Overview of ARIB Technical Report (TR-B9)
|TR Number||ARIB TR-B9|
|Technical Report Name||Guideline for Colorimetry for 1125/60 HDTV Production System|
The ITU-R BT.709-3 Part2 Colorimetry (“709” below) is applied to BTA S-001B “1125/60 HDTV Production Systems Standard” to which the effective line number of 1080 is added for program production of BS digital broadcasting.
The SMPTE 240 Colorimetry (“240M” below) is applied to studio apparatuses based on the effective line number of 1035 system and the ITU-R BT.601 Colorimetry (“601” below) is applied to studio apparatuses of the 525 system (525p, 525i).
The “709” is applied to the broadcasting using the MUSE system, and the BS digital broadcasting using the video input signals (1125i, 525p, 525i). The “601” is applied to the analog terrestrial broadcasting (525i) and the CS digital broadcasting (525p, 525i).
For studio apparatuses, 3 colorimetric parameters of “709”, “204M”, “601” are used with the 1125 system and the 525 system, and for broadcasting, “709” and “601” are used.
This technical report is established in order that program production is smoothly performed with multiple colorimetric parameters, and gives the points to be considered, for connections and operations of apparatuses and systems without troubles.
This technical report is applied to signal generators, cameras, monitors, standard converters, etc. of high definition television apparatuses used in program production.
|colorimetric parameter (colorimetry)||Specifications of color reproduction which consist of reference primary colors (3 primary colors and reference white) and signal processing (gamma characteristics, luminance equation, etc.)|
transmission method and the other is luminance (Y) and two color difference (PB, PR) signal transmission method. The R, G, B signal transmission method is used for signals of camera outputs. The Y, PB, PR signals are derived from R, G, B signals , which are calculated from R, G, B signals by matrix conversion as bellows, This matrix is called a transmission matrix.
For the “709” system,
|liner matrix||Camera imaging characteristics are derived from a tri-stimulus value function used for color matching of an equal energy spectrum color with specified 3 primary colors. As the 3 primary colors are inside a spectral color locus (horseshoe-shaped color gamut), negative optical values are needed mathematically for camera output. However actual camera outputs do not correspond to negative optical values. Therefore, an ideal imaging characteristics is approximately obtained using a matrix circuit in linear processing. This matrix is called a linear matrix.|
|monitor gamma||Optical outputs of CRT usually used in monitors (television receivers) are approximately in proportion to power of 2.2 of input voltage. This characteristic is called a monitor gamma.|
|CRT chromaticity||The 3 primary colors specified in “709”, “240M”, ITU 470-4B,G (“EBU” bellow), ITU 470-4M (“NTSC” bellow) are applied to displays in receivers. As CRT displays are mainly used for current television receivers, the 3 primary color chromaticity of CRT phosphors is called the CRT chromaticity. As a triangle formed by 3 primary colors on the chromaticity diagram in “NTSC” is wider, the phosphors for “NTSC” are difficult to be obtained. Therefore, the 3 primary color chromaticity for “709”, “240M”, “EBU” is defined, considering possibility of realizing.|
2. Amendment History
|Ver.||Amendment or Enactment Date||Amendment summary|