5 Replies Latest reply on Jan 3, 2012 10:21 AM by Jim Curtis

    How to Scale a Video Clip and Avoid Image Degradation?

    Shameless008

      Hi, I am trying to determine the best way to scale up a number of video clips in my sequence, so that I can "digitally zoom in" on the action, and yet hopefully avoid degradation of image focus/sharpness.

       

      My concern is that by using the Scale up Effect, it is distorting the images, i.e. stretching the pixels.

      (one of the clips I have tried using the Scale Effect on appears fuzzier and distorted, but it could've been an autofocus problem, I'm not sure).

       

      Here are the specifics of my setup.

       

      I am running PP CS5.5 on Windows 7, and I have an Nvidia CUDA card.

       

      I shot the video on a Canon Vixia HF/S21 in 1920x1080p at 24MBps (Canon calls this MXP, and the "p" is not native, it is "pulldown" inside the camera).

       

      My output will be h.264 for the web. I am fine with the output dimensions being 1280x720. The output does not have to be 1920x1080, BUT it would be nice IF I could output at 1920x1080  while keeping the picture crisp and sharp. If 1280x720 yields better results then I will do that.

       

      So my questions are the following:

       

      1) Does Using the PPCS5.5 Scale Effect cause a distortion of the image?

      - Does it cause the image to get fuzzy, less sharp/crisp?

      - (I am scaling the clips 50-70%)

       

      2) Is there any benefit to setting the Sequence Settings to 1280x720 (instead of matching the clips at 1920x1080)?

      - My thinking is to set the Sequence Setting to these Lower Resolution Dimensions and the I can get a 50% scale up by simply *not* using "Scale to Frame" on the clips I want 50% scaled up.

        • 1. Re: How to Scale a Video Clip and Avoid Image Degradation?
          Jim_Simon Level 8

          You can't increase the scale on a video frame without introducing some degradation.  You can often scale it down with minimal loss, but going up is generally best avoided.

           

          On a side note, both 50% and 70% are scaled down (made smaller).  It'd be 150% to scale it up (made larger).

          1 person found this helpful
          • 2. Re: How to Scale a Video Clip and Avoid Image Degradation?
            shooternz Level 6

            Absolutely you can edit your source footage in a sequence of lesser dimension and do your scaling up  to 100% of the original source footage dimension.

             

            Why did you not try that?  (You seemed to understand that concept)

             

            If you scale above your source dimension...expect degradation.

            1 person found this helpful
            • 3. Re: How to Scale a Video Clip and Avoid Image Degradation?
              Shameless008 Level 1

              Thanks Jim, I suspected that scaling up would introduce some degradation. (and you're right I did mean 150%).

              • 4. Re: How to Scale a Video Clip and Avoid Image Degradation?
                Shameless008 Level 1

                Thanks for thereply shooternz.

                 

                I did try this, but I wasn't certain if it was an improvement or not as I still some some out of focus areas in the video clip. Those may have been caused by the autofocus I used during shooting catching at different part of the action right at the same moment as where I split the clip for the zoom effect.

                • 5. Re: How to Scale a Video Clip and Avoid Image Degradation?
                  Jim Curtis Level 3

                  If you shot 1080, but you finish 720, that will allow you some flexibility to scale.  Pr calculates scale in two ways, which is very confusing.  If you set your sequence to 720, and your preferences to Default Scale to Frame Size, all the 1080 clips you add later will show 100% in the Effects Control > Motion tab, even though Pr has scaled your 1080 footage to about 45% to fit the 720 frame.

                   

                  I suggest you DEselect Default Scale to Frame Size.  Then, when you add your 1080 footage to your 720 sequence, it will be scaled at 100% (for real) and it will be larger than your 720 raster.  Only by doing this will you know whether you have scaled your footage beyond 100% when you're panning and scanning afterwards.

                   

                  Scale your first clip to fit the sequence, copy it, and use Paste Attributes on the rest of your 1080 clips to get them to scale down to fit the 720 raster.  Then you can make adjustments from there.

                   

                  BTW, there's an article on the Adobe site about how CUDA scaling is superior to Ps and Ae scaling.  Maybe somebody can find the link, or you can search the site for it.