6 Replies Latest reply on Jun 1, 2015 9:41 AM by SGPrintshop

    Exporting to PDF with no compression still changing raster images.

    SGPrintshop

      When exporting to PDF with compression turned off, my images are still being processed and anti-aliased. How do I prevent that from happening? My goal is to output a print scale proof to clients (frequently pixelated) using the proof template I set up in InDesign so that it still shows the level of pixelation that will occur in the RIP.

        • 1. Re: Exporting to PDF with no compression still changing raster images.
          rob day Adobe Community Professional & MVP

          Choose Do Not Downsample from the sampling pop-up. Some RIPs will still downsample images over a certain threshold, which can be a problem for color or grayscale images that include line art or small text that needs more resolution than the rule-of-thumb 300ppi.

          • 2. Re: Exporting to PDF with no compression still changing raster images.
            SGPrintshop Level 1

            Hi Rob,

             

            By "sampling pop-up" do you mean the compression tab in the PDF export

            options? If so, I've set all those to Do Not Downsample. Attached is an

            image showing what is happening. On the right is the original TIF showing

            the client the level of pixelation, on the left is the exported PDF zoomed

            in to approximately the same scale. There seems to be a certain amount of

            anti-aliasing that is happening. Is there a way to turn off any image

            processing for linked images? Should the image be a specific type to

            prevent this?

             

            Thanks for the quick reply,

            Nate

            • 3. Re: Exporting to PDF with no compression still changing raster images.
              rob day Adobe Community Professional & MVP

              To attach files, you have to use the camera icon in the forum web reply field.

               

              You can't compare Acrobat's and Photoshop's previews to know what's going on with the compression or sampling because they use different view scaling, and what you are seeing might be the previews getting scaled differently to fit the window. Photoshp's 100% view is a 1:1 monitor to image pixel ratio, while by default Acrobat's 100% equals the print output size, so it's difficult to exactly compare pixels.

               

              You have to use Acrobat's Object Inspector to know if there is sampling or compression. So with this Export setting:

               

              Screen Shot 2015-06-01 at 10.53.49 AM.png

               

              I can compare InDesign's Link panel's image info with Acrobat's Object Inspector and see that the image hasn't changed on export. The pixel dimensions and ppi are the same, and Object Inspector's Filters: is blank meaning the image has no compression:

               

              Screen Shot 2015-06-01 at 10.59.32 AM.png

              • 4. Re: Exporting to PDF with no compression still changing raster images.
                SGPrintshop Level 1

                Screen Shot 2015-06-01 at 10.52.43 AM.pngScreen Shot 2015-06-01 at 10.53.00 AM.png

                Thanks. What I see in ID is that the link is a TIFF type, but when it exports it has a JPEG filter applied to it. Is that what's causing the image distortion (seen below)? The image below is in Preview in MacOSX. On the left is the exported PDF and on the right is the original TIF file.

                Screen Shot 2015-06-01 at 9.22.48 AM.png

                • 5. Re: Exporting to PDF with no compression still changing raster images.
                  rob day Adobe Community Professional & MVP

                  Are you sure you are setting Compression to None as I have in my capture (in addition to Do Not Downsample)? Also, OSX Preview is renown as a bad PDF reader. Acrobat Reader and AcrobatPro also have Preferences>Page Display, which affect the preview. Your 19ppi res is unusually low, so the display pref might be more noticeable.

                  • 6. Re: Exporting to PDF with no compression still changing raster images.
                    SGPrintshop Level 1

                    It looks like the viewer is the issue. I used to hate using Acrobat because it took forever to load and was slow and clunky in its actions. The new version seems to be better. I'll try using that from now on since most people probably use Acrobat reader to view these things anyway. I'll let our team know. Attached is a screen cap of the same file viewed in Preview (left) and Acrobat Pro (right). Thanks for your help. It was driving me nuts. The point of the whole thing is to show the client that 19 ppi is way too low a resolution for a final print. The original was sent scaled down to us but at 150 ppi.

                    Screen Shot 2015-06-01 at 11.38.48 AM.png