5 Replies Latest reply on Oct 3, 2012 8:06 AM by TLL...

    Enlarge image 800%

    RuneEilertsen Level 1

      Hi!

      I've got a hi-res tiff image (5031x3579 px) which I need to use as a background on a very large print (2500 mm x2500 mm, 300 dpi). I placed the original image in InDesign and had to enlarge it by approx 800% to fit the canvas. Effective dpi ended up at 35dpi. This, no suprise, looks **** when viewed at 50-100%, so I thought maybe it would be better to resize the image in photoshop before placing it in InDesign. Well, I did do that and ended up with an image with a huge filesize (2,5 Gb) before saving it as a tiff again. I noticed that many of the save as options didn't come up, only tiff, Large image format and native PS. I still dont know what the final file size will be... still waiting for it to finish processing.

       

      The method I used for enlargement was: Image size -> resample - bicubic smoother (best for enlargement) - in three steps, 200% up - 200% up - 150% up.

       

      What I'm asking for, is advice on how to deal with this problem the best way using photoshop CS6? I know I will loose quality, but want to minimize the appearant loss the best way.

       

      Thanks

       

      Rune

        • 1. Re: Enlarge image 800%
          c.pfaffenbichler Level 8

          The method I used for enlargement was: Image size -> resample - bicubic smoother (best for enlargement) - in three steps, 200% up - 200% up - 150% up.

          Why did you do that?

          Incremental upsizing in Photoshop is an obsolete technique.

           

          For products that size about 72ppi usually suffices in my experience.

          Has the printer expressly demanded 300ppi effective resolution?

          • 2. Re: Enlarge image 800%
            RuneEilertsen Level 1

            Hi!

            Yes, the specs I got from the printer says 300 dpi. I totally agree with you that 300 is a bit overkill on prints this size, considering the viewing distance.

             

            I have no good reason for doing what I did, just trying out stuff. I did however end up with a better image, compared to the enlargement done within InDesign.

             

            What would be the best way to enlarge this image, if the printer accepts 72 dpi resolution? The original image is 300 dpi.

             

            Rune

            • 3. Re: Enlarge image 800%
              Noel Carboni Level 8

              When you "viewed at 100%" and the "image looked ****" to you, was it just fuzzy or was it pixelated (visibly made up of colored squares)?

               

              If the former (fuzzy) is what you saw, your only recourse to not have it "look ****" is to either start with a higher resolution image or to use a more sophisticated upsampling technique, such as provided by OnOne Software's Perfect Resize 7 or Alien Skin's Blow Up 3.

               

              If it's pixelated by the resize option in InDesign, are you sure there are no options there that will do an interpolated (e.g., Bicubic) upsample instead of a pixelated (Nearest Neighbor) resize?

               

              Did you TRY printing a small portion of the image (e.g., on your local inkjet) to see how the print would actually look?

               

              -Noel

              • 4. Re: Enlarge image 800%
                c.pfaffenbichler Level 8

                I do not contest that upsampling in Photoshop gets better results, but I’d just do it in one step and then maybe sharpen the image (and possibly add some noise).

                • 5. Re: Enlarge image 800%
                  TLL... Level 3

                  I use Perfect Resize a lot and it works well. 8x should be doable but sucess will depend on original image quality, subject matter and practical considerations like viewing distance...