PDF to Text, a challenging problem

Below is a PDF. It is a .txt file. I can save it with a .pdf extension and open it in a PDF viewer. I can make changes in a text editor. For example, by editing this text file, I can change the text displayed on the screen when the PDF is opened, the font, font size, line spacing, the maximum characters per line, number of lines per page, the paper width and height, as well as portrait versus landscape mode.

   %PDF-1.4
   1 0 obj
   <<
   /CreationDate (D:2025)
   /Producer 
   >>
   endobj
   2 0 obj
   <<
   /Type /Catalog
   /Pages 3 0 R
   >>
   endobj
   4 0 obj
   <<
   /Type /Font
   /Subtype /Type1
   /Name /F1
   /BaseFont /Times-Roman
   >>
   endobj
   5 0 obj
   <<
     /Font << /F1 4 0 R >>
     /ProcSet [ /PDF /Text ]
   >>
   endobj
   6 0 obj
   <<
   /Type /Page
   /Parent 3 0 R
   /Resources 5 0 R
   /Contents 7 0 R
   >>
   endobj
   7 0 obj
   <<
   /Length 8 0 R
   >>
   stream
   BT
   /F1 50 Tf
   1 0 0 1 50 752 Tm
   54 TL
   (PDF is)' 
   ((a) a text format)'
   ((b) a graphics format)'
   ((c) (a) and (b).)'
   ()'
   ET
   endstream
   endobj
   8 0 obj
   53
   endobj
   3 0 obj
   <<
   /Type /Pages
   /Count 1
   /MediaBox [ 0 0 612 792 ]
   /Kids [ 6 0 R ]
   >>
   endobj
   xref
   0 9
   0000000000 65535 f 

0000000009 00000 n 0000000113 00000 n 0000000514 00000 n 0000000162 00000 n 0000000240 00000 n 0000000311 00000 n 0000000391 00000 n 0000000496 00000 n trailer << /Size 9 /Root 2 0 R /Info 1 0 R >> startxref 599 %%EOF

It can also have embedded binary streams. It was not made for text. It was made for layout and graphics. You give nice examples, but each of those lines could have been broken up into one call per character, or per word, even out of order.