PDF Statistics - Page Boxes Not Equal - Canva

[RunDontStop]

I use this statistics feature all the time when comparing PDF page size to job specs.

I had an interesting result today with a PDF created in Canva (I know, pretty awful). The stats flags the PDF as having page boxes not equal.

However, looking through the PDF, all pages are the same size.

I decided to check in PitStop using the Preflight check for pages different sizes, and again it was flagged for different page sizes.

Then I checked the Media Box origin. It was not at 0,0. I set it to 0,0 in Acrobat. This is easy fix in PitStop or Acrobat.

Running it back through the stats check again after this fix, all page boxes are equal.

So my question is: why exactly is this origin a factor when comparing page sizes within a PDF? All of the boxes: Media, Crop, Art, trim and bleed - are identical. It was just the origin was not zeroed out. My understating is the origin has no bearing on the content or size, it's just a measurement point of reference.

[freddyp]

Your remark about the origin is valid. In order to investigate further, can you share the original file please?

[RunDontStop]

Sorry I am just now getting back to this. The file was too large to upload. But I deleted all content to get file size down. Checked again and the blank PDF still produced the pages not same size result.

But the file size was still too large. Output intent added size. I removed the output intent in Acrobat. Processed this file, and then the pages all read the SAME size in Switch. This is without resetting origin.

Thoroughly puzzled, I went back through the deletion process again with the original file, and then removed the output intent in PitStop. This PDF does produces all pages NOT the same size result, as the original PDF.

If I take this PDF and set the origin to 0,0 in PitStop, the pages then all read the same size. So the origin does seem to have something to do with it.

Regarding the Acrobat removal of output intent changing the outcome – I took the original file with all content as yet another test, removed output intent in Acrobat, and ran that through to check page sizes. In that case, all pages not the same size is the result. But, for whatever reason, blank PDF with output intent - if I remove the intent in Acrobat, and leave the origin alone, the pages read the same size.

To summarize

1. The attached PDF shows in Switch as having pages of unequal size
2. If you set origin to 0,0 in Acrobat, pages come through all same size
3. If you set origin to 0,0 in in PitStop, all pages come through the same size.

[freddyp]

The last page of the document has an origin that is different from that of the other pages and that is indeed the reason why [Stats.PageBoxesEqual] returns False. Well, nothing new, you had already figured that one out.

I logged it as a bug, but I am anticipating a bit of a debate. If you look at the internals of the PDF file you see that there is a difference between the last but one and the last page, so the boxes are not equal. However, the sizes are equal when you do the math, so the page boxes are equal. Which one is it? I am on your side . The output intent has nothing to do with this. The only explanation I can see is that the origin was reset by Acrobat when saving the file after you removed the output intent.

Screen Shot 2023-02-22 at 11.21.11.png (147.01 KiB) Viewed 3294 times

[JimmyHartington]

My input in the debate would also be that the sizes should be considered to equal.
Otherwise you get confused as a user of Pitstop Pro, since the Media Box origin is probably not known among all users.

[RunDontStop]

Thank you for your insight and logging as bug! It's worth a shot anyway.