DTD Shader
Anime4K_DarkLines + Anime4K_ThinLines + (Anime4K_Deblur or Anime4K_Upscale_Deblur)
Anime4K_Upscale_DTD_x2.glsl
Not a shader per-se, but a combination of three shaders. DTD is short for Darken-Thin-Deblur. It tries to restore perceptual quality of lines in blurry images by darkening lines, thinning them and then applying a deblur shader. This undoes what blur does to lines, since blur spreads lines out, thickens them and makes them lighter.
For blurry images, this shader restores perceptual quality better than deblur alone.
If we treat bilinear upscaling as a gaussian blur degradation, the DTD shader can be adjusted to upscale an image quickly with good perceptual quality.
See related shaders for settings and special considerations.
Line Thinning Shader
Line Darkening Shader
Deblur Shaders
Upscale Shaders