NewComputerExpress UK 012.pdf

Anyone know how to get PDF resolution to be recognised correctly? This one is really 1440P, but retrocdn thinks it's only 212P--Pirate Dragon (talk) 11:40, 3 April 2020 (EDT)

Technically it is being recognised correctly.

The system generates thumbnails based on the width/height information stored in the PDF, and this one claims the page size is 1.55 x 2.21 inches.

Which means, if rendered on a 96dpi display, the calculation comes out as 2.21 x 96 = 212.16, which is rounded off as 212. I think this means if you measure the thumbnail with a ruler, you'll get those values in inches (assuming you're using a 96dpi display (and that's a big assumption - I'm not!))

The solution is to edit the PDF. But I don't know how to do that cleanly.

It's probably making the right decision, as most PDFs in the world consist of just text, so it needs something to determine the page size. In our case, we'd want the page sizes to be automatically calculated based on the size of the image.

... and it's doing that too! Because even though the dimensions of that first JPEG are 929x1328 pixels... the JPEG also says it's 600dpi. (1328/600) * 96 = 212-ish.

So it's actually 100% correct... if you care at all about dpi. Which we don't (and the old PDF extension didn't either), so it looks like garbage. -Black Squirrel (talk) 16:30, 3 April 2020 (EDT)

Yeah it's quite the interesting subject

File:NewComputerExpress UK 012.pdf File:NewComputerExpress UK 012.pdf

File:ODM UK 01.pdf File:ODM UK 01.pdf

dpi does matter and we should care - [1]. The problem is PDFs can be quite big, so uploading new versions is awkward (and knowing you need to upload a new version is even more awkward) -Black Squirrel (talk) 17:29, 3 April 2020 (EDT)

I always check the dimensions of a pdf before I upload it. If it's too small I use this program to losslessly set the jpegs' dpi to 96 and recompile. - Hivebrain (talk) 17:45, 3 April 2020 (EDT)

Brilliant, that fixed it, thanks! I was reducing the resolution of the images to a more reasonable size without also reducing the dpi. I think the native dpi of my 2160p monitor is 157.35, but I'm running it at 1080p, so my actual dpi should be 78.68, I don't suppose that really matters though. I can set the dpi in photoshop when I'm batch processing the images, so no biggy, just need to redo the ones I've already uploaded, which is a bit of a pain as I've already deleted the originals.--Pirate Dragon (talk) 05:51, 4 April 2020 (EDT)