NVIDIA DLSS 2.5.1 first appeared in the latest patch for Portal RTX released last week. After the festivities, it is now found that this latest version of the software does not have any built-in sharpening filter anymore. Advanced users have been using alternative methods (such as hex mods or DLSS SDK .dll, which, however, added a watermark) to fix sharpening issues in specific games, such as Red Dead Redemption 2 or God of War. The problems were most noticeable while in motion.
The news was confirmed by NVIDIA RTX Unreal Engine evangelist Richard Cowgill (father uploader on Reddit) with the following messages. It seems that NVIDIA is recommending that game developers use NVIDIA Image Scaling Sharing going forward.
Yes, DLSS sharpening is now deprecated in NVIDIA DLSS 2.5.1. We recommend developers use NIS sharpening (Nvidia Image Scaler) instead. NIS has arguably superior honing technology and can also provide cross-platform and non-RTX hardware backup for upgrading.
The latest DLSS does not use the old DLSS sharpening method anymore. We recommend that developers use NIS sharpening instead when implementing DLSS. This should result in better image quality.
NVIDIA Image Scaling (NIS) was released in November 2021 as an upgrade to its previous image scaling technology. The new algorithm uses a 6-click filter with 4 directional scales and adaptive sharpening filters. Scaling and sharpening also happen in a single pass, which boosts performance.
NVIDIA Image Scaling works with GPUs from all vendors (including AMD and Intel) and is open source. Game developers interested in adding NIS to their games can download the latest version of the SDK from GitHub.
If you’re interested in reviewing the unoptimized upgrade results available with NVIDIA DLSS 2.5.1, you’ll either have to download the latest .dll from TechPowerUp and manually insert the file into the game of your choice or use the handy DLSS Swapper tool from Australian programmer Brad Moore.