FrameFlex vs. Resize


Avid FrameFlex is a new feature in Media Composer v7 that allows for image re-framing. The FrameFlex parameters go back to the original high resolution master using more pixels to create the new frame rather than resizing an HD frame to the new size. One result involves more pixels being used and scaled down, versus the latter which takes pixels and blows them up. Scaling tends to result in a higher quality image compared to the reverse. So with this in mind, and knowing that only FrameFlex uses the original source file resolution, and any scaling operation that is not FrameFlex is restricted to the HD resolution of the project, I set out to compare the different methods of re-scaling versus extraction.

  1. FrameFlex
  2. 3D Warp Effect with HQ active
  3. Standard Resize effect 

The image above is a 4K (quad GD) R3D file. As you can see from the FrameFlex bounding box, it is a rather aggressive “punch-in” for the shot. In FrameFlex terms, it is 50%, as far as resize goes, it is 200%.  The results were really surprising. In the end, I did not see 200% of “wow” difference. For the most part, it was very difficult to see the differences between the two operations. While there is some very slight softening, it was not as much as I thought it was going to be. And just to be sure, I did the same extraction in RedCine X Pro to use as reference. In that frame there is a difference in the gray area of the shirt which could be attributed to the 12bit to 10 bit transcode. In all tests, the R3D was done as a FULL debayer to an uncompressed HD MXF file.

Here are the resulting frames exported as TIFF. Click links to download each file.

I also did a quick test with the standard Resize effect which does not have an HQ button and there is some very slight difference there, compared to the 3D Warp resize with HQ active. If you want to download the zip file with all the TIFF files, click here. In the end, it’s different tools for different jobs. The 3D Warp does give you extra image control such as rotation to level out a horizon when needed. 

Quality overall is difficult to tell from stills alone. Codec, aspect ratio (other than a multiple of 16:9) motion and other factors do come into play, but with all things relative, I was more surprised at how well the resize from HD stood up. Even the amount of detail and noise in a shot could affect the overall quality of the resize versus extraction operations. Here is a download of the same test with the XAVC 4K codec. In this case, the 3DWarp is less crips at the same 200% push, but as expected, with smaller push-in, it becomes less noticeable.  Also, there would be a distinct visible quality difference had the same re-frame was shot as Quad HD resolution to start with versus an extraction,  but that is a test for another day.

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