#!/usr/bin/env python3 # -*- coding: utf-8 -*- """ PDF去水印工具 将PDF转换为图片，去除水印后再转回PDF """ from pathlib import Path from typing import List, Optional import tempfile import shutil try: from PIL import Image PIL_AVAILABLE = True except ImportError: PIL_AVAILABLE = False def _pdf_to_pil_images(input_pdf: str, dpi: int = 200) -> Optional[List["Image.Image"]]: """ 将 PDF 转为 PIL 图片列表。优先 pdf2image（需 poppler），失败时用 pypdfium2（无需 poppler）。 """ # 1) 尝试 pdf2image（需系统安装 poppler-utils） try: from pdf2image import convert_from_path return convert_from_path(input_pdf, dpi=dpi) except Exception as e: err_msg = str(e).lower() if "pdfinfo" in err_msg or "poppler" in err_msg or "no such file" in err_msg: pass # 无 poppler，尝试 pypdfium2 else: raise # 2) 备用：pypdfium2（无需 poppler） try: import pypdfium2 as pdfium pdf = pdfium.PdfDocument(input_pdf) try: scale = dpi / 72.0 images = [] for i in range(len(pdf)): page = pdf[i] bitmap = page.render(scale=scale) try: pil_image = bitmap.to_pil() images.append(pil_image) finally: bitmap.close() return images finally: try: pdf.close() except Exception: pass except ImportError: raise FileNotFoundError( "PDF 转图片需要 pdf2image+poppler 或 pypdfium2。" " 安装其一：apt install poppler-utils 或 pip install pypdfium2" ) def remove_watermark_from_pdf( input_pdf: str, output_pdf: str, light_threshold: int = 200, saturation_threshold: int = 30, dpi: int = 200 ) -> bool: """ 对PDF文件进行去水印处理 处理流程： 1. 将PDF的每一页转换为图片 2. 对每张图片进行去水印处理 3. 将处理后的图片合并为新的PDF Args: input_pdf: 输入PDF文件路径 output_pdf: 输出PDF文件路径 light_threshold: 水印亮度阈值（0-255），高于此值的浅色像素可能是水印 saturation_threshold: 水印饱和度阈值（0-255），低于此值的低饱和度像素可能是水印 dpi: PDF转图片的DPI，影响图片质量和处理速度 Returns: bool: 是否成功 """ try: from PIL import Image from utils.image_preprocessor import remove_watermark, check_opencv_available if not check_opencv_available(): print("⚠ OpenCV 未安装，无法进行去水印处理") return False temp_dir = tempfile.mkdtemp(prefix="pdf_watermark_") temp_path = Path(temp_dir) try: print(f"正在将PDF转换为图片（DPI={dpi}）...") images = _pdf_to_pil_images(input_pdf, dpi=dpi) if not images: print("⚠ 未得到任何页面图片") return False print(f"✓ 转换完成，共 {len(images)} 页") # 处理每一页 processed_images = [] for i, image in enumerate(images, 1): print(f"处理第 {i}/{len(images)} 页...", end='\r') # 保存原始图片 original_path = temp_path / f"page_{i}_original.png" image.save(str(original_path), "PNG") # 去水印 nowm_path = temp_path / f"page_{i}_nowm.png" processed_path = remove_watermark( str(original_path), output_path=str(nowm_path), light_threshold=light_threshold, saturation_threshold=saturation_threshold, method="hsv" ) # 加载处理后的图片 processed_img = Image.open(processed_path) processed_images.append(processed_img) print(f"\n✓ 所有页面处理完成") # 将图片合并为PDF print("正在生成PDF...") if processed_images: # 第一张图片作为主图片 first_image = processed_images[0] # 其余图片作为附加页 other_images = processed_images[1:] if len(processed_images) > 1 else [] # 保存为PDF first_image.save( output_pdf, "PDF", resolution=dpi, save_all=True, append_images=other_images ) print(f"✓ PDF生成完成: {output_pdf}") return True else: print("⚠ 没有处理任何图片") return False finally: # 清理临时目录 try: shutil.rmtree(temp_dir) except Exception as e: print(f"⚠ 清理临时目录失败: {e}") except ImportError as e: print(f"⚠ 缺少必要的库: {e}") print("请安装: pip install pypdfium2 或 pdf2image pillow PyPDF2 opencv-python；pdf2image 需系统安装 poppler-utils") return False except FileNotFoundError as e: print(f"⚠ {e}") return False except Exception as e: print(f"⚠ 去水印处理失败: {e}") import traceback traceback.print_exc() return False def crop_header_footer_from_pdf( input_pdf: str, output_pdf: str, header_ratio: float = 0.05, footer_ratio: float = 0.05, auto_detect: bool = False, dpi: int = 200 ) -> bool: """ 对 PDF 文件进行页眉页脚裁剪处理。 处理流程： 1. 将 PDF 的每一页转换为图片 2. 对每张图片进行页眉页脚裁剪 3. 将处理后的图片合并为新的 PDF Args: input_pdf: 输入 PDF 文件路径 output_pdf: 输出 PDF 文件路径 header_ratio: 页眉裁剪比例（0-1），默认 0.05 表示裁剪顶部 5% footer_ratio: 页脚裁剪比例（0-1），默认 0.05 表示裁剪底部 5% auto_detect: 是否自动检测页眉页脚边界 dpi: PDF 转图片的 DPI Returns: bool: 是否成功 """ try: from PIL import Image from utils.image_preprocessor import crop_header_footer, check_opencv_available if not check_opencv_available(): print("⚠ OpenCV 未安装，无法进行页眉页脚裁剪") return False temp_dir = tempfile.mkdtemp(prefix="pdf_crop_hf_") temp_path = Path(temp_dir) try: print(f"正在将 PDF 转换为图片（DPI={dpi}）...") images = _pdf_to_pil_images(input_pdf, dpi=dpi) if not images: print("⚠ 未得到任何页面图片") return False print(f"✓ 转换完成，共 {len(images)} 页") processed_images = [] for i, image in enumerate(images, 1): print(f"处理第 {i}/{len(images)} 页...", end="\r") original_path = temp_path / f"page_{i}_original.png" image.save(str(original_path), "PNG") cropped_path = temp_path / f"page_{i}_cropped.png" crop_header_footer( str(original_path), output_path=str(cropped_path), header_ratio=header_ratio, footer_ratio=footer_ratio, auto_detect=auto_detect, ) processed_img = Image.open(cropped_path) processed_images.append(processed_img) print("\n✓ 所有页面处理完成") print("正在生成 PDF...") if processed_images: first_image = processed_images[0] other_images = processed_images[1:] if len(processed_images) > 1 else [] first_image.save( output_pdf, "PDF", resolution=dpi, save_all=True, append_images=other_images, ) print(f"✓ PDF 生成完成: {output_pdf}") return True else: print("⚠ 没有处理任何图片") return False finally: try: shutil.rmtree(temp_dir) except Exception as e: print(f"⚠ 清理临时目录失败: {e}") except ImportError as e: print(f"⚠ 缺少必要的库: {e}") print("请安装: pip install pypdfium2 或 pdf2image pillow opencv-python；pdf2image 需系统安装 poppler-utils") return False except FileNotFoundError as e: print(f"⚠ {e}") return False except Exception as e: print(f"⚠ 页眉页脚裁剪失败: {e}") import traceback traceback.print_exc() return False