An example of an alternative approximation of an EOTF of a CRT display An example of an EOTF that has alternative characteristics of a CRT’s EOTF: for for where 0.35, 1 = 2.6, 2 = 3.0 Vc: Screen luminance (cd/m2) L: Screen luminance for white, reference setting is = 100 cd/m2 LW: LW Input video signal level (normalized, black at 0, to white at 1. 10-bit digital V: code values map into values of V per the following equation: “D” V = (D-64)/876) Coefficient for normalization (so that V = 1 gives white), (k = + k: LW/[1 b]1) Variable for level lift (legacy control). b: “brightness” The value of is set so that the calculated luminance can be the same as the b measurement data at input signal level 0.0183 (= (80-64)/876). The value of changes depending on control. b “brightness” 1 EOTFs: Black dot (measured data), Red line (reference EOTF), Blue line (alternative EOTF equation, Vc: 0.35, 1 = 2.6, 2 = 3.0) Appendix 2 (Informative) Historic overview CRT displays have been used as the reference display in HDTV programme production and monitoring for many years. Displays based on different physical technology are now being employed to replace the aging CRT displays. It is important to specify the characteristics for this next generation of display technologies so that consistent results may be achieved in future programme production. It is useful for the EOTF specified for the new display technologies to closely match the EOTF of the legacy CRT display. However, the legacy CRT EOTF was never documented, as all CRTs naturally behaved similarly. This Recommendation specifies a reference EOTF that should be employed in displays used in HDTV programme production. While the image capture process of Recommendation ITU-R BT.709 had an optical to electrical transfer function, there has never been an EOTF documented. This was due in part to the fact that display devices until recently were all CRT devices which had somewhat consistent characteristics device to device.
An example of an alternative approximation of an EOTF of a CRT display An example of an EOTF that has alternative characteristics of a CRT’s EOTF: for for where Vc: 0.35, 1 = 2.6, 2 = 3.0 L: Screen luminance (cd/m2) LW: Screen luminance for white, reference setting is LW = 100 cd/m2 V: Input video signal level (normalized, black at 0, to white at 1. 10-bit digital code values “D” map into values of V per the following equation: V = (D-64)/876) k: Coefficient for normalization (so that V = 1 gives white), (k = LW/[1 + b]1) b: Variable for level lift (legacy “brightness” control). The value of b is set so that the calculated luminance can be the same as the measurement data at input signal level 0.0183 (= (80-64)/876). The value of b changes depending on “brightness” control. 1 EOTFs: Black dot (measured data), Red line (reference EOTF), Blue line (alternative EOTF equation, Vc: 0.35, 1 = 2.6, 2 = 3.0) Appendix 2 (Informative) Historic overview CRT displays have been used as the reference display in HDTV programme production and monitoring for many years. Displays based on different physical technology are now being employed to replace the aging CRT displays. It is important to specify the characteristics for this next generation of display technologies so that consistent results may be achieved in future programme production. It is useful for the EOTF specified for the new display technologies to closely match the EOTF of the legacy CRT display. However, the legacy CRT EOTF was never documented, as all CRTs naturally behaved similarly. This Recommendation specifies a reference EOTF that should be employed in displays used in HDTV programme production. While the image capture process of Recommendation ITU-R BT.709 had an optical to electrical transfer function, there has never been an EOTF documented. This was due in part to the fact that display devices until recently were all CRT devices which had somewhat consistent characteristics device to device.
R-REC-BT.1886-0-201103-I!!MSW-E.docx