From time to time, most editors have a need to upscale or uprez some of their video clips. It can be done in Vegas by simply rendering using a higher resolution template with/or without use of the Smart Upscale Fx. There are also many external open-source resizers that are available. The question becomes--how good is the upscaling? Most editors simply use the “eyeball” approach which is perfectly OK.
However, like render quality (RQ), some may want to see more evidence-based objective measures since “eyeballs” are known to differ dramatically. Here’s an approach that makes use of the RenderQuality tool that is freely available in the HappyOtterScripts Free Tools library. https://tools4vegas.com/library/
The idea is very simple. Here are the steps:
1. Begin with some “full” resolution video footage.
2. “Down rez” that footage to the same aspect ratio and frame rate using a high quality resizer--or any resizer for matter.
3. Then "upscale” the "down-rezzed" video to the original frame size, again keeping the same aspect ratio and frame rate.
4. Compare the quality of the original “full” resolution video footage with the “upscaled” video using the RQ tool.
5. For all renders, it is important to use a lossless codec such as MagicYUV, UtVideo or Uncompressed.
For the following tests, the footage I used may be downloaded here. https://www.dropbox.com/sh/8fzp947zo2eijnf/AADcbXXw5AxNYrCN96I2brvZa?dl=0
The original “out-of-the-camera” file is Butterfly.MTS which is FHD at 60P. The down-rezzed test file is UpRezTestClip.avi which is 854 x 480 at 60P. It was created using the Lanczos-4 resizer with MagicYUV RGB as the format. As you can see, there is a fair amount of motion content in the test video.
Here’s a demo of the procedure used for one of the conditions--a straight render from Vegas using an FHD render template.
Resizers included those available in HappyOtterScripts plus the “super-resolution” resizer that is available at http://www.infognition.com/. I should note that Video Enhancer which includes the “super-resolution” resizer is a standalone app that is now freeware. Moreover, the resizers used in HOS are also open-source and are freely available.
And here are the results which more or less speak for themselves.
From the results, the two Lanczos resizers resulted in the smallest error, although the Spline, Blackman, and SuperRes resizers were not far behind in terms of quality. Again, all of these are open-source and can be freely downloaded.
It should be pointed out that the Vegas Smart Upscale Fx should not be judged in terms of its error alone since I suspect that the Fx does some noise filtering and sharpening which would always increase the measured error regardless of the resizer being used. To judge its quality, one has to resort back to the “eyeball” method, which as I stated at the outset, is perfectly OK. The only truly valid results are the Vegas-480 and Vegas-1080 (different project frame sizes) which were identical as expected.
Comments are welcome.