Body: <p>I have found that some archived versions of old textbooks use DJVU files. From what I understand, the DJVU file only contains text, but perhaps I am wrong about that and there is some additional image data that is not shown in an e-reader.</p>
  <p>Archiving something like a math textbook using this format feels strange, as the equations are converted to seemingly random characters. Presumably this is just a result of an OCR software that converts the symbols to the closest ascii characters. Is there any logic to this?</p>
  <p>Does there exist some way to decode the DJVU file to some other format (e.g. PDF but maybe also postscript or latex?) to recover the equations? Or is that information just lost?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-04-18T22:49:47.127Z
Comments.Text: Try an online converter such as https://www.zamzar.com/convert/djvu-to-pdf/ or https://djvu2pdf.com/, or software such as http://www.pdflite.com/djvu-to-pdf/ . Before installing any software, check it at VirusTotal.
Comments.UserDisplayName: DrMoishe Pippik
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-04-19T08:31:46.667Z
Comments.Text: @DrMoishePippik I did try with Calibre but it wasn't helpful and just gave the same broken equations.
Comments.UserDisplayName: John
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-04-19T15:37:43.450Z
Comments.Text: Correct, Calibre currently can only convert djvu text: https://www.mobileread.com/forums/showthread.php?t=257162 . That was *not* suggested.
Comments.UserDisplayName: DrMoishe Pippik
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2023-05-25T18:22:37.313Z
Comments.Text: @John (sorry for the belated comment) first of all, what do you use to display a djvu file? second: could you upload a screenshot of a snippet of a page with formulas? (just a snippet in order not to incur in copyright violation)
Comments.UserDisplayName: mau
Tags: <conversion><djvu><ocr>
Title: How to open/convert a DJVU file of a math textbook which contains equations?
UserDisplayName: John
ThreadText: # How to open/convert a DJVU file of a math textbook which contains equations?
  
  (Asked by: username_0 on 2023-04-13)
  
  I have found that some archived versions of old textbooks use DJVU files. From what I understand, the DJVU file only contains text, but perhaps I am wrong about that and there is some additional image data that is not shown in an e-reader.
  
  Archiving something like a math textbook using this format feels strange, as the equations are converted to seemingly random characters. Presumably this is just a result of an OCR software that converts the symbols to the closest ascii characters. Is there any logic to this?
  
  Does there exist some way to decode the DJVU file to some other format (e.g. PDF but maybe also postscript or latex?) to recover the equations? Or is that information just lost?
  
  **Tags:** conversion, djvu, ocr
  
  > **Comments:**
  > **username_1**: Try an online converter such as https://www.zamzar.com/convert/djvu-to-pdf/ or https://djvu2pdf.com/, or software such as http://www.pdflite.com/djvu-to-pdf/ . Before installing any software, check it at VirusTotal.  
  > **username_0**: @DrMoishePippik I did try with Calibre but it wasn't helpful and just gave the same broken equations.  
  > **username_1**: Correct, Calibre currently can only convert djvu text: https://www.mobileread.com/forums/showthread.php?t=257162 . That was *not* suggested.  
  > **username_2**: @username_0 (sorry for the belated comment) first of all, what do you use to display a djvu file? second: could you upload a screenshot of a snippet of a page with formulas? (just a snippet in order not to incur in copyright violation)  
  
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  ## 0 answers
  
  