Upscaling Filters

Upscaling Filters

The 3DS screen is small (400×240 top, 320×240 bottom). Stretched onto a big monitor it looks blurry or jagged. The Upscale dropdown in the stream control bar applies a real-time GPU filter that sharpens and cleans the picture as it's scaled up.

These are faithful ports of well-known GPU shaders to 3DSnickerStream's rendering engine — no external dependencies, still a single portable download. Everything runs on your PC's GPU (the stream itself still comes from the 3DS exactly as before). If your machine has no usable GPU, the filters fall back to a CPU implementation.

The filters

Filter	What it does	Best for
None	no filter (the interpolation from the Filter dropdown still applies)	—
Sharp	crisp nearest scaling + a light clamped sharpen	a fast, general "harder" look
xBR	Hyllian's xBR-lv2 — edge-directed interpolation, smooth clean diagonals	2D pixel art
Super-xBR	the same engine tuned for anti-aliased (softer) edges	2D pixel art
ScaleFX	Sp00kyFox's ScaleFX — the reference pixel-art upscaler, the smoothest edges of all	2D pixel art
FSR	AMD FidelityFX-style edge-adaptive upscale + sharpen	3D games
Anime4K	smooth base + strong line-art sharpening	cel-shaded / anime-style
Anime4K CNN	a small neural network (bloc97's Anime4K CNN) running live on the GPU	a learned upscale to try

Which should I use?

• 2D / pixel-art games → xBR, Super-xBR or ScaleFX. These are edge-directed: they turn the staircase on diagonal lines into smooth, clean edges while keeping the art crisp. ScaleFX is the highest quality; xBR is the classic emulator look.
• 3D games → FSR (edge-directed pixel-art filters have little to work with on 3D/gradient content).
• Just want it sharper → Sharp.
• Experiment → Anime4K CNN is a genuine neural upscaler; it's tuned for anime video, so on pixel art it behaves more like a smart sharpen than an edge smoother — fun to compare.

Tips

• Pair pixel-art filters with a Lossless compression mode. xBR / Super-xBR / ScaleFX key off clean pixel edges. JPEG compression adds ringing that can make them look "oily". A Lossless (Reliable Stream) mode (see Compression Formats) gives them a perfect source — see the difference.
• The Upscale filter (the algorithm) and the Filter dropdown (final interpolation: Sharp / Linear / Smooth) are independent and stack.
• On a low-power or GPU-less machine, the multi-pass filters (ScaleFX, Anime4K CNN) fall back to the CPU.

Requirements

A GPU is recommended for the multi-pass filters (ScaleFX, Anime4K CNN) to run at full speed; the single-pass filters are cheap on any modern hardware.

Credits

xBR by Hyllian and ScaleFX by Sp00kyFox (from the libretro shader collection), Anime4K by bloc97, and FSR by AMD (FidelityFX). Thank you.