Perceptual compression

Perceptual processing is a form of video optimization that accounts for three types of typically disparate compression: spatial and temporal compression. Temporal compression is compression over time, and is widely used by a number of interframe compression standards, such as H.264 and H.625, to gain significant compression advantages by looking ahead from a keyframe (or I-frame) across a long group of pictures (GoP) and compressing only what changes on a temporal basis (known as P and B blames). Spatial is used to gain compression on an I-frame or even more rudimentary compressions such as JPEG for still images. Some forms of perceptual processing take into account the context of where the compressed video will be delivered (e.g., small screens on a smartphone over a cellular data network) while other forms of perceptual processing are aware of the types of content and assign processing based on more or less complex parts of a frame (or frames over time).