如何从 PDF 中提取字体名称和大小#
How to extract font names and sizes from PDF’s
在开始之前，请确保您已经 安装了 pdfminer.six。
以下代码示例展示了如何提取每个字符的字体名称和大小。本示例使用了 [simple1.pdf](https://raw.githubusercontent.com/pdfminer/pdfminer.six/master/samples/simple1.pdf)。
from pathlib import Path
from typing import Iterable, Any
from pdfminer.high_level import extract_pages
def show_ltitem_hierarchy(o: Any, depth=0):
"""显示 LTItem 及其所有子元素的位置和文本"""
if depth == 0:
print('元素 字体 描边颜色 文本')
print('------------------------------ --------------------- -------------- ----------')
print(
f'{get_indented_name(o, depth):<30.30s} '
f'{get_optional_fontinfo(o):<20.20s} '
f'{get_optional_color(o):<17.17s}'
f'{get_optional_text(o)}'
)
if isinstance(o, Iterable):
for i in o:
show_ltitem_hierarchy(i, depth=depth + 1)
def get_indented_name(o: Any, depth: int) -> str:
"""获取类名并添加缩进"""
return ' ' * depth + o.__class__.__name__
def get_optional_fontinfo(o: Any) -> str:
"""如果是 LTChar，则返回字体信息，否则返回空字符串"""
if hasattr(o, 'fontname') and hasattr(o, 'size'):
return f'{o.fontname} {round(o.size)}pt'
return ''
def get_optional_color(o: Any) -> str:
"""如果可用，则返回字体颜色信息，否则返回空字符串"""
if hasattr(o, 'graphicstate'):
return f'{o.graphicstate.scolor}'
return ''
def get_optional_text(o: Any) -> str:
"""如果可用，则返回 LTItem 的文本，否则返回空字符串"""
if hasattr(o, 'get_text'):
return o.get_text().strip()
return ''
path = Path('samples/simple1.pdf').expanduser()
pages = extract_pages(path)
show_ltitem_hierarchy(pages)
示例输出如下。请注意，它展示了布局元素的层次结构。布局算法将字符分组成行，并将行组合成框。框则出现在页面上。页面、框和行本身不会包含字体信息，因为字体可能在每个字符之间发生变化。示例中的描边颜色始终为 None，但如果 PDF 文件指定了颜色，该字段将包含颜色信息。
Before you start, make sure you have installed pdfminer.six.
The following code sample shows how to extract font names and sizes for each of the characters. This uses the [simple1.pdf](https://raw.githubusercontent.com/pdfminer/pdfminer.six/master/samples/simple1.pdf).
from pathlib import Path
from typing import Iterable, Any
from pdfminer.high_level import extract_pages
def show_ltitem_hierarchy(o: Any, depth=0):
"""Show location and text of LTItem and all its descendants"""
if depth == 0:
print('element font stroking color text')
print('------------------------------ --------------------- -------------- ----------')
print(
f'{get_indented_name(o, depth):<30.30s} '
f'{get_optional_fontinfo(o):<20.20s} '
f'{get_optional_color(o):<17.17s}'
f'{get_optional_text(o)}'
)
if isinstance(o, Iterable):
for i in o:
show_ltitem_hierarchy(i, depth=depth + 1)
def get_indented_name(o: Any, depth: int) -> str:
"""Indented name of class"""
return ' ' * depth + o.__class__.__name__
def get_optional_fontinfo(o: Any) -> str:
"""Font info of LTChar if available, otherwise empty string"""
if hasattr(o, 'fontname') and hasattr(o, 'size'):
return f'{o.fontname} {round(o.size)}pt'
return ''
def get_optional_color(o: Any) -> str:
"""Font info of LTChar if available, otherwise empty string"""
if hasattr(o, 'graphicstate'):
return f'{o.graphicstate.scolor}'
return ''
def get_optional_text(o: Any) -> str:
"""Text of LTItem if available, otherwise empty string"""
if hasattr(o, 'get_text'):
return o.get_text().strip()
return ''
path = Path('samples/simple1.pdf').expanduser()
pages = extract_pages(path)
show_ltitem_hierarchy(pages)
The output looks like below. Note that it shows the hierarchical structure of the layout elements. The layout algorithm groups characters into lines and lines into boxes. And boxes appear on a page. The pages, boxes and lines do not have font information because this can change for each character. The stroking color is always None in this example, but it will contain the color if the PDF does specify colors.
element font stroking color text
------------------------------ --------------------- -------------- ----------
generator
LTPage
LTTextBoxHorizontal Hello
LTTextLineHorizontal Hello
LTChar Helvetica 24pt None H
LTChar Helvetica 24pt None e
LTChar Helvetica 24pt None l
LTChar Helvetica 24pt None l
LTChar Helvetica 24pt None o
LTChar Helvetica 24pt None
LTAnno
LTTextBoxHorizontal World
LTTextLineHorizontal World
LTChar Helvetica 24pt None W
LTChar Helvetica 24pt None o
LTChar Helvetica 24pt None r
LTChar Helvetica 24pt None l
LTChar Helvetica 24pt None d
LTAnno
LTTextBoxHorizontal Hello
LTTextLineHorizontal Hello
LTChar Helvetica 24pt None H
LTChar Helvetica 24pt None e
LTChar Helvetica 24pt None l
LTChar Helvetica 24pt None l
LTChar Helvetica 24pt None o
LTChar Helvetica 24pt None
LTAnno
LTTextBoxHorizontal World
LTTextLineHorizontal World
LTChar Helvetica 24pt None W
LTChar Helvetica 24pt None o
LTChar Helvetica 24pt None r
LTChar Helvetica 24pt None l
LTChar Helvetica 24pt None d
LTAnno
LTTextBoxHorizontal H e l l o
LTTextLineHorizontal H e l l o
LTChar Helvetica 24pt None H
LTAnno
LTChar Helvetica 24pt None e
LTAnno
LTChar Helvetica 24pt None l
LTAnno
LTChar Helvetica 24pt None l
LTAnno
LTChar Helvetica 24pt None o
LTAnno
LTChar Helvetica 24pt None
LTAnno
LTTextBoxHorizontal W o r l d
LTTextLineHorizontal W o r l d
LTChar Helvetica 24pt None W
LTAnno
LTChar Helvetica 24pt None o
LTAnno
LTChar Helvetica 24pt None r
LTAnno
LTChar Helvetica 24pt None l
LTAnno
LTChar Helvetica 24pt None d
LTAnno
LTTextBoxHorizontal H e l l o
LTTextLineHorizontal H e l l o
LTChar Helvetica 24pt None H
LTAnno
LTChar Helvetica 24pt None e
LTAnno
LTChar Helvetica 24pt None l
LTAnno
LTChar Helvetica 24pt None l
LTAnno
LTChar Helvetica 24pt None o
LTAnno
LTChar Helvetica 24pt None
LTAnno
LTTextBoxHorizontal W o r l d
LTTextLineHorizontal W o r l d
LTChar Helvetica 24pt None W
LTAnno
LTChar Helvetica 24pt None o
LTAnno
LTChar Helvetica 24pt None r
LTAnno
LTChar Helvetica 24pt None l
LTAnno
LTChar Helvetica 24pt None d
LTAnno