Overview
Effects like unsharp mask are designed to sharpen or soften the image in a wider range, to enhance medium sized details in the image and give the content some grip. The balanced, yet contrasty look of movie posters and magazine covers is quite often partially achieved through this effect.
Much research is going into the type of filters that enhance local contrast, from the most basic unsharp mask to state of the art “Local Laplacian” filtering.
Using this effect in realtime on video games allows to give blurry textures some bite, enhance the overall contrast of a scene or produce some pseudo Depth of Field effect to give the scene some depth.
Clarity contains 2 different types of image enhancements, which we can use together, both adding and removing. Let’s look at each of them in detail.
Texture
Texture enhances small, high frequency detail by giving it more tonal range. Its influence is subtle yet effective and can be used to combat the overly blurry and hazy appearance that e.g. Temporal Anti Aliasing in newer games produces. It’s something you enable and forget about it, yet rub your eyes once it’s off.
Note how the edges of the objects are unaffected, yet the perceived clarity of the textures increases dramatically. Texture can also be removed from the image, which smoothens texture areas while leaving object outlines unaffected. This can be used to soften skin.
Local Contrast
Local Contrast brightens dark areas and tones down bright areas, depending on their relative darkness compared to surrounding scenes. This sets it apart from global contrast adjustments, which are agnostic to scene content. Adding local contrast visually flattens the image without affecting the object fidelity.
Local contrast can also be removed from the image. As a result, the image receives a contrasty yet bloomy look with deep shadows.
Depth Masking
Something that is usually manual (or AI-driven) work in editing software is separation by depth, driving the parameters by distance from the camera. With Clarity, this allows for easy foreground/background separation without using an intrusive effect like Depth of Field.
Just set your separation distance and tweak each of the effects above independently for foreground and background. Clarity interpolates smoothly in between.
In the title image of this post, Texture was used with +100% on foreground and -100% on background. As a result, the character appears much more in focus and gains presence in comparison to the background, which becomes subdued, yet without becoming visibly blurred.