A study of subjective scores and objective algorithms

By Anush Krishna Moorthy and Alan Conrad Bovik
Laboratory for Image and Video Engineering (LIVE)
The University of Texas at Austin

With an increasing demand for entertainment and with the ever-improving technology to fuel this demand, the pervasiveness of digital video in everyday life cannot be debated. From entertainment on the move - hand-held phones spewing out videos - to entertainment at home, digital videos are everywhere. Moreover, wireless systems are rapidly replacing present-day wire-line systems, and new-generation encoders with tremendously improved compression efficiency are being standardized. In such an environment, a digital video passes through numerous processing stages before it finally reaches the end-user. The original video sequence at the transmitter end is passed through an encoder which compresses and restructures the video sequence, which is then passed over a channel. At the receiver end, a decoder decompresses the sequence into a format visible to the end user. Throughout this process, distortions are introduced in the video stream, which can produce visually annoying artifacts at the end-user. The encoder, the channel, the decoder and the display can introduce distortions in the video sequence.

Given that the ultimate receivers of wireless videos are usually human observers