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Multimedia systems colorimetric characteristics

Opto-electronic and electro-optic conversions and so multimedia systems colorimetric characteristics specified in IEC 61966-2-1 [3.11], IEC 61966-2-2 [3.12], 61966-2-4 [3.13], and IEC 61966-2-5 (CDV) [3.14], are shown in Table 3.8.

TABLE 3.8

Multimedia systems colorimetric characteristics

IEC 61966-2-1 [3.11] sRGB
Reference display image characteristics      
Display luminance level 80 cd/m2
Display model offset (R, G and B) 0.0
Display input/output characteristics (R, G and B) 2.2
Display primaries   x y
Red 0.640 0.330
Green 0.300 0.600
Blue 0.150 0.060
White D65 0.3127 0.3290
 
Reference viewing conditions      
Reference background Background relative luminance is equal to 20 % reference display luminance level (16 cd/m2) for background as a part of display monitor; chromaticity coordinates are about x = 0.3127, y = 0.3290 (D65).
Reference surround 20 % reference luminance level of reference surround (4.1 cd/m2); chromaticity coordinates are about x = 0.3457, y = 0.3585 (D50).
Reference proximal field 20 % reference luminance level of display monitor (16 cd/m2); chromaticity coordinates are about x = 0.3127, y = 0.3290 (D65).
Reference ambient illuminance level 64 lx
Reference ambient white point x = 0.3457, y = 0.3585 (D50).
Reference veiling glare 0.2 cd/m2
 
Transformation from RGB values to CIE 1931 XYZ values where For black digital count KDC = 0 and a white digital count WDC = 255 for 8-bit/channel encoding: If then:

 

TABLE 3.8
(Continued)

  If then:
Transformation from CIE 1931 XYZ values to RGB values Note: In the RGB encoding process, negative sRGB tristimulus values and sRGB tristimulus values greater than 1.00 are not retained. The luminance dynamic range and color gamut of RGB is limited to the tristimulus values between 0.0 and 1.0 by simple clipping. If then: or if then: For KDC = 0 and WDC = 255 for 8-bit/channel encoding:
Transformation from sYCC to ѲŠ1931 XYZ values For 8-bit/channel encoding : 8-bit/channel encoding shall be the default sYCC encoding bit depth. Other bit depths may be unsupported for general use. For N-bit/channel encoding (N > 8): For 8-bit/channel encoding:

TABLE 3.8
(Continued)

  For N-bit/channel encoding (N > 8): If then If then If then For 8-bit/channel encoding:
Transformation from CIE 1931 XYZ values to sYCC values For N-bit/channel encoding (N > 8) greater accuracy is required, i.e. for 16 bit/channel: In the sYCC encoding process, negative sRGB tristimulus values and sRGB values greater than 1.0 are retained. If then If then If then

TABLE 3.8
(Continued)



  For 8-bit/channel encoding (the resulting values shall be limited from 0 to 255): For N-bit/channel encoding (the resulting values shall be limited from 0 to ):
Transformation from 8 bit sYCC values to 8 bit sRGB values Note: Since the 8 bit sYCC values are not limited by the gamut of 8 bit sRGB values, some kind of mapping is needed for the colors that contain over-ranged nonlinear floating point values (under 0.0 or over 1.0) when converting 8 bit YCC to 8 bit sRGB
Transformation from 8 bit sRGB values to 8 bit sYCC values
Extended gamut encoding for sRGB: bg-sRGB and its YCC transformation: bg-sYCC
Transformation from bg-sRGB values to CIE 1931 XYZ values For 10 bit/channel encoding (WDC = 894, KDC = 384): For N-bit/channel encoding (N > 10):

+

TABLE 3.8
(Continued)

  If then If then If then For 8 bit/channel encoding:
Transformation from CIE 1931 XYZ values to bg-sRGB+ values For N bit/channel encoding (N > 10) greater accuracy is required, i.e. for 16 bit/channel encoding: In the bg-sRGB encoding process, negative sRGB tristimulus values and sRGB, tristimulus values greater than 1.0 are retained. If , If then If then For N bit/channel encoding: For 10 bit/channel encoding (WDC = 894 and KDC = 384): For 10 bit/channel encoding the resulting bg-sRGB values shall be limited to a range from 0 to 1023. For other N bit/channel encoding (N > 10): For N bit/channel encoding (N > 10) the resulting bg-sRGB(N) values shall be limited to range from 0 to . 10 bit/channel encoding shall be the default bg-sRGB encoding bit depth. Other bit depths may be unsupported for general use.

 

TABLE 3.8
(Continued)

Transformation between sRGB 8 bit values ( ) and bg-sRGB 10 bit values ( ) The resulting sRGB(8) shall be limited to range from 0 to 255. For N bit/channel encoding: The resulting sRGB(8) shall be limited to range from 0 to
Transformation from bg-sYCC values to CIE 1931 XYZ values 10 bit/channel encoding shall be the default bg-sYCC encoding bit depth. Other bit depths may be unsupported for general use. For 10 bit/channel encoding: For N bit/channel encoding greater accuracy is required, i.e. for 16 bit/channel: The nonlinear values are than transformed into CIE 1931 XYZ values
Transformation from CIE 1931 XYZ values to bg-sYCC values ( ) The relationship between non-linear and is defined as follows: For 10 bit/channel encoding (WDC = 1023, KDC = 0, range = 1023/2, offset = 512): The resulting values shall be limited to range from 0 to 1023 10 bit/channel encoding shall be the default bg-sYCC encoding bit depth. Other bit depths may be unsupported for general use. For N bit/channel encoding (N > 10)

TABLE 3.8
(Continued)

  The resulting values shall be limited to a range from 0 to The maximum luminance of the achromatic axis of is equal to 1. The minimum luminance of the achromatic axis of is equal to 0.
IEC 61966-2-2 [3.12] scRGB
Transformation from CIE 1931 XYZ values to 16 bit scRGB values
Transformation from 16 bit scRGB values to CIE 1931 XYZ values
Transformation from 16 bit scRGB values to 8 bit sRGB values If else if else if else
Transformation from 8 bit sRGB values to 16 bit scRGB values If

 


TABLE 3.8
(Continued)

  else
Nonlinear encoding in 12 bit for scRGB: scRGB-nl and its YCC transformation: scYCC-nl if then if then if then 12 bit non-linear version of scRGB-nl: Quantization for 12 bit non-linear of scYCC-nl: Note that this quantization leads to the following relationships, where a value of 65535 in scRGB(16) is equivalent to 7.4999 in scRGB and 4080 in scRGB-nl. This is to ease computational implementations. Quantization relationships using scRGB
   
N/A -0.6038 -0.8000
-0.5 -0.7354
-0.25 -0.5371
0.0000
1.0000
1.3533
1.6125
1.8248
2.0080
2.1708
2.3184
7.4999 2.3876
N/A 7.5 2.3877
N/A 7.5913 2.4000
 

 

 

TABLE 3.8
(Continued)

IEC 61966-2-4 [3.13] xvYCC  
CIE chromaticities for reference primary colors and reference white        
  x y  
Red 0.640 0.330  
Green 0.300 0.600  
Blue 0.150 0.060  
White D65 0.3127 0.3290  
   
Opto-electronic transfer characteristics If , then: ) Else if , then: 4 Else if , then:
YCC encoding methods xvYCC601 for applications SDTV (ITU-R BT.601-5): xvYCC709 for applications HDTV (ITU-R BT.709-5):
Digital quantization methods For 8-bit representation: For n-bit (n>8) representation: Note: Bit levels “from 0 to ” and from “ to ” (0 and 255 in the case of 8-bit encoding) are used exclusively for synchronization and are not allowed for storing color values. Levels from to (from 1 to 254, in the case of 8 bit encoding) are available.

 

TABLE 3.8
(Continued)

Transformation from xvYCC values to CIE 1931 values For 8 bit/channel encoding: For N bit/channel encoding (N > 8): For encoding: For encoding: For For For
Transformation from CIE 1931 XYZ values to xvYCC values  

 

TABLE 3.8
(Continued)

  If : Else if : Else if : For 8 bit/channel representation (the resulting values shall be limited to a range from 1 to 255): For N-bit (N > 8) representation (the resulting values shall be limited to a range from to ):
IEC 61966-2-5 [3] opRGB
Reference image display system characteristics      
Display luminance level 160 cd/m2
Display model offset (R, G and B) 0.0
Display input/output characteristics (R, G and B) 2.2
Display primaries   x y
Red 0.640 0.330
Green 0.210 0.710
Blue 0.150 0.060
       
Display white point ( )
152.07 160.00 174.25
     
 
0.3127 0.3290  
Display black level 0.4 cd/m2
 
               

TABLE 3.8
(Continued)

Reference viewing conditions      
Reference background For the background as part of display screen, the background is 20 % of the reference display luminance level (32 cd/m2), the chromaticity should average to x = 0.3127, y = 0.3290 (D65).
Reference surround 20 % diffuse reflectance of the maximum reference ambient illuminance level (4.07 cd/m2); the chromaticity should average to x = 0.3457, y = 0.3585 (D50).
Reference proximal field 20 % reference luminance level of display monitor (16 cd/m2); chromaticity coordinates are about x = 0.3127, y = 0.3290 (D65).
Reference proximal field 20 % of the reference display luminance level (32 cd/m2); the chromaticity should average to x = 0.3127, y = 0.3290 (D65).
Reference ambient illuminance level 64 lx
Reference ambient white point x = 0.3457, y = 0.3585 (D50).
 
Transformation from opRGB values to CIE 1931 XYZ values  
Transformation from CIE 1931 XYZ values to opRGB values For 8 bit/channel encoding: For other N bit/channel (N > 8) encoding:  
Transformation from opRGB values to YCC values for image compression For N bit/channel encoding ( and ):  
           

 

TABLE 3.8
(End)

 
Transformation from YCC for image compression values to opRGB values For 8 bit/channel encoding : For other N-bit/channel encoding (N > 8): In op RGB encoding process, negative opRGB tristimulus values and opRGB greater than 1.00 are not retained by simple clipping. For 8 bit/channel encoding (the resulting values shall be limited to a range from 0 to 255): For other N bit/channel (N > 8) encoding (the resulting values shall be limited to a range from 0 to ):

Date: 2014-12-22; view: 1866


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