Digital video coding system colorimetric characteristics referred toMPEG-2,

MPEG-4, MPEG-4/AVC

Digital video coding system colorimetric characteristics specified in MPEG-2 – H.262 | 13818-2 [3.15, 3.16], MPEG-4 – 14496-2 [3.17, 3.18], H.264 | MPEG-4/AVC – 14496-10 [3.19] are shown in the Tables 3.9, 3.10, 3.11, which combine according data from Tables 6-7, 6-8, 6-9 from standard 13818-2, Tables 6-8, 6-9, 6-10 from standard 14496-2 and Tables E-2, E-3, E-4 from standard 14496-10.

Primaries chromaticity coordinates and reference white for given parameter values of
color_primaries are shown it Table 3.9.

Opto-electronic conversion characteristics – transfer primaries channels characteristics for given parameter values of transfer_characteristics are shown in Table 3.10. Table specifies:

– relative luminance levels – image components;

V– relative levels of gamma-corrected signals – image components ( );

– normalized luminance signal, ;

, – color-difference signals normalized to .

Luminance signals and color-difference signals matrixes coefficients for given parameter values of transfer_characteristics are shown in Table 3.11. For maintaining form of coefficient definitions, accepted in standards, matrixes coefficients of ITU-T H.262 | ISO/IEC 13818-2 and ISO/IEC 14496-2 standards are given in 3 column; matrixes coefficients of ITU-T H.264 | ISO/IEC 14496-10 standard are given in 4 column through K_R and K_B, used for matrix conversion description as following:

(3.154)

(3.155)

(3.156)

with exception of cases when transfer_characteristics values are equal to 0 and 8.

Value 8 in ITU-T H.262 | ISO/IEC 13818-2, ISO/IEC 14496-2 and ITU-T H.264 | ISO/IEC 14496-10 accords to signal coding , processed by algorithms specified in these standards, where signals are in terms of .

Value 0 in ITU-T H.264 | ISO/IEC 14496-10 accords to coding space signals coding processed by algorithms specified in Annex E.2 of standard ITU-T H.264 | ISO/IEC 14496-10.

TABLE 3.9
Digital video coding system colour primaries referred to MPEG-2, MPEG-4, MPEG-4/AVC

TABLE 3.9
(End)

TABLE 3.10
Digital video coding system transfer signal source characteristics referred to MPEG-2, MPEG-4, MPEG-4/AVC

transfer_characteristic	Systems and standards	Transfer characteristic
	Forbidden (ISO/IEC 13818-2 and ISO/IEC 14486-2)
Reserved (ISO/IEC 14486-10)	For future use ITU-T/ISO/IEC
	Recommendation ITU-R BT.709-5 [3.6] Recommendation ITU-R BT.1361 [3.9] conventional color gamut system (functionally the same as the value 6)
	Unspecified	Image characteristics are unknown or are determined by the application
	Reserved	For future use by ITU-T/ISO/IEC
	ITU-R Recommendation BT.470-6 system M (historically) Recommendation BT.1700 [3.3] 625 PAL or 625 SECAM (ISO/IEC 14486-2) US NTSC 1953 Recommendation for transmission standards for color television US FCC Title 47 Code of Federal Regulations (2004) 73.682 (a) (20)	Assumed displayed gamma 2.8 (this value conflicts with ITU-R Recommendation BT.1700 (2007 revision) and accordingly to this Recommendation has to be changed to 2.2)
	ITU-R Recommendation BT.1700 [3.3] 625 PAL or 625 SECAM (ISO/IEC 13818-2, 14496-10) ITU-R Recommendation BT.470-6 systems B, G (historically)	Assumed displayed gamma 2.8 (this value conflicts with ITU-R Recommendation BT.1700 (2007 revision) and accordingly to this Recommendation has to be changed to 2.2)

TABLE 3.10
(End)

	ITU-R Recommendation BT.1700 [3.3] NTSC ITU-R Recommendation BT.1358 [3.6] 525 or 625 SMPTE 170M [3.2] (functionally the same as the value 1) ITU-R Recommendation BT.601-6 [3.4] 625 (ISO/IEC 13818-2 and 14486-2)	See Eq. 3.141
	SMPTE 240M (1987) [3.21]	Opto-electronic conversion:
	Linear transfer characteristic
(ISO/IEC 13818-2, ISO/IEC 14486-2)
(ISO/IEC 14486-10)
	Logarithm transfer characteristic (100:1 range)
	Logarithm transfer characteristic (316.22777:1 range )	(in ISO/IEC 14486-2: )
	IEC 61966-2-4 [3.13]
	Recommendation ITU-R BT.1361 [39], extended color gamut system	(3.164)
9-255		Reserved for future use ITU-T/ISO/IEC

Table 3.11
Matrix coefficients defined for video coding system referred to MPEG-2, MPEG-4, MPEG-4/AVC

matrix_coefficients	Systems and standards	Matrix
ISO/IEC 13818-2 ISO/IEC 14486-2	ISO/IEC 14486-10
		Forbidden	RGB
	Recommendation ITU-R BT.709-5 [3.6] Recommendation ITU-R BT.1361 [3.9], conventional color gamut system and extended color gamut system IEC 61966-2-4 xvYCC709 [3.13] SMPTE RP 177 Annex B [3.1]
		Unspecified. Image characteristics are unknown or determined by the application
		Reserved. For future use ITU-T/ISO/IEC
	US NTSC 1953 Recommendation for transmission standards for color television US FCC Title 47 Code of Federal Regulations (2004) 73.682 (a) (20)
	ITU-R Recommendation BT.1700 [3.3] (2007 revision) 625 PAL and 625 SECAM ITU-R Recommendation BT.1358 [3.5] 625 IEC 61966-2-4 xvYCC709 [3.13] ITU-R Recommendation BT.470-6 systems B, G (historical) (Functionally the same as the value 6) ITU-R Recommendation BT.601-6 [3.4] 625 (Functionally the same as the value 6) (ISO/IEC 13818-2, ISO/IEC 14486-2)

TABLE 3.11
(Continued)

	ITU-R Recommendation BT.1700 [3.3] (2007 revision) NTSC ITU-R Recommendation BT.1358 [3.5] 525 SMPTE 170M [3.2] IEC 61966-2-4 xvYCC601 [3.13] (Functionally the same as the value 5) ITU-R Recommendation BT.470-6 systems B, G (historical) (Functionally the same as the value 6) ITU-R Recommendation BT.601-6 [3.4] 525 (Functionally the same as the value 5) (ISO/IEC 13818-2, 14496-2)
	SMPTE 240M (1987) [3.21]
		YCgCo
9-255		Reserved. For future use ITU-T/ISO/IEC

TABLE 3.11
Continued)

is analog with the value 0 associated with nominal black and the value 1 associated with nominal white; and are analog with the value 0 associated with both nominal black and nominal white; When transfer_characteristics is not equal to 11 or 12, has values between 0 and 1; When transfer_characteristics is not equal to 11 or 12, and have values between -0.5 and 0.5; When transfer_characteristics is not equal to 11 (IEC 61966-2-4) or 12 (ITU-R Recommendation BT.1361 extended color gamut system), are analog with a larger range not specified in this International Standard; are related to by the following formulae:
	If video_range is equal to 0:
If video_range is equal to 1: for n bit video.
– If matrix_coefficients is equal to 8 , the following applies:
	If video_range is equal to 0:

TABLE 3.11
(End)

Note 1 – For purposes of the nomenclature used in Table, and d in the above equations may be referred to as and , respectively. The inverse conversion for the above three equations should be computed as: Note 2 – The decoding process given in the Recommendation | International standard limits output sample values for Y, Cr and Cb to the range [0:255]. Thus, sample values :outside the range implied by the above equations may occasionally occur at the output of the decoding process/ In particular the sample values 0 and 255 may occur In the case that sequence_display_extension() is not present in the bitstream or color_description is zero the matrix coefficients are assumed to be implicitly defined by the application. Note 3 – In applications which may have signals with more than one set of color primaries, transfer characteristics, and/or matrix coefficients, it is recommended to transmit a sequence display extension with color_description set to one, and to specify the appropriate values for the colorimetry parameters.

If video_range is equal to 0: for n bit video. are related to R, G and B by the following formulae: Note – For purposes of the nomenclature used in Table, and in the above equations may be referred to as and , respectively. The inverse conversion for the above three equations should be computed as: In the case that video_signal_type() is not present in the bitstream or color_description is zero the matrix coefficients are assumed to be those corresponding to matrix_coefficients having the value 1. In the case that video_signal_type() is not present in the bitstream, video_range is assumed to have the value 0 (a range of Y from 16 to 235 for 8-bit video).

Date: 2014-12-22; view: 1321