Pixel-perfect (integer) scaling —
testing with a non-computer video source:
SNES Mini game console (1280×720)
SNES Mini (Super Nintendo Classic) is the official retro game console from Nintendo that replicates (with emulation) the most advanced 16-bit console — Super Nintendo.
SNES Mini outputs 1280×720 (HD) via HDMI and has a pixel-perfect mode, but previously edges of pixels inevitably got blurry anyway on all 4K monitors and TVs due to blurry HD→4K scaling by the display itself.
Now with the Eve Spectrum 4K monitor and its “Pixel perfect” upscaling mode, we finally get perfectly sharp image with zero blur when using SNES Mini. And as long as the game does not need aspect-ratio correction and looks fine with square pixels (e.g. “Super Mario World” or “BlackThorne”), the resulting scaled image is also free of horizontal distortion / pixel shimmering. (SNES Mini’s 1280×720 output resolution is too low for pixel-perfect aspect-ratio correction with integer scales used both vertically and horizontally like e.g. bsnes-mt emulator does.)
720×480 instead of 1280×720 via HDMI port #2 [NEW 2021-07-21]
For some reason, SNES Mini output is displayed as 720×480 when the game console is connected to Eve Spectrum via the monitor’s HDMI port #2 instead of #1. So instead of being pixel-perfectly scaled to 4K, the image is blurry and smaller than it should be:
The photos below are taken with SNES Mini connected to Eve Spectrum via HDMI port #1 which is free of this issue.
As with the previous photo set, view full-size photos (not resized by web browser) to see a more detailed image.
SNES Mini user interface
Just in case, the “gear” icon is scaled unevenly by SNES Mini itself when the menu item is current. The monitor’s pixel-perfect scaling is 100% uniform.
Super Mario World
Classic Nintendo game and character.
The SNES version of this game has exactly the same graphics as its DOS version, but lacks original music. This game does not come with SNES Mini by default.
Donkey Kong Country
This game actually needs aspect-ratio correction for proper object proportions, so the image is slightly narrower horizontally than intended, but I still decided to provide a photo of a nostalgic scene in pixel-perfect mode.