pdf.md

PDF (Portable Document Format)

不能複製文字 ?? {: #copy-text }

• Can’t Copy Text from a PDF File?
  • You can quickly check to see if a PDF file is secured in Adobe Reader by looking up in the title bar and looking for the word SECURED.
  • You can see specific permissions by clicking on Edit and then clicking on Protection and then Security Properties.
  • As you can see below, content copying is not allowed and the security is PROTECTED BY A PASSWORD. If you know the password, then you could remove the security and copy all you want.
  • Unless you’re a hacker, breaking the password is not an option. So the only other thing you can do is take a screenshot of the text and then run it through an OCR program. Sounds like too much work, but it really is not. You can take a screenshot on a Mac or PC without additional software.

工具：

• Free Online OCR - Convert JPEG, PNG, GIF, BMP, TIFF, PDF, DjVu to Text 上傳 PDF 後，切換不同的頁次 (甚至選取範圍)，就可以得到該頁 OCR 的結果。

Text Extraction ??

• Xpdf
• PDFMiner

參考資料：

• Related Projects - PDFMiner

  • "PDFMiner is about 20 times slower than other C/C++-based counterparts such as XPdf."，所以 XPdf 是更好的選擇?
  • 其他相關的專案還有 pyPdf (停止維護)、PDFBox (現在的 Apache PDFBox?)、MuPDF。