PDF是一種普遍存在的文件格式，它非常適合在共享文件的同時保留字型、影象和跨平臺的總體佈局。但是，在從文件中複製和貼上文字時，有沒有一種簡單的方法來保留這種格式？

今天的問答環節是由SuperUser提供的，SuperUser是Stack Exchange的一個分支，是一個由社群驅動的問答網站分組。

問題

超級使用者閱讀器Colen正在尋找一種從PDF中提取文字的方法，同時保留格式：

When I copy text out of a PDF file and into a text editor, it ends up mangled in a variety of ways. Formatting like bold and italics are lost; soft line breaks within a paragraph of text are converted to hard line breaks; dashes to break a word over two lines are preserved even when they shouldn’t be; and single and double quotes are replaced with ? signs.

Ideally, I’d like to be able to copy text from a PDF and have formatting converted to HTML codes, “**art quotes” converted to ” and ‘, and line breaks done properly. Is there any way to do this?

對於Colen（和我們其他人）來說，有沒有一種既快速又簡單的方法可以在不犧牲格式的情況下獲取抓取文字？

答案

超級使用者貢獻者Frabjous提供了一個結合了大量謹慎的解決方案：

Firstly, you have to understand what a PDF is. PDFs are designed to mimic a printed page, and they are designed only as an output format, not an input format. a PDF is basically a map containing the exact location of characters (individual letters or punctuation, etc.) or images. In most cases, a PDF does not even store information about where one word ends and another begins, much less things like soft breaks vs. hard breaks for paragraph endings.

(A few recent PDFs do store some information about this stuff, but that’s a new technology, and you’d be lucky to find PDFs like that. Even if you did, your PDF viewer might not know about it.)

Anyway, it’s up to your software to implement some kind of “artificial intelligence” to extract merely from the locati*** of individual characters what is a word, what is a paragraph, and so on. Different software is going to do this better than others, and it’s also going to depend on how the PDF was made. In any case, you should never expect perfect results. Having the output PDF is not the same as having the source document. Far better to try to obtain that if you can.

The standard solution to your kind of problem is to use Adobe Acrobat Professional (the expensive one, not the free reader) to convert the PDF to HTML. Even that is not going to get perfect results.

There is free software that can be used to extract text from PDFs with some of formatting intact, but again, don’t expect perfect results. See, e.g., calibre (which can convert to RTF format), pdftohtml/pdfreflow, or the AbiWord word processor (with all import/export plugins enabled). There’s also a PDF import plugin for OpenOffice.

But please don’t expect perfection with any of these results. You’re going against the grain here. PDF just is not meant as an editable input format.

如果你很難決定從哪個工具開始，Calibre是一個名副其實的檔案瑞士**。您還可以使用它來轉換PDF檔案，以便在電子書閱讀器上使用，並組織電子書/文件庫。

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