ASCII.jp Upscaler that can be used even for games that do not support DLSS, NVIDIA Image Scaling Bulletin Review! What is the difference from DLSS and FSR?

Release of NVIDIA Image Scaling, an upscaler that does not require support from the game side

When it comes to the comfort level of PC games, the first thing that comes to mind is the "frame rate". A smooth and stutter-free game screen is not only comfortable to play, but it is also an essential factor for winning in highly competitive games.

However, there are gamers who are not satisfied with just the frame rate. In order to fully enjoy the charm of the world and characters that the game is trying to express, the element of image quality (including resolution) cannot be neglected.

However, image quality and frame rate are always in a trade-off relationship. Where to distribute the limited GPU power and where to balance is a source of trouble. Especially now that video cards have risen in price, it is difficult to replace them with a higher-end GPU. It's only natural that you want to do something with the technology you have now.

　In recent years, "upscaler" technology has been attracting attention in order to make the most of the limited GPU power while balancing the frame rate and image quality. The game screen is rendered at a low resolution, and then output after super-resolution processing with an upscaler, so GPU power (and VRAM resources) can be used more effectively. The pioneer of this technology is NVIDIA's "DLSS (Deep Learning Super Sampling)", and AMD's "FSR (FidelityFX Super Resolution)" is also classified as this.

　The introduction has become long, but the other day NVIDIA held a briefing for the press and announced their new upscaler "NVIDIA Image Scaling". Let's briefly explain what is different from DLSS and FSR and what advantages they have.

Works with GeForce GTX 750 & 496.70 drivers or later, and in principle no support on the game side is required

　NVIDIA Image Scaling supports GeForce Game Ready Driver 496.70 or later and GeForce GTX 900 series (Maxwell generation GTX 750 /750 Ti is also included) and later. On the screen that will be explained from now on, it is written as image scaling, but it is difficult to distinguish whether this is the name of the technique or NVIDIA's technology. In this paper, NVIDIA Image Scaling will be abbreviated as “NIS”.

　NIS's greatest feature is that it does not require any support from the game side, and is a function that operates at the driver level. Existing DLSS and FSR could not be used if the game did not support them, but NIS does not even need it. Users just need to enable it in the NVIDIA Control Panel or GeForce Experience. The API works with DirectX 9 or later, as well as Vulkan and OpenGL.

When you open "Manage 3D Settings" in the NVIDIA Control Panel, there is an item called "Image Scaling". Turn this on first. The "sharpening" slider determines the degree of sharpness processing, and moving it to the right makes the blurring effect when upscaling less noticeable. Before you get used to it, let's check the "overlay indicator"

Click the gear icon in GeForce Experience and turn on (green) the switch to the right of Image Scaling. The rendering resolution shown here is for collective setting for all games. The meaning of the sharpening slider is the same as the one in the NVIDIA control panel

When you change the setting of NIS in GeForce Experience, a message like this appears at the bottom of the screen. The message is cut off, but clicking "optimize" will change the settings of all games that are already recognized by GeForce Experience, so I don't recommend it (it would be better if the fine print wasn't cut off. God is in the details. is)

After enabling NIS, either on GeForce Experience or by launching the game and setting the resolution lower than the physical resolution, you're done. If the game side is set to full HD in a 4K display environment, the screen output will remain a 4K signal and only the rendering will be full HD. Unlike DLSS, there is no particular lower limit, but if you lower it too much, the screen will naturally become rough

If the indicator is turned on, "NIS" will be displayed in green at the top left of the screen if NIS is working. If NIS is displayed in blue, only sharpness is effective, and if NIS is not displayed, neither is effective

If you run the game in windowed mode, select Scaled Resolution in the NVIDIA Control Panel. For example, if you select 2560x1440 dots scaled in a 4K display environment, the screen signal remains 4K, but Windows outputs the screen with the intention of 2560x1440 dots.

If the overlay is enabled in GeForce Experience, you can adjust the amount of sharpness by pressing Alt+F3 in-game.

As you can see, NIS does not need to be handled by the game side, but there are games that are not effective. This applies to games that do not use exclusive full screen mode even in full screen, and recent games such as "DIRT 5" and "Cyberpunk 2077" where the output signal to the display does not change even if the resolution is changed. NIS doesn't work in these games, and only sharpness processing is applied only when displayed in dot size.

　As you can imagine from the interface of the NVIDIA control panel, NIS is a technology that extends the existing "NVIDIA Image Sharpening". And most interestingly, NIS, like its rival FSR, is "open source," and NVIDIA claims it "works with all modern GPUs, including home consoles."

　However, it seems to contradict the phrase "all modern GPUs" when GeForce Experience and the NVIDIA control panel are required for setup, but the NIS SDK is an open source project on GitHub. Since it will be open to the public, it is not a lie that it is possible to port it to a home game machine and run it. Although the specific name was withheld, it is said that some game developers (of games for home game consoles) are actually showing interest.

Then, what is the difference between NIS and FSR... but first, please take a look at this document.

Quoted from NVIDIA documentation. NIS performs Spatial Upscaling and sharpening in a single pass. Anti-aliased and tone-mapped video is input and incorporated before post-processing. I feel like I've seen this picture somewhere...

That's right. The NIS processing pipeline is almost identical to that of AMD's FSR. Although the implementation of the core part differs between the two, it can be said that they are extremely similar.

　As you can see from the diagram above, the NIS processing pipeline is almost the same as AMD's FSR. FSR requires support from the game side, but there is no need to change the resolution of the game side. On the other hand, NIS needs to change the resolution on the game side, although the game side does not need to respond in principle. FSR's game side support is thought to be for adding a UI that allows you to select presets such as "balance" and "quality" and for hiding the internal resolution change from the UI. NIS can be said to be a solution that skips UI correspondence and seeks practical benefits.

　Current NIS has limitations. The first is the issue of screen capture. If you actually set the display to 4K and the game resolution to WQHD and take a screenshot, the resulting image will be WQHD. In my environment, the same is true when recording with OBS Studio's "Game Capture" behind the game, and problems such as only a reduced image can be obtained or the OBS side cannot detect it well (OBS's "screen Capture" can be captured without problems).

　The resolution of what is captured is a specification issue of NIS (because it is scaled at the kernel level), and it is necessary to go through a capture unit/card connected to another PC in order to preserve the correct resolution. In addition, NVIDIA's recording function "ShadowPlay" is waiting for future support.