如何使用 PDFMiner 在 Python 中提取 PDF 中文本的字体颜色？

Question

如何从 PDF 中的文本中提取字体颜色？

我已经尝试使用 PDFMiner 来探索LTText或LTChar对象，但似乎该模块只允许提取字体大小和样式，而不是颜色。

Answer 1

我查看了PDFMiner（未维护）和PDFMiner.Sixth（fork）的所有源代码。这两个Python模块都不允许您提取颜色。在两个模块的问题部分中，提取字体颜色是一个常见问题。

我还查看了PDFPlumber，它使用 PDFMiner.Sixth。该模块提取字体颜色。提取的颜色元素包括stroking_color（字符的轮廓）和non_stroking_color（字符的填充）。我查看了从示例 PDF 中提取的颜色，它们与 RGB 颜色相匹配。

import pdfplumber

pdf_file = pdfplumber.open('path_to_pdf')
for p, char in zip(pdf_file.pages, pdf_file.chars):
    words = p.extract_words(keep_blank_chars=True)
    texts = p.extract_text()
    print(f"Page Number: {p.page_number}")
    print(f"Font Name: {char['fontname']}")
    print(f"Font Size: {char['size']}")
    print(f"Stroking Color: {char['stroking_color']}")
    print(f"Non_stroking Color: {char['non_stroking_color']}")
    print(texts.strip())
    print('\n')

未回答的问题是：

如何提取字体颜色并仍然使用 PDFMiner 代码？

下面的代码允许我同时使用PDFMiner.Sixth和PDFPlumber从源 PDF 文件中提取各种元素，例如文本、字体名称、字体大小、stroking_color 和 non_stroking_color。

import pdfplumber

from pdfminer.high_level import extract_pages
from pdfminer.layout import LTTextContainer, LTChar


with open('path_to_pdf', 'rb') as scr_file:
    with pdfplumber.PDF(scr_file) as pdf_file:
        for page_layout, char in zip(extract_pages(scr_file), pdf_file.chars):
            for element in page_layout:
                if isinstance(element, LTTextContainer):
                    for text_line in element:
                        for character in text_line:
                            if isinstance(character, LTChar):
                                print(element.get_text())
                                print(f"Font Name: {character.fontname}")
                                print(f"Font Size: {character.size}")
                                print(f"Stroking Color: {char['stroking_color']}")
                                print(f"Non_stroking Color: {char['non_stroking_color']}")
                                print('\n\n')

更新 03-09-2021

我仍在致力于将这些功能啮合和同步在一起。我检查了它们，它们似乎输出了正确的元素。

import pdfplumber
from pdfminer.high_level import extract_pages
from pdfminer.layout import LTTextContainer, LTChar, LAParams


def extract_character_characteristics(pdf_file):
    number_of_pages = len(list(extract_pages(pdf_file)))
    for page_layout in extract_pages(pdf_file, laparams=LAParams()):
        print(f'Processing Page: {number_of_pages}')
        number_of_pages -= 1
        for element in page_layout:
            if isinstance(element, LTTextContainer):
                for text_line in element:
                    for character in text_line:
                        if isinstance(character, LTChar):
                            if character.get_text() != ' ':
                                print(f"Character: {character.get_text()}")
                                print(f"Font Name: {character.fontname}")
                                print(f"Font Size: {character.size}")
                                print('\n')


def extract_character_colors(pdf_file):
    with pdfplumber.PDF(pdf_file) as file:
        for char in file.chars:
            if char['text'] != ' ':
                print(f"Page Number: {char['page_number']}")
                print(f"Character: {char['text']}")
                print(f"Font Name: {char['fontname']}")
                print(f"Font Size: {char['size']}")
                print(f"Stroking Color: {char['stroking_color']}")
                print(f"Non_stroking Color: {char['non_stroking_color']}")
                print('\n')


with open('test.pdf', 'rb') as scr_file:
    extract_character_characteristics(scr_file)