2015-11-16, 07:26
3. Image Enhancements
Low Processing
enhance detail:
Doom9 Forum: Focuses on making faint image detail in flat areas more visible. It does not discriminate, so noise and grain may be sharpened as well. It does not enhance object edges but can work well with line sharpening algorithms to provide "complete" image sharpening.
LumaSharpen:
SweetFX WordPress: LumaSharpen works its magic by blurring the original pixel with the surrounding pixels and then subtracting the blur. The end result is similar to what would be seen after an image has been enhanced using the Unsharp Mask filter in GIMP or Photoshop. While a little sharpening might make the image appear better, more sharpening can make the image appear worse than the original by over-sharpening it. Experiment and apply in moderation.
Medium Processing
crispen edges:
Doom9 Forum: Focuses on making high-frequency edges crisper by adding light edge enhancement. The thin edge look should lead to an image that is more high-definition.
thin edges:
Doom9 Forum: Attempts to make edges, lines and even full image features thinner/smaller. This can be useful after large upscales, as these features tend to become fattened after upscaling. May be most useful for animated content and/or used in conjunction with SuperRes at low values.
sharpen edges:
Doom9 Forum: A line/edge sharpener similar to LumaSharpen and AdaptiveSharpen. Unlike these sharpeners, sharpen edges introduces less bloat and fat edges. More aggressive than crispen edges.
AdaptiveSharpen:
Doom9 Forum: Adaptively sharpen the image by sharpening more intensely near image edges and less intensely far from edges. The outer weights of the laplace matrix are variable to mitigate ringing on relative sharp edges and to provide more sharpening on wider and blurrier edges. The final stage is a soft limiter that confines overshoots based on local values.
General Usage of Image Enhancements:
Each sharpener serves a different purpose. It may be desirable to match an edge sharpener with a detail enhancer such as enhance detail. The two algorithms will sharpen the image from different perspectives, filling in the flat areas of an image as well as its angles. A good combination for 1080p content shown at 1080p might be:
sharpen edges (0.2)
enhance detail (0.5)
sharpen edges provides subtle line sharpening for an improved 3D look, while enhance detail brings out texture in the remaining image.
Low Processing
enhance detail:
Doom9 Forum: Focuses on making faint image detail in flat areas more visible. It does not discriminate, so noise and grain may be sharpened as well. It does not enhance object edges but can work well with line sharpening algorithms to provide "complete" image sharpening.
LumaSharpen:
SweetFX WordPress: LumaSharpen works its magic by blurring the original pixel with the surrounding pixels and then subtracting the blur. The end result is similar to what would be seen after an image has been enhanced using the Unsharp Mask filter in GIMP or Photoshop. While a little sharpening might make the image appear better, more sharpening can make the image appear worse than the original by over-sharpening it. Experiment and apply in moderation.
Medium Processing
crispen edges:
Doom9 Forum: Focuses on making high-frequency edges crisper by adding light edge enhancement. The thin edge look should lead to an image that is more high-definition.
thin edges:
Doom9 Forum: Attempts to make edges, lines and even full image features thinner/smaller. This can be useful after large upscales, as these features tend to become fattened after upscaling. May be most useful for animated content and/or used in conjunction with SuperRes at low values.
sharpen edges:
Doom9 Forum: A line/edge sharpener similar to LumaSharpen and AdaptiveSharpen. Unlike these sharpeners, sharpen edges introduces less bloat and fat edges. More aggressive than crispen edges.
AdaptiveSharpen:
Doom9 Forum: Adaptively sharpen the image by sharpening more intensely near image edges and less intensely far from edges. The outer weights of the laplace matrix are variable to mitigate ringing on relative sharp edges and to provide more sharpening on wider and blurrier edges. The final stage is a soft limiter that confines overshoots based on local values.
General Usage of Image Enhancements:
Each sharpener serves a different purpose. It may be desirable to match an edge sharpener with a detail enhancer such as enhance detail. The two algorithms will sharpen the image from different perspectives, filling in the flat areas of an image as well as its angles. A good combination for 1080p content shown at 1080p might be:
sharpen edges (0.2)
enhance detail (0.5)
sharpen edges provides subtle line sharpening for an improved 3D look, while enhance detail brings out texture in the remaining image.
