5 Replies Latest reply on May 9, 2011 2:11 PM by areohbee

    Aliasing issues in ACR 6.4 output, jagged edges


      In images with high frequency detail, aliasing occurs that is most visible in diagonal directions. These jagged edges are noticable in the output, and obviously get worse in enlargements which is also the main reason I post this.


      To date, I've found 2 workarounds:

      1. process in ACR, duplicate layer in Photoshop, apply gaussian blur around 0,5px, and manually paint on the offending jagged edges
      2. use another raw converter


      For demonstration purposes, I've taken an old and unspectacular D3X NEF from imaging-resource.com. It's a picture of a house and some trees etc. I've used:

      1. Camera Raw 6.4 with default settings (first row): aliased edges
      2. Capture One Pro 6.2 with default settings (middle row): anti-aliased edges but introduction of false (green) colour
      3. Raw Developer 1.9.1 with default settings (bottom row): anti-aliased edges free from artifacts

      Some (100%)  area's where the aliasing shows:


      At first I thought the difference was due to the sharpening in these 3 convertors. Forgive me if I omit showing a comparison and just assert that turning of sharpening and replacing it with Photoshop remove lens blur, didn't help. It just showed the defects apparantly already present in the (ACR and C1 processed) file.


      The result however from a properly sharpened, denoised, and upsampled TIFF that originates from Raw Developer is impressive. However, given the fact that Raw Developer is Apple OSX only, and I do post-processing on Windows, it introduces a bit of an unpracticality.


      Is there any possibility to eliminate this unpleasant aliasing in ACR, so I can keep a high quality Adobe-only workflow?

        • 1. Re: Aliasing issues in ACR 6.4 output, jagged edges
          Noel Carboni Level 8

          The "blocky" details are easily reproduced in that image.  Looks like something that needs to be tuned up to me.




          Note that you have the option of choosing the 2003 process in Camera Raw, which appears to avoid that issue.




          I just want to add one thing:  There's no upsampled resolution available for this particular camera.  6048 x 4032 is the largest size available.  I for one prefer to convert my raw files directly to upsampled resolutions on the theory that it might improve this kind of thing (and it does seem to deliever more accurate detail with my now out-of-date Canon cameras).  At some point in the past I requested that Camera Raw make several upsampled resolutions available beyond the "native" camera size for any/all cameras.  I hereby renew that request.



          • 2. Re: Aliasing issues in ACR 6.4 output, jagged edges
            Vit Novak Level 3

            As I said several months ago, 2003 is better than 2010 in some respects ...

            • 3. Re: Aliasing issues in ACR 6.4 output, jagged edges
              JFNL Level 1

              Ah yes thank you both!


              It seems a compromise and layer mask painting are inevitable:

              • sharpening after using the 2003 process
              • blurring after using the 2010 process
              • 4. Re: Aliasing issues in ACR 6.4 output, jagged edges
                Noel Carboni Level 8

                I just wanted to add that I don't think this behavior is consistent with files from all cameras.


                I never see it in my Canon files as far as I can tell.



                • 5. Re: Aliasing issues in ACR 6.4 output, jagged edges
                  areohbee Level 6

                  Yep. PV2010 has a tendency toward the jaggies, worsened by sharpening. I sometimes use PV2003 on selected photos too. Or, selectively de-sharpen critical areas when using PV2010. PV2010 Color NR also eats up more dark tones than PV2003, so I have used PV2003 instead on some photos that have critical darks to preserve. Both of these issues were discussed at some length when PV2010 beta was first released, so Adobe knows about them.


                  I think PV2010 is excellent in most ways, but its not perfect, and is not even the best choice for all photos. The shrewd Lr-photographer learns its weaknesses and work-arounds...


                  I think Adobe said next PV will be circa 2017, but maybe that does not necessarily mean they won't slip a tweak or two in before then...