python2
1. 安装 
PyMuPDF==1.16.6
2. 
import fitz
def _pdf_to_image(self, pdf_path, file_data, image_dir):
    # 打开pdf
    with open(pdf_path, 'w') as f:
        f.write(file_data)
        pdf_obj = fitz.open(pdf_path)
    # 图片地址
    image_paths = []
    for page_index in range(pdf_obj.pageCount):
        image_path = os.path.join(image_dir, '{}.png'.format(page_index + 1))
        page = pdf_obj[page_index]
        # 595*842 默认也就是基数1 需求2480*3508 （像素）
        mat = fitz.Matrix(4.16806723, 4.16627078).preRotate(0)
        pix = page.getPixmap(matrix=mat, alpha=False)
        # 创建图片
        pix.writePNG(image_path)
        image_paths.append(image_path)
     return image_paths