success:
+        print("\nTrying PyMuPDF as fallback...")
+        success = extract_images_pymupdf(pdf_path, output_dir)
+
+    return success
+
+
+def extract_all_images(input_dir: str = "input", output_dir: str = "output"):
+    """
+    Extract images from all PDF files in the input directory
+    """
+    pdf_pattern = os.path.join(input_dir, "*.pdf")
+    pdf_files = sorted(glob.glob(pdf_pattern))
+
+    if not pdf_files:
+        print(f"No PDF files found in {input_dir}")
+        return
+
+    print(f"Found {len(pdf_files)} PDF files")
+    print("=" * 60)
+
+    successful = 0
+    failed = 0
+
+    for pdf_file in pdf_files:
+        if extract_images_from_pdf(pdf_file, output_dir):
+            successful += 1
+        else:
+            failed += 1
+
+    print("\n" + "=" * 60)
+    print(f"Image extraction complete!")
+    print(f"  Successful: {successful}")
+    print(f"  Failed: {failed}")
+    print(f"  Total: {len(pdf_files)}")
+
+
+if __name__ == "__main__":
+    extract_all_images()