10 Replies Latest reply on Jul 23, 2016 3:46 PM by Abambo

    Best way to scale down big images

    badpixxxel Level 1

      Hello,

      I am working on an A5 format brochure needed for print and I really don't know how to work with images. I've read dozens of posts and tutorials, but I have the feeling I am doing something wrong, that's why I am asking for your help. It's the first time I work in ID and I can't use my friend's computer for more than 1 hour daily to work on this project.

       

      The brochure:

      - A5 format, 6 pages

      - 1 logo

      - 3 images for full page backgrounds

      - 1 medium image

      - 6 images in small 6.2x4.3cm frames

      - some text

       

      I will use some images I took with my digital camera (3872 x 2592 at 240dpi) and some I found on the internet as free images. The issue I have is with the images for the 6 small containers measuring 6.2x4.3cm in ID. I have the feeling the images I have are too big for those small frames and I need to scale them down.

       

      Tried different workflows with the six images, but every one of them has problems:

      1. Opened RAW/JPG image in PS, processed the image, cropped, decreased image size by 50-60% without resampling and saved as .tiff. This will increase resolution and I will end up with a big file size (9MB). Avoided saving as .jpeg because of loss of data (however doing this will give nice file sizes).

      2. Placed original image in ID and used the Transform->Scale to downsize it to the container size. The problem is the resolution of the image gets sky high and the pixels seem "crowded" (Changed Display performance to High Quality Display but still no change), which I'm afraid will look bad when printed. I know the resolution will be decreased to 300dpi when exporting to PDF, but still.

       

      Q#1 What/how to do with those big images to make them suited for printing in small areas of a brochure?

      Q#2 Not related to my main question: How does assigning the frame content as "Graphic" affects the final print output?

      Q#3 Can I leave the colorspaces and ICC profiles as they are (RGB, CMYK / sRGB, Adobe RGB, U.S. Web Coated (SWOP) V2) and hope the printer will take care of conversion to CYMK or should I convert each one of them separately in PS?

       

      I don't know if it's a real issue or if I succeeded in explaining everything, I hope I don't annoy anybody with my questions.

       

      Thank you!

        • 1. Re: Best way to scale down big images
          Derek Cross Level 6

          Are you sure the brochure is 6 pages and not 8 pages?

          If you have Photoshop you can size the images easily in that and Place them in InDesign (though you can also resize them in InDesign too).

          Ensure your images are between 200 and 300 PPI (you can check the Effective Resolution in the InDesign Links panel.

          Work in sRGB color space.

          Don't forget to add bleed to the full page images

          Export your brochure as separate pages (not spreads) PDF selecting the Adobe PDF Preset PDF/X-4 and tick use Document Bleed Settings (unless your printer supplies another spec).

           

          And there's no problem about asking questions on this friendly forum. Though doing a bit of training would help you in the long run.

           

          P.S. to work out the image size, in your example, divide 3872 x 240 and 2592 by 240 = 16" x 11" printing size, yes too large.

          An image that's print at A5 at 300 PPI should have dimensions of around 1800 px x 2500 px

          • 2. Re: Best way to scale down big images
            badpixxxel Level 1

            Thank you Derek for your prompt answer and advices regarding exporting the whole stuff.

             

            You are right about the number of pages, I didn't count the covers, now I realize it's a noob mistake. They are indeed 8 pages in total.

            Thanx for putting my mind at ease about color spaces, I'll leave them in RGB.

             

            As for the big images resolution, I still don't understand how to calculate the right scaled-down dimensions and dpi, to fit (almost) perfect in an ID image frame with known dimensions. From what I read, downscaling or upscaling for more than 20% creates image quality issues at printing. I hope it makes sense.

             

            I'll do my best to learn some ID secrets, I only worked with it for about a couple of hours in total, and it's my first brochure ever.

            • 3. Re: Best way to scale down big images
              Derek Cross Level 6

              Don't worry too much about down-scaling an image from high to low resolution, it's upscaling from a low resolution image that will cause you problems.

               

              Understand that PPI (pixels per inch), times the size you want to print the image will give you the size in pixels you need to Place in your InDesign document.

               

              So if you want an image to print 2" x 3", the pixel dimensions should be (at 250pp) –  250 x 2 and 250 x 3 which means your image needs to  be 500px x 750px.

               

              This tutorial on Placing images may help: http://www.digitalartsonline.co.uk/tutorials/adobe-indesign/how-insert-image-into-indesign -document/

              1 person found this helpful
              • 4. Re: Best way to scale down big images
                rob day Adobe Community Professional & MVP

                From what I read, downscaling or upscaling for more than 20% creates image quality issues at printing. I hope it makes sense.

                 

                I'll do my best to learn some ID secrets, I only worked with it for about a couple of hours in total, and it's my first brochure ever.

                 

                When you scale in InDesign the image pixels are resized not resampled—pixels are not added or subtracted from the image. If you scale an image to 50%, the image pixels get scaled to half their original size and you have effectively doubled the output resolution. The scaled resolution is also called Effective resolution and you can read that resolution in the Info or Links panels when the image is selected.

                 

                The scale amount only matters if it causes the effective resolution to drop below the requirements of the printing process. If the starting (Actual) resolution of the image is high enough there's no problem with scaling up— an image with an Actual resolution of 1000ppi could be scaled up to 300% and the Effective resolution would be 333ppi, more than enough resolution for most printing conditions.

                1 person found this helpful
                • 5. Re: Best way to scale down big images
                  Abambo Level 4

                  Q1: Don't worry, you need to take care of pictures that are (too) low resolution.

                  Link info gives that information with effective PPI. Actual PPI is what is written in the file exif data. You can ignore that (at least for now). Effective PPI should be more then 240ppi. During the PDF export the export procedure will resample to a lower value if the value is too high. Indesign does not resample, but adjusts only the output size (in inch or cm) according your frame and the image size in the frame. The PPI value moves up in this scenario, when you make your image (visually) smaller, or moves down when you make it bigger.

                   

                  Additionally, you have the image frame, which determines the visual limits of the image and the image itself. You can adjust the image to the frame by fitting in different manners:

                  I do the following: Fill Frame Proportionally. After hat I adjust my image in the frame to show the framing I want to show. You see the 2 circles in the image. That handle allows to select the image and to move and size the image according your needs inside of the frame .

                   

                  Q2: The final output will not be effected. Assigning a graphics frame does change how you can interact with the frame. No big deal, you can reverse your decision if needed. I do not consider this when starting to work.

                   

                  Q3: It is important to keep a consistent colour space, but if you have pictures in one colour space keep it there as long as there is no obvious reason to change. Your colour space workflow should be adapted to your output intent. For me it's European Prepress. CMYK conversion should be delayed. I create export with PDF X/4 standard. I get my print ready file that I send over to the print service provider. With Acrobat (DC) Pro, I check my file, but depending on the service provider (discount or standard print shop) I get informed on potential problems with the file. Important is, that you use the export feature and create a PDF file instead of using the print function, even if you print locally.

                  1 person found this helpful
                  • 6. Re: Best way to scale down big images
                    badpixxxel Level 1

                    Thank you Derek, now I realize I was worrying for no reason... I thought scaling down the images to around 15% of original size followed by the increase of dpi way over 300 will harm the image quality (something like "crowding" the pixels too much). I was wrong, thank you for your help.

                    • 7. Re: Best way to scale down big images
                      badpixxxel Level 1

                      Thank you rob for explaining what happens when you scale down images in ID and for reassuring me I'll have no problems when printing those big resolution images images into small frames.

                      • 8. Re: Best way to scale down big images
                        badpixxxel Level 1

                        Thank you too Abambo for the long and detailed answer. I didn't know there's a "Link Info" option, I only used "Info" but now it's much easier to check the images and their properties.

                        • 9. Re: Best way to scale down big images
                          badpixxxel Level 1

                          Thank you all for your answers. It helped me a lot to understand what I need to do next.

                          • 10. Re: Best way to scale down big images
                            Abambo Level 4

                            You're welcome!