AMD FidelityFX Contrast Adaptive Sharpening (CAS) provides a mixed ability to sharpen and optionally scale an image. The algorithm adjusts the amount of sharpening per pixel to target an even level of sharpness across the image. Areas of the input image that are already sharp are sharpened less, while areas that lack detail are sharpened more. This allows for higher overall natural visual sharpness with fewer artifacts.

CAS was designed to help increase the quality of existing Temporal Anti-Aliasing (TAA) solutions. TAA often introduces a variable amount of blur due to temporal feedback. The adaptive sharpening provided by CAS is ideal to restore detail in images produced after TAA .

CAS’ optional scaling capability is designed to support Dynamic Resolution Scaling (DRS). DRS changes render resolution every frame, which requires scaling prior to compositing the fixed-resolution User Interface (UI). CAS supports both up-sampling and down-sampling in the same single pass that applies sharpening.