Langchain-Chatchat/libs/chatchat-server/chatchat/server/file_rag/document_loaders/mypdfloader.py

from typing import List

import cv2
import numpy as np
import tqdm
from langchain_community.document_loaders.unstructured import UnstructuredFileLoader
from PIL import Image
import re
from chatchat.settings import Settings
from chatchat.server.file_rag.document_loaders.ocr import get_ocr
from chatchat.utils import build_logger

logger = build_logger()

class RapidOCRPDFLoader(UnstructuredFileLoader):
    def _get_elements(self) -> List:
        def rotate_img(img, angle):
            """
            img   --image
            angle --rotation angle
            return--rotated img
            """

            h, w = img.shape[:2]
            rotate_center = (w / 2, h / 2)
            # 获取旋转矩阵
            # 参数1为旋转中心点;
            # 参数2为旋转角度,正值-逆时针旋转;负值-顺时针旋转
            # 参数3为各向同性的比例因子,1.0原图，2.0变成原来的2倍，0.5变成原来的0.5倍
            M = cv2.getRotationMatrix2D(rotate_center, angle, 1.0)
            # 计算图像新边界
            new_w = int(h * np.abs(M[0, 1]) + w * np.abs(M[0, 0]))
            new_h = int(h * np.abs(M[0, 0]) + w * np.abs(M[0, 1]))
            # 调整旋转矩阵以考虑平移
            M[0, 2] += (new_w - w) / 2
            M[1, 2] += (new_h - h) / 2

            rotated_img = cv2.warpAffine(img, M, (new_w, new_h))
            return rotated_img

        def pdf2text(filepath):
            import fitz  # pyMuPDF里面的fitz包，不要与pip install fitz混淆
            import numpy as np

            ocr = get_ocr()
            doc = fitz.open(filepath)
            resp = ""

            b_unit = tqdm.tqdm(
                total=doc.page_count, desc="RapidOCRPDFLoader context page index: 0"
            )
            for i, page in enumerate(doc):
                b_unit.set_description(
                    "RapidOCRPDFLoader context page index: {}".format(i)
                )
                b_unit.refresh()
                text = page.get_text("")
                # resp += text + "\n"
                text_lines = text.strip().split("\n")
                logger.info(f"****page:{i+1}****，文字内容：{text_lines}")
                img_list = page.get_image_info(xrefs=True)
                ocr_result = []
                for img in img_list:
                    if xref := img.get("xref"):
                        bbox = img["bbox"]
                        # 检查图片尺寸是否超过设定的阈值
                        if (bbox[2] - bbox[0]) / (page.rect.width) < Settings.kb_settings.PDF_OCR_THRESHOLD[
                            0
                        ] or (bbox[3] - bbox[1]) / (
                            page.rect.height
                        ) < Settings.kb_settings.PDF_OCR_THRESHOLD[1]:
                            continue
                        pix = fitz.Pixmap(doc, xref)
                        samples = pix.samples
                        if int(page.rotation) != 0:  # 如果Page有旋转角度，则旋转图片
                            img_array = np.frombuffer(
                                pix.samples, dtype=np.uint8
                            ).reshape(pix.height, pix.width, -1)
                            tmp_img = Image.fromarray(img_array)
                            ori_img = cv2.cvtColor(np.array(tmp_img), cv2.COLOR_RGB2BGR)
                            rot_img = rotate_img(img=ori_img, angle=360 - page.rotation)
                            img_array = cv2.cvtColor(rot_img, cv2.COLOR_RGB2BGR)
                        else:
                            img_array = np.frombuffer(
                                pix.samples, dtype=np.uint8
                            ).reshape(pix.height, pix.width, -1)

                        result, _ = ocr(img_array)
                        if result:
                            ocr_result = [line[1] for line in result]
                            resp += "\n".join(ocr_result)

                if (len(ocr_result)>0):
                    resp += "\n".join(ocr_result)
                else:
                    if text_lines:
                    # 假设页码在最后一行
                        if text_lines[-1].isdigit():
                            text = "\n".join(text_lines[:-1])
                            print(f"******去除了页码")
                    resp += text + "\n"
                # 更新进度
                b_unit.update(1)
            resp = re.sub(r'((?<!.)\d+(?!\.|[a-zA-Z0-9]))', r"\1 ", resp)
            resp = re.sub(r'((?<!.)[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+(?!\.|[a-zA-Z0-9]))', r"\1 ", resp)
            resp = re.sub(r'((?<!.)[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+(?!\.|[a-zA-Z0-9]))', r"\1 ", resp)
            return resp

        text = pdf2text(self.file_path)
        from unstructured.partition.text import partition_text

        return partition_text(text=text, **self.unstructured_kwargs)


if __name__ == "__main__":
    loader = RapidOCRPDFLoader(file_path="/Users/tonysong/Desktop/test.pdf")
    docs = loader.load()
    print(docs)