5 Replies Latest reply on Aug 8, 2012 3:51 PM by rob day

    PNG resolution in ID


      Only recently have I come to be playing with screenpics quite a bit, and while usually I'll use any of an assortment of annotation apps to quickly mark them up, I've come to have to do a more robust instructional document, so I figured I'd use ID. I've never played with PNGs really, so I'm not familiar with their characteristics. Basically, I've taken some screenshots of various panes, and also iPhone shots, and am placing them into a step-by-step document. But whenever I resize the image files -- specifically, reduce them in size to around 30% -- they loose resolution to the point of virtually useless.


      I went over to AI and it seems to do same thing.


      What am I missing?


      I'm on a MBP with 10.8, and ID 5.5.



        • 1. Re: PNG resolution in ID
          Peter Spier Most Valuable Participant (Moderator)

          That shouldn't be happening, so maybe it's the display settings. Try View > Display Performance > High Quality Display.


          You can set that as the default in your prefs.


          Keep in mind, though, that screen caps are low res to start with. They never look great.

          • 2. Re: PNG resolution in ID
            rob day Adobe Community Professional & MVP

            Is this for print or screen viewing.


            Output resolution increases when you scale down—a 72 ppi image has an effective print resolution of 240ppi when you scale it to 30%. So if the output is print the screen capture's text will be fully resolved, but it will be 3x smaller and harder to read.


            If the output is a screen you're up against the screen's resolution, which isn't likely to be 240ppi, so the layout needs to be zoomable like a PDF

            • 3. Re: PNG resolution in ID
              akrengel Level 1

              Interesting. That worked. Thanks!


              I didn't think of that, as I wasn't so much concerned with "display resolution", and I just assumed ID was set on some comp setting -- with final output being original.

              But once I had exported to High Qualtiy PDF etc., it still came out as funny as it looked on screen.


              Still confusing terminology and correlation to me, but hey, it works.

              • 4. Re: PNG resolution in ID
                akrengel Level 1

                Rob, it's possibly for both. It's a PDF I would send, that they could well possibly print out.


                It seems iPhone caps, and the screen caps, are 72ppi. When I place a phone cap on the page, it's displayed at 8.5"x12.5". Nutty. When I reduced it, it got pixelated --  even when exporting to HQ PDF. Peter's suggestion of changing the display resolution actually solved it -- as far as PDF display on my own personal screen goes.


                I was simply confused because regardless what I resize the caps to in a dedicated cap editting tool, like Clarify, Skitch, etc., it renders perfectly at any size.


                I wonder what the best method is. I'm not doing anytthing revolutionary here! There are simple ste-by-step tutorials using screen caps as reference in all corners of web and print. I guess these screen cap programs have a dedicated engine or something. I've been working with PS and AI for almost 20 years, and the whole ppi/resolution thing still confuses the hell out of me some times...

                • 5. Re: PNG resolution in ID
                  rob day Adobe Community Professional & MVP

                  When I place a phone cap on the page, it's displayed at 8.5"x12.5". Nutty.


                  Not nutty. The iPhone screen capture is 612 x 900 pixels (the full iphone 4 screen is 640x960), so 612/72=8.5 and 900/72=12.5.