Morphological antialiasing (MLAA) is a technique for minimizing the distortion artifacts known as aliasing when representing a high-resolution image at a lower resolution.
Contrary to multisample anti-aliasing (MSAA), which does not work for deferred rendering, MLAA is a post-process filtering which detects borders in the resulting image and then finds specific patterns in these. Anti-aliasing is achieved by blending pixels in these borders, according to the pattern they belong to and their position within the pattern.[1][2][3]
Enhanced subpixel morphological antialiasing, or SMAA, is an image-based GPU-based implementation of MLAA[4] developed by Universidad de Zaragoza and Crytek.[5]