CREAS consists mainly of two circuit blocks. The "HD Reality Enhancer" in the first block stresses the outline (sharpness) and enhances color gradation (smoothing) of 8-bit video signals that are input. It analyzes color information of hundreds of surrounding pixels and determines the intensity of sharpness and smoothing processing by each pixel.
"When the edges of the surrounding pixels are strong, for example, it mildly processes sharpness," a Sony spokesperson said. Internal computing is performed on 14-bit or higher quality video, and 14-bit video signals (YUV4:4:4) are output to the circuit in the second block.
The "Super Bit Mapping for Video" circuit in the second block works to convert the 14-bit video signals to 12- to 8-bit signals in accordance with the feature of the panel, on which the video is output. During the process, the circuit slightly increases amplitude of color signals so neutral colors can be rendered to reproduce 14-bit equivalent video even if it is output on a display that can only render 8- or 10-bit video.
The technique is similar to dithering as a signal processing, but Super Bit Mapping "increases amplitude at high space frequencies in an effort not to cause the processing to appear as noises, in consideration of characteristics of human vision," the spokesperson said.
http://techon.nikkeibp.co.jp/english/NEWS_EN/20080905/157531/