Add method pdf2img(pdf_file, img_dir) for pdf convert to jpg

"""
parameter:
    pdf_file : the pdf file for convert 
    img_dir : the dir to save images

return:    
    pic_list: image list for pdf file
"""

tools/pdf2img.py

+# -*- coding: utf-8 -*-
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+"""
+1、安装库 pip install pymupdf
+2、安装库 pip install pillow
+3、直接运行
+"""
+import os
+import fitz
+
+import os
+import sys
+
+__dir__ = os.path.dirname(os.path.abspath(__file__))
+sys.path.append(__dir__)
+sys.path.append(os.path.abspath(os.path.join(__dir__, '..')))
+
+from ppocr.utils.logging import get_logger
+
+logger = get_logger()
+
+"""
+parameter:
+    pdf_file : the pdf file for convert 
+    img_dir : the dir to save images
+
+return:    
+    pic_list: image list for pdf file
+"""
+
+
+def pdf2img(pdf_file, img_dir):
+    doc = fitz.open(pdf_file)
+    pdf_name = os.path.splitext(pdf_file)[0]
+    pic_list = []
+    for pg in range(doc.pageCount):
+        page = doc[pg]
+        rotate = int(0)
+        # 每个尺寸的缩放系数为2，这将为我们生成分辨率提高四倍的图像。
+        zoom_x = 2.0
+        zoom_y = 2.0
+        trans = fitz.Matrix(zoom_x, zoom_y).prerotate(rotate)
+        pm = page.get_pixmap(matrix=trans, alpha=False)
+        # 注意下边的一行，这是本的重点。原文是生成的PNG，我给改成了JPG
+        if not os.path.exists(img_dir):
+            os.mkdir(img_dir)
+            logger.info('%s directory are created' % img_dir)
+        pm.pil_save('%s/%s.jpg' % (img_dir, pg), quality=1)
+        pic_list.append('%s/%s.jpg' % (img_dir, pg))
+    logger.info('%s pdf file are saved under %s successfully' % (pdf_file, img_dir))
+    return pic_list