Abstract: A method and system for automated video quality assessment which reduces the adverse effects of sub-field/frame misalignments between the reference and test sequences. More particularly, the invention provides for misalignments down to a sub-field/frame level to be handled by individually matching sub-field/frame elements of a test video field/frame with sub-field/frame elements from a reference video field/frame. The use of a matching element size that is significantly smaller than the video field/frame size enables transient sub-field/frame misalignments to be effectively tracked.

Abstract: A method and system for encoding a video signal provides an encoded signal that is compressed in order that it may be efficiently transmitted over the link whilst also meeting a predetermined standard in terms of its estimated perceptual quality when the signal is decoded and displayed. This is achieved by providing, at the encoding end, a control unit (24) which utilises a perceptual quality metric (PQM) system (32) to quantify the estimated perceptual quality, and control logic (34) that compares said quantified PQM with a user-defined criterion that the signal must meet prior to transmission. The signal is preferably only transmitted onwards over the communications link if the criterion is met. Otherwise, the control unit (24) is operable either to modify the signal, e.g. using pre-filtering, or use modified encoding parameters to re-encode the signal in such a way as to improve its quality, that is to make the quantified PQM converge towards the criterion.

Abstract: The quality of audiovisual material is assessed by measuring the audio an video quality and computing from these a combined measure. Using a parameter indicative of the degree of motion represented by the video, the computation employs one of a plurality of algorithms selected in dependence on the value of the parameter.

Abstract: The quality of audiovisual material is assessed by measuring the audio and video quality and computing from these a combined measure. Using a parameter indicative of the degree of motion represented by the video, the computation employs one of a plurality of algorithms selected in dependence on the value of the parameter.