Rec ITUR BT1691 1 RECOMMENDATION ITU‑R BT1691 Adaptive Image

rec. itu-r bt.1691 1 recommendation itu‑r bt.1691 adaptive image quality control in television systems (question itu-r 98/6) (200

Rec. ITU-R BT.1691 1
RECOMMENDATION ITU‑R BT.1691
Adaptive image quality control in television systems
(Question ITU-R 98/6)
(2004)
The ITU Radiocommunication Assembly,
considering
a) that digital TV systems have been developed as a compromise between
image quality and compression ratio with consideration of image
statistics, human visual perception, methods of image processing,
characteristics of transmission and receiving equipment, and capturing
and display systems;
b) that use of digital representation brings an opportunity to
transmit additional information inside the digital TV signal, the use
of which provides the possibility of control of video signal
processing characteristics at the transmitting and receiving ends;
c) that new methods of image processing and transmission, such as
fractal analysis, wavelet transformation, object-oriented coding,
transmission of content and corresponding tools, are now developed and
may be used in future TV applications, and that parameters and
characteristics of these methods may be controlled during video
transmission;
d) that an objective of television broadcasting is to obtain optimum
(for TV applications) subjective quality of the reproduced image for
any programme content, any type of image compression, any source and
reproducing devices, and any viewing conditions;
e) that the receiver of the future may contain adaptive processing
that can calculate necessary processing parameters for optimum image
quality;
f) that nominal parameters for image processing at the transmitting
and receiving ends may be generated at the transmitting end and
transmitted for use by image processing devices at the receiving end;
g) that an important part of adaptive image quality optimization is
colour reproduction quality optimization and that this specific matter
is a subject of Recommendation ITU‑R BT.1692;
h) that the new methods should be compatible with existing colour
transmission methods, so that future TV systems may operate at either
of two levels:
– non-adaptive TV systems (conventional TV systems);
– adaptive TV systems,
recommends
1 that in adaptive TV systems methods of global optimization of image
quality should be used, either by optimization of individual
parameters, or by optimization of grouped parameters;
2 that for image quality optimization, information is needed on the
characteristics of the transmitted image, on viewing conditions, on
transmission conditions, on the method of presentation, and on any
intermediate devices in the signal path which may affect the signal
quality. This information should be inserted in a defined location in
the bit stream so that it may be read by adaptive signal processing
devices at the transmitting and receiving ends;
3 that adaptive TV systems should be compatible with existing TV
systems.