That’s right conclusions, not conclusion. There were many things to take away from theses tests. First, as was stated in the introduction, no upresing algorithm can match actual 4K footage. And generally that held true with the exception that out-of-focus areas and other areas of low detail can look the same when upresed. Of course, no film is going to be made of just these types of images so upresing just can’t match 4K overall. But that’s not what this test was about, we’re here to find the best upres solution.
Before we get to that though, it’s worth noting that it’s extremely difficult to quantify the subjective differences between all the algorithms tested. While most of the premium algorithms claim to be industry-leading or best in the industry when it comes down to it they’re very difficult to tell apart. It may be easiest to group and review similar algorithms:
The basic level
The general algorithms like bilinear and bicubic sampling can be found in nearly all software packages. If the sampling method is not listed, there is a high likelyhood that one of these two are being used. And if you have a choice, as you do in After Effects, bicubic does give slightly better results by reducing the amount of artifacts present. Utimately, though, these algorithms are the blurriest tested.
After Effects Detail Preserving Upscale
This one gets a category all it’s own. While it produced some surprisingly smooth results it also happened to completely smooth away all the grain in the image. It’s sort of a detail destroying upscale. Yes, there are adjustable settings within the plugin that can limit this effect, but it’s still present even at the highest levels. This leads me to think that this might have some artistic uses, but not for upresing filmed content. Also, we didn’t have a way to show it in the still images but this algorithm also introduces temporal artifacts due to small image changes leading to vastly different upres results. This leads to some flickering around edges.
The Pro Level
Pro as in professional and pro as in proprietary. In general Boris’ UpRez, Red Giant’s Instant 4K, MTI Cortex, and DVO Upscale perform very similarly. They all are better than the basic algorithms but not by huge leaps, and most provide some level of adjustment over sharpening. While we didn’t adjust each one for each shot for best results that would be the recommended workflow.
Cinnafilm Dark Energy Plugin
Dark Energy Plugin from Cinnafilm takes an interesting approach. The upscaling of image details would put it among the pro-level solutions, being better than bicubic but not by a wide margin. However, Dark Energy does something different than the rest when it comes to the grain of the image. It strips away the 2K-scale grain before upresing, then adds 4K-scale grain back into the image. This has the effect fooling the eye into thinking that it’s looking at higher resolution content. The smallest discernible detail clues our brain to how sharp an image is and with 4K-scale grain we get a feeling that we’re looking at 4K content.
This isn’t meant to be a review of each of the plug-ins and software packages. In fact, other than offering upres capabilities many of the host applications have little other overlap in what they offer. For that reason and many others it’s impossible to always suggest one solution over another. In terms of visual quality our favorite is Dark Energy. The sharper film-like grain really puts it over the edge. But that may not be your only deciding factor if you’re also looking for a transcoding, or grading, or dailies processing solution. For a single upres job you’re probably going to stick with the solution at hand, but if 4K upressing is going to become part of your workflow we hope you find this shootout a useful resource to inform a solution.