Upscaling to 4k ¿Before or after post?

Started by futografia, February 13, 2017, 04:57:09 PM

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futografia

Since raw video could be less compressed by vimeo/youtube when upscaled to 4K.

In which part of the process should I upscale? Before edit, grading or just before uploading? Does it makes any difference?

Thanks

hyalinejim

Save yourself a headache and upscale as the last step before export.

bpv5P

The best result will probably be if you apply your noise reduction (if needed) first, then upscale to just after that start grading/sharpening.
But it will significantly increase the computational power.

justinbacle

I do all my post prod in the native resolution (1280x1056 in my case, for 2.4:1 anamorphic) and do the final export in the wanted resolutions. I usually export :
- a "master" file in Cineform 10b 422 in native resolution
- a 4K youtube export (from the Master file)
- a 1080p youtube export (from the Master file)

I found thart by keeping the same resolution in the entire process saves me the headache of choosing a different format for each intermediate file (as Cineform has no resolution restrictions were DNxHD is limited to "well-known" resolutions)

Lars Steenhoff

for the best results do the upscale in the raw conversion ( debayer to 4k directly), because the sharpening that you apply there can be tweaked to look best for 4k.

dfort

You should upscale before buying the camera.

dariSSight

@Lars Steenhoff @dfort With all the video production intelligence on Magic Lantern forum we never get a objective analyzation of upscale from a 36x24 Full Frame sensor RAW to 2K or 4K or at least percentage safe zones for upscaling. Is there any way we can get an objective opinions on upscaling RAW?
Canon 5D Mark II

Lars Steenhoff

@dariSSight  You mean like to make a test ?

one with 4k output in the debayer and one with upscale after the debayer?

dfort

Of course I was just kidding on that last comment I made. One thing is theory and another is what usually happens in real life. I work in post production and have been involved on a few projects where we had to upscale. It was always done as the last step not because that's the best place to do it but because the costs to go back and upscale the original media is too great to justify any minor improvement you might gain. Note that the upscaling algorithms seem to keep getting better as the demand to deliver 4k content increases.

However, we're talking about upscaling in the debayer stage? Can it be done by simply adjusting the metadata? How does that work? I heard that you can adjust the aspect ratio on a DNG but can you do that in the x and y axis to rescale the image?

dariSSight

Thanks for the response guys. I'm wondering if for example Adobe Camera RAW color correction Magic Lantern DNG via MLVFS open in Final Cut Pro X edit in Project export to 4K or Adobe Camera RAW color correction Magic Lantern DNG via MLVFS then export as 16bit TIFF as 4K, or Adobe Camera RAW color correction FCPX export/Adobe Camera RAW 16bit TIFF to favorable percentage upscale.
Canon 5D Mark II

Danne

QuoteI heard that you can adjust the aspect ratio on a DNG but can you do that in the x and y axis to rescale the image?
Not from what I tried here.
http://www.magiclantern.fm/forum/index.php?topic=13152.msg182009#msg182009