如何用Python for NLP处理含有小字体文本的PDF文件？

pip install PyPDF2pip install pdfminer.six

import PyPDF2from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreterfrom pdfminer.pdfpage import PDFPagefrom pdfminer.converter import TextConverterfrom pdfminer.layout import LAParamsfrom io import StringIOdef extract_text_from_pdf(file_path):    text = ''    with open(file_path, 'rb') as file:        pdf_reader = PyPDF2.PdfReader(file)        for page_num in range(len(pdf_reader.pages)):            page_obj = pdf_reader.pages[page_num]            page_text = page_obj.extract_text()            text += page_text    return textdef extract_text_from_pdf_with_pdfminer(file_path):    text = ''    rsrcmgr = PDFResourceManager()    sio = StringIO()    codec = 'utf-8'    laparams = LAParams()    laparams.all_texts = True    converter = TextConverter(rsrcmgr, sio, codec=codec, laparams=laparams)    interpreter = PDFPageInterpreter(rsrcmgr, converter)    with open(file_path, 'rb') as file:        for page in PDFPage.get_pages(file):            interpreter.process_page(page)        text = sio.getvalue()    converter.close()    sio.close()    return text# 测试代码pdf_file = '小字体文本.pdf'extracted_text = extract_text_from_pdf(pdf_file)print(extracted_text)extracted_text_with_pdfminer = extract_text_from_pdf_with_pdfminer(pdf_file)print(extracted_text_with_pdfminer)