5 Replies Latest reply on Jun 24, 2012 7:52 AM by MadManChan2000

    Noise reduction for 32bit images acting totally different

    Joe_Mulleta

      The noise reduction behaves totally different when used for 32bit images in ACR.

      It appears like it is applying some kind of strange blur or glow effect instead of working like expected from 8/16bit material.

       

      Can anybody confirm this and is this intended behaviour?

        • 1. Re: Noise reduction for 32bit images acting totally different
          Noel Carboni Level 7

          Sorry for a naive question, but what file format are you using?

           

          I tried to reproduce what you're seeing, so I created a small document with some noise in it, converted to 32 bits/channel mode, and saved as a PSD.

           

          Camera Raw wouldn't open it...

           

          NoDice32Bit.jpg

           

          -Noel

          • 2. Re: Noise reduction for 32bit images acting totally different
            Jeff Schewe Level 5

            The 32 bit file must be saved as a TIFF, not PSD...

            • 3. Re: Noise reduction for 32bit images acting totally different
              Jeff Schewe Level 5

              Joe_Mulleta wrote:

               

              The noise reduction behaves totally different when used for 32bit images in ACR.

               

              How did you get your raws into HDR?

               

              Did you use raw files in ACR? Did you set the sharpening and noise reduction to optimal parameters in ACR on the raw files BEFORE going into HDR Pro?

               

              You should...I've found that it's important to optimize the raw files in ACR/LR before actually processing the raw files into HDR Pro...you need to realize that once the raw files are demosaiced, the best place to apply sharpening and noise reduction has been bypassed?

               

              Yes, a 32-bit TIFF opened in ACR 7.1 will not have the same sharpening and noise reduction opportunities once the original raw files have been processed. I've found it's useful to apply all ACR image optimizations (including tone, color and sharpening/noise reduction) to the raw files BEFORE doing a conversion to HDR Pro...

               

              And yes, the noise reduction settings in 32-bit in ACR 7.1 are _VERY_ tweaky (meaning you need to be very careful on the settings).

              • 4. Re: Noise reduction for 32bit images acting totally different
                Noel Carboni Level 7

                Jeff Schewe wrote:

                 

                The 32 bit file must be saved as a TIFF, not PSD...

                 

                Thank you.  And it must be opened with Camera Raw 7.1, not 7.0.

                 

                I just did a quick test and I found the noise reduction facilities to work as expected.  It was quite effective at reducing both color and luminance noise, per the settings I dialed-in.

                 

                Joe, is there something specific I should look for?  Can you do some screen grabs to show the difference with the particular image data  you're using?

                 

                -Noel

                • 5. Re: Noise reduction for 32bit images acting totally different
                  MadManChan2000 Adobe Employee

                  Currently the noise reduction on floating point images (including 32-bit TIFFs) in ACR 7.1 / LR 4.1 is more twiddly, because there is no noise profile data.  Effectively the NR methods can't assume anything about the noise content of the image (because it doesn't know "how" the image was merged), so the controls behave a bit more like they do for output referred images like JPEGs.  In other words, they have much larger range to deal with a larger possible set of noise conditions.  This is what makes them feel a bit more twiddly.

                   

                  This situation will likely improve in the future, but I can't specify more at this time.