Map Enthusiasts @sopuli.xyz Flying Squid @lemmy.world 4w ago

Acrobat 7’s maximum PDF size limit (381 km²) overlaid on Germany

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I believe that is 381 km squared, not 381 square kilometers. Vastly different areas. Germany is much larger than 381 square kilometers.
- Oops. You are correct. Thank you. Fixing.
  
  If it's a square 381km x 381km then that's 145161km² (and I'm not aware that there's any difference between "square kilometres" and "kilometres squared", is there?)
  
  The title still looks wrong to me
  
  Probably should take this post down, since it’s misleading.
- 381² k²m²
Some questions...

How is this measured in sq km, rather than something digital such as pixels?

Why is it 381? How did they arrive at that number?

Why is there any limit at all, if it's this big?
- Beginning with PDF 1.6, the size of the default user space unit may be set with the UserUnit entry of the page dictionary. Acrobat 7.0 supports a maximum UserUnit value of 75,000, which gives a maximum page dimension of 15,000,000 inches (14,400 * 75,000 * 1 ⁄ 72). The minimum UserUnit value is 1.0 (the default).
  
  15 million inches happens to be exactly 381 km Source
  
  That's sooooo arbitrary.
- To satisfy the anything but metric postulate: 381 km originally are 15 million inches.
  
  However, using some tricks, the size isn't limited to that.
  
  https://alexwlchan.net/2024/big-pdf/
  
  Remark: The side length of the square correspods to 381 km, subsequently, its area is 145161 km^2 .
  381 km^2 are slightly smaller than the city of Cologne.
  
  Good to see Germany won't run out of PDF for their digital mapping efforts and need a costly replacement.
Ok, now where can we get a printer to print that?
- a global network of printers
  
  A national network will suffice.
- I think the play would be to get one that's modular (I suspect it's been done) and just keep building it out. The trick would be if the Earth is flat enough of it to sit nicely on. If not, you could cheat by slightly changing the DPI further from the center, so it would be a sphere section.
What is the smallest file size possible for a black PDF of this size? How about one with a solid color pattern, or a standard pattern?
- Physical size is just a parameter, unless you insert formatting and stuff which needs to save data per page/region. Otherwise you can have just vector graphics of fixed data size which gets scaled on rendering to fit the physical limit.
  
  So you could have a very small file that has a huge area, got it!
funny, because adobe illustrator shits itself at a couple m²
DWG enthusiasts in tatters.

25 comments