4 Replies Latest reply on Jun 1, 2017 4:43 PM by Geobop

    Best Resolution for Epubs

    Geobop Level 1

      I was reviewing Kindle's publishing guidelines, and they recommend a resolution of 300. I checked my project files, and they all have a resolution of 600. That's a relief, because I thought I was using a default resolution of 72, so I should be OK.


      However, I wondered if 600 might be overkill. If I have a huge file (e.g. 100 MB) with a resolution of 600, and I changed it to a resolution of 300, what kind of file size should I expect?


      I copied one of my files and changed the resolution, but my experiment didn't accomplish anything. I tried changing it with and without "resample" selected, but my image dimensions changed either way. I compared the file sizes of the original (resolution 600) and the new one (300) and there was no change.


      I guess I should ask two questions:


      1) What should I use as a default resolution for my epub projects?


      2) If the answer is 300, then should I change all my files that have a resolution of 600, or is that more trouble than it's worth?


      Also, should I choose 8 bit, 16 bit or 32 bit? (8 is selected by default.)



        • 1. Re: Best Resolution for Epubs
          JJMack Most Valuable Participant

          You should take a course to learn the basics of digital image processing. Also ask your publisher what they want from you.


          You clearly do not know how thing work and what you said you did clearly you did not to Right


          If you resize without resampling  and change the resolution the will be no change in the number of Pixels   or File size that just changes the Printer pixel size. The printed image size will change because of the change in pixel size.


          If you resize with resample change the resolution you need to specify the interpolation method to use. The Number of Pixels will change the file size will change the Printer Pixel size will change but the pint image size will not change.

          • 2. Re: Best Resolution for Epubs
            mostafaa13494434 Level 1

            If you are working in Fixed Layout Books, the resolution of the page is what you define it to be, however 738x985  is what Apple says their full screen, single page resolution is in iBooks.ویلا


            Individual images can have up to 2million pixels (LxW). Having a bigger image, that you scale down to the max resolution is always better, if the file size of the image doesn't affect performance.دکوراسیون داخلی


            1107x1478 is 1.5x the size of the single page resolution, and is 1.6 million pixels. Doing a bit of jpeg compression should yeild manageable file sizes, and look very good. I try to keep my backgrounds 400kb or less if I can.طراحی نما

            1 person found this helpful
            • 3. Re: Best Resolution for Epubs
              Geobop Level 1

              Yes, Apple and Kindle apparently have different preferences, and their preferences apparently differ again between cover pictures and regular images.


              It sounds like I'm OK, or at least better off than I would be if my resolution was too low. I'll give jpg compression a try. Thanks.

              • 4. Re: Best Resolution for Epubs
                Geobop Level 1

                However, I'm still interested in hearing from people who actually work with epubs and can tell me what default resolutions they work with.