Support » Plugin: Perfect Images + Retina » Could you generate the 2x images with double DPI?

  • Resolved born2webdesign


    Hi, I typically upload an optimised 2x image as the original – so I set it to 600 DPI (for printing), but then all images are generated with 600 DPI set …
    I would rather generate my original (2x) image with 300 DPI, have all WP-generated images with 300 DPI, and only the ones generated by WP-retina-2x with 600 DPI.
    Right now, my image.jpg and the (max size) image-1280×720@2.jpg are bit-identical – I would love for the @2.jpg to be the same as the original _except_ for the DPI setting (orig 300, @2 600).

    TIA for considering!

Viewing 4 replies - 1 through 4 (of 4 total)
  • Plugin Author Jordy Meow



    I believe you are making a mistake here 🙂 You are mixing real DPI with the DPI written in the file.

    Let’s take in consider a placeholder of 400px of width. An image inside of 400px would be 1:1 pixel ratio. If the image is 800px, then we should have a 2:1 ratio. It’s what we call Retina but than ratio can be more or less 2:1.

    Same for the print, except the placeholder is a size in “the real world”. Like centimers, in my case. If you generate an image of 300DPI to fit this placeholder, then for a smaller placeholder, the real DPI would be 600DPI. Of course, the file information would still display 300DPI (as that’s what written into the file). But Adobe InDesign or Affinity Publisher are clever enough to calculate that real/effective DPI for you, and even display warnings if it’s too low.

    Hi Jordy,

    I believe you are making a mistake here

    I believe I’m not—just not too clear, either 😉

    I am talking about people printing webpages—yes, they still do exist 😉
    Maybe browsers have become better at this (maybe srcset magically helps here, too?), but I remember that (perhaps unstyled?) images printed on paper would be resized according to their DPI setting, so an image that looked the right size in the browser might be too big/small on paper. That is why I would like to have the (approximate) correct DPI set for the image (as authored, by myself (or Adobe—which I don’t use), then doubled for 2x images).

    Of course, this is not the most important feature, as we don’t see any of this in the browser, but would be nice to have 🙂

    Plugin Author Jordy Meow


    I actually understood 🙂 It’s more or less related to my third paragraph. But that would depend on how the page is printed, witch which settings.

    But in fact, you don’t need to worry much. If it’s done from the web, I am pretty sure the printing features of Chrome and other browsers are clever enough to use the src-set and get the right size for it. Still, the DPI doesn’t matter here 🙂

    Best way to convince you? In fact… try it 🙂

    Maybe I am wrong but I doubt the images would be resize depending on their DPI, or printed with less quality. I don’t see the point of doing that, that would make things extremely complicated for the users and developers.

    Thanks—I hade already checked in Firefox and Chromium, and, indeed, they seem to cope. Thus not very important, I agree.
    But as I thought it would have been a minor addition to simply generate the 2x images with double the original’s DPI, I thought it would have been nice for some edge cases where DPI does matter …
    Anyway, thank you for your time!

Viewing 4 replies - 1 through 4 (of 4 total)
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