1、2 CCIR VOLUME*XI-1 90 4855232 0504394 b Rec. 471-1 RECOMMENDATION 471-1 NOMENCLATURE AND DESCRIPTION OF COLOUR BAR SIGNALS (Question 1/11) (1970-1986) The CCIR, CONSIDERING (a) that a number of different colour bar signals used for measurement and adjustment purposes are recorded on magnetic tape, t
2、ransmitted on national and international circuits or radiated from television transmitters; (b) that the particular signal in use cannot be readily recognized from the video picture-signal waveform: (c) that coloured patterns comprising several vertical bars of colour, involving only the primary hue
3、s and their complements at particular values of saturation and in descending order of luminance, are frequently used to confirm the correct operation of colour coding, decoding and processihg equipment, .I UNANIMOUSLY RECOMMENDS 1. that the following nomenclature is used to identify and distinguish
4、between colour bar signals; 1.1 a colour bar generator is assumed to have three outputs corresponding respectively to the red, green and blue primary colour signals, (EL, Ei; and E) which are then used as input signals to a colour coder. The signal amplitudes enumerated below refer to these coder in
5、put signals expressed as a percentage of the white level (see, for example, Recommendation 567, Part B, 0 B.l and Report 624, Fig. I), taking this as 100% with the blanking level as zero. During the transmission of colour bars the signal levels should be enumerated in the following order, with an ob
6、lique stroke between the numbers: - the primary colour signal level during the transmission of the “white” colour bar, i.e. maximum value of EL, Ei; and E; the primary colour signal level during the transmission of the “black” colour bar, i.e. minimum value of EL, E(; and Eh; the maximum level of th
7、e primary colour signal during transmission of “coloured” colour bars, ire. maximum value of EL or E(; or EL; the minimum level of the primary colour signal during transmission of “coloured” colour bars, i.e. minimum value of ER or EL or EL. Example: Four versions of colour bars are in general use a
8、rid are illustrated in Fig. 1, which shows the individual components of the red, green and blue primary colour signals as they are generated for four different types of colour bar signal. This data would be expressed as follows: - - - Colour bars (u) 100 / O / 100 / O Colour bars (b) 100 / O / 75 /
9、O Colour bars (c) 100 / O / 100 / 25 Colour bars (d) 75 / 7.5 / 75 / 7.5 2. operational environments; that the waveforms shown in Fig. 1 be used to ensure conformity between measurements made in different 3. Report 624. that all definitions and calculations relating to descriptions of colour bars sh
10、all be consistent with - - I I -. CCIR VOLUME*XI-1 90 4855212 0504395 8 Rec. 471-1 3 Red signai Green signal Blue signai 100 - 0- 100 - 75 - O (a) lOO/O/loO/O colour bars li WY II MR BBK - CG (b) iOO/O/15/0 colour bars R 1 B BK H YCGMRBBK YCGMRBBK (c) loO/O/lOO/25 colour bars . k R BBK Ih NYCGM L G M R BBK II NYC N Y C G M R B BK (d) 15/1.5/15/1.5. colour bars FIGURE 1 - Relative amplitudes of colour bars for dflerent types of generator W: white Y: yellow C: cyan (turquoise) G: green M: magenta (purple) R red II: blue BK: black - -. -_ _- -7
