first commit

+.idea/
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+# PDF转图片脚本
+
+## 主要处理逻辑
+- 提取PDF页面中的图片对象
+  - 图片对象数目为0(如电子账单)，保存整个页面为png图片
+  - 图片对象数目为1
+    - 大图，保存图片对象
+    - 小图(如电子账单盖章)，保存整个页面为png图片
+  - 图片对象数目大于1
+    - 多大图，保存图片对象
+    - 多碎图，根据宽高突变位置分组，拼接合并后保存
+  - 其他特殊情况：保存整个页面为png图片
+  
+ ## 用法
+ - python3.6+
+ - `pip install -r requirements`
+ - `python pdf_to_img.py pdf_path [img_path]`
+ 
+    |  参数   | 是否必须 | 说明 | 缺省值 |
+    |  ----  | ----  | ----  | ----  |
+    | pdf_path  | 是 | PDF文件或目录路径  | - |
+    | img_path  | 否 | 图片保存路径  | PDF文件路径 |
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+import os
+import sys
+import fitz
+from PIL import Image
+from io import BytesIO
+
+if sys.version_info[0] < 3:
+    raise Exception("This program requires at least python3.6")
+if len(sys.argv) < 2:
+    print('用法：python pdf_to_img.py PDF文件或目录路径 [图片保存路径]')
+    sys.exit(0)
+if not os.path.exists(sys.argv[1]):
+    print('PDF文件或目录不存在: {0}'.format(sys.argv[1]))
+    sys.exit(0)
+
+LOG_BASE = '[pdf to img]'
+
+# 页面保存为png图片参数
+ZOOM_X = ZOOM_Y = 2.0
+trans = fitz.Matrix(ZOOM_X, ZOOM_X).preRotate(0)  # zoom factor 2 in each dimension
+
+# 特殊filter处理
+ADOBE_FILTER_SET = {'FlateDecode', 'JPXDecode', 'JBIG2Decode'}
+
+# 宽高阈值组合
+WH_COUPLE_1 = (500, 500)
+WH_COUPLE_2 = (700, 647)
+WH_COUPLE_3 = (100, 100)
+WH_COUPLE_4 = (100, 300)
+WH_COUPLE_5 = (100, 200)
+
+
+class PDFHandler:
+
+    def __init__(self, path, target_path):
+        self.path = path
+        self.img_dir_path = os.path.join(target_path, os.path.splitext(os.path.basename(path))[0])
+        self.xref_set = set()
+
+    def get_img_save_path(self, pno, img_index=0, ext='png'):
+        return os.path.join(self.img_dir_path, 'page_{0}_img_{1}.{2}'.format(pno, img_index, ext))
+
+    def page_to_png(self, page):
+        pm = page.getPixmap(matrix=trans, alpha=False)
+        img_save_path = self.get_img_save_path(page.number)
+        pm.writePNG(img_save_path)
+
+    @staticmethod
+    def getimage(pix):
+        # RGB
+        if pix.colorspace.n != 4:
+            return pix
+        # GRAY/CMYK
+        tpix = fitz.Pixmap(fitz.csRGB, pix)
+        return tpix
+
+    def recover_pix(self, doc, xref, smask, colorspace):
+        if smask != 0:
+            # we need to reconstruct the alpha channel with the smask
+            pix1 = fitz.Pixmap(doc, xref)
+            pix2 = fitz.Pixmap(doc, smask)  # create pixmap of the /SMask entry
+
+            # sanity check
+            if not (pix1.irect == pix2.irect and pix1.alpha == pix2.alpha == 0 and pix2.n == 1):
+                pix2 = None
+                return self.getimage(pix1)
+
+            pix = fitz.Pixmap(pix1)  # copy of pix1, alpha channel added
+            pix.setAlpha(pix2.samples)  # treat pix2.samples as alpha value
+            pix1 = pix2 = None  # free temp pixmaps
+            return self.getimage(pix)
+        elif colorspace in {'Separation', 'DeviceCMYK'}:
+            pix = fitz.Pixmap(doc, xref)
+            tpix = fitz.Pixmap(fitz.csRGB, pix)
+            return tpix
+        else:
+            return doc.extractImage(xref)
+
+    @staticmethod
+    def get_img_data(pix):
+        if type(pix) is dict:  # we got a raw image
+            ext = pix["ext"]
+            img_data = pix["image"]
+        else:  # we got a pixmap
+            ext = 'png'
+            img_data = pix.getPNGData()
+        return ext, img_data
+
+    def extract_single_image(self, pdf, xref, smask, colorspace, pno, img_index=0):
+        pix = self.recover_pix(pdf, xref, smask, colorspace)
+        ext, img_data = self.get_img_data(pix)
+        img_save_path = self.get_img_save_path(pno, img_index=img_index, ext=ext)
+        with open(img_save_path, "wb") as f:
+            f.write(img_data)
+        self.xref_set.add(xref)
+
+    @staticmethod
+    def split_il(il):
+        broken_il = []
+        start = 0
+        length = len(il)
+        page_to_png = None
+        for i in range(length):
+            # 当图片对象含有特殊filter时，特殊处理：整个页面保存为png图片
+            if il[i][-1] in ADOBE_FILTER_SET:
+                page_to_png = True
+                break
+        else:
+            for i in range(length):
+                # 当图片对象够大时，不作碎图合并处理，而是单纯提取
+                if il[i][2] >= WH_COUPLE_2[0] and il[i][3] >= WH_COUPLE_2[1]:
+                    break
+                if i == start:
+                    if i == length - 1:
+                        broken_il.append(il[start: length])
+                    continue
+                elif i == length - 1:
+                    if il[i][2] == il[i - 1][2]:
+                        broken_il.append(il[start: length])
+                    else:
+                        broken_il.append(il[start: i])
+                        broken_il.append(il[i: length])
+                    continue
+                if il[i][2] != il[i - 1][2]:
+                    broken_il.append(il[start: i])
+                    start = i
+                elif il[i][3] != il[i - 1][3]:
+                    broken_il.append(il[start: i + 1])
+                    start = i + 1
+            else:
+                # 碎图分组结果
+                return broken_il
+        return page_to_png
+
+    def merge_il(self, pdf, pno, il):
+        # 尝试碎图合并前的分组
+        il.sort(key=lambda x: x[0])
+        broken_il = self.split_il(il)
+        print('broken_il: {0}'.format(broken_il))
+
+        page_to_png = True
+        # 3.1 当图片对象够大时，不作碎图合并处理，而是单纯提取
+        if broken_il is None:
+            page_to_png = False
+            for img_index, img in enumerate(il):
+                xref, smask, width, height, _, colorspace, _, _, adobe_filter = img
+                if width < WH_COUPLE_3[0] or height < WH_COUPLE_3[1]:  # 过滤小图(如二维码)
+                    continue
+                elif xref not in self.xref_set:
+                    self.extract_single_image(pdf, xref, smask, colorspace, pno, img_index)
+        # 3.2 碎图按照分组合并
+        elif isinstance(broken_il, list) and len(broken_il) <= 2:
+            for img_index, img_il in enumerate(broken_il):
+                # 3.2.1 仅一张碎图，过滤或直接提取
+                if len(img_il) == 1:
+                    xref, smask, width, height, _, colorspace, _, _, adobe_filter = img_il[0]
+                    # 过滤小图(如二维码)
+                    if width < WH_COUPLE_4[0] or height < WH_COUPLE_4[1] or \
+                            (width < WH_COUPLE_1[0] and height < WH_COUPLE_1[1]):
+                        continue
+                    elif xref not in self.xref_set:
+                        self.extract_single_image(pdf, xref, smask, colorspace, pno, img_index)
+                        page_to_png = False
+                # 3.2.2 多张碎图，竖向拼接
+                else:
+                    height_sum = sum([img[3] for img in img_il])
+                    width = img_il[0][2]
+                    # 过滤小图和不常规大图
+                    if width < WH_COUPLE_5[0] or height_sum < WH_COUPLE_5[1] or \
+                            (width > 1000 and height_sum > width * 3):
+                        continue
+                    im_list = []
+                    for img in img_il:
+                        xref, smask, _, height, _, colorspace, _, _, adobe_filter = img
+                        pix = self.recover_pix(pdf, xref, smask, colorspace)
+                        ext, img_data = self.get_img_data(pix)
+                        im = Image.open(BytesIO(img_data))
+                        im_list.append((height, im, ext))
+                    new_img = Image.new(im_list[0][1].mode, (width, height_sum))
+                    h_now = 0
+                    for h, m, _ in im_list:
+                        new_img.paste(m, box=(0, h_now))
+                        h_now += h
+                    img_save_path = self.get_img_save_path(pno, img_index, im_list[0][2])
+                    new_img.save(img_save_path)
+                    page_to_png = False
+
+        # 3.3 碎图分组大于2、全过滤、含特殊filter，特殊处理：整个页面保存为png图片
+        if page_to_png:
+            page = pdf.loadPage(pno)
+            self.page_to_png(page)
+
+    def extract_image(self):
+        os.makedirs(self.img_dir_path, exist_ok=True)
+        with fitz.Document(self.path) as pdf:
+            print('++++++++++' * 5)
+            print('{0} [start] [pdf_path={1}] [metadata={2}]'.format(LOG_BASE, self.path, pdf.metadata))
+            for pno in range(pdf.pageCount):
+                il = pdf.getPageImageList(pno)  # 获取页面图片对象
+                # (xref, smask, width, height, bpc, colorspace, alt.colorspace, name, filter, invoker)
+                print('---------- page: {0} ----------'.format(pno))
+                print('img_object_list: {0}'.format(il))
+
+                # 单纯提取页面图片对象
+                # for img_index, img in enumerate(il):
+                #     pix = self.recover_pix(pdf, img[0], img[1], img[5])
+                #     ext, img_data = self.get_img_data(pix)
+                #     img_save_path = self.get_img_save_path(pno, img_index, ext)
+                #     with open(img_save_path, "wb") as f:
+                #         f.write(img_data)
+
+                # 1.页面图片对象数目为0时，保存整个页面为png图片
+                if len(il) == 0:
+                    page = pdf.loadPage(pno)
+                    self.page_to_png(page)
+                # 2.页面图片对象数目为1时：
+                # 小图(如电子账单的盖章)：保存整个页面为png图片
+                # 大图：提取图片对象
+                elif len(il) == 1:
+                    xref, smask, width, height, _, colorspace, _, _, _ = il[0]
+                    # 小图
+                    if width < WH_COUPLE_1[0] and height < WH_COUPLE_1[1]:
+                        page = pdf.loadPage(pno)
+                        self.page_to_png(page)
+                    # 大图
+                    elif xref not in self.xref_set:
+                        self.extract_single_image(pdf, xref, smask, colorspace, pno)
+                # 3.页面图片对象数目大于1时，特殊处理
+                else:
+                    self.merge_il(pdf, pno, il)
+
+
+def extract_image(pdf_path, target_path):
+    pdf_handler = PDFHandler(pdf_path, target_path)
+    pdf_handler.extract_image()
+
+
+def main():
+    pdf_path = os.path.realpath(sys.argv[1])
+    # 目录：遍历处理所有pdf文件
+    if os.path.isdir(pdf_path):
+        completed_count = 0
+        failed_list = []
+        for parent, dirnames, filenames in os.walk(pdf_path):
+            # 图片保存目录
+            target_path = os.path.realpath(sys.argv[2]) if len(sys.argv) > 2 else parent
+            for pdf_file in filenames:
+                if not pdf_file.endswith('pdf') and not pdf_file.endswith('PDF'):
+                    continue
+                pdf_file_path = os.path.join(parent, pdf_file)
+                try:
+                    extract_image(pdf_file_path, target_path)
+                except Exception as e:
+                    print('{0} [failed] [err={1}] [pdf_path={2}]'.format(LOG_BASE, e, pdf_file_path))
+                    failed_list.append(pdf_file_path)
+                else:
+                    print('{0} [completed] [pdf_path={1}]'.format(LOG_BASE, pdf_path))
+                    completed_count += 1
+        print('{0} [all completed] [completed_count={1}] [failed_count={2}] [failed_pdf_path={3}]'.format(
+            LOG_BASE, completed_count, len(failed_list), failed_list))
+    # 文件：处理pdf文件
+    else:
+        # 图片保存目录
+        target_path = os.path.realpath(sys.argv[2]) if len(sys.argv) > 2 else os.path.dirname(pdf_path)
+        try:
+            extract_image(pdf_path, target_path)
+        except Exception as e:
+            print('{0} [failed] [err={1}] [pdf_path={2}]'.format(LOG_BASE, e, pdf_path))
+        else:
+            print('{0} [completed] [pdf_path={1}]'.format(LOG_BASE, pdf_path))
+
+
+if __name__ == "__main__":
+    main()

+Pillow==7.2.0
+PyMuPDF==1.17.0
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