LAB_PARAMS

typedef struct 
{ 
   L_UINT uStructSize; 
   L_INT nMask; 
   L_INT L_offset; 
   L_INT L_range; 
   L_INT a_offset; 
   L_INT a_range; 
   L_INT b_offset; 
   L_INT b_range; 
} LAB_PARAMS, *LPLAB_PARAMS; 

The LAB_PARAMS structure provides information about CIELab conversion properties.

Parameter Description
uStructSize Size of this structure.
nMask Masking value:
  Value Meaning
  LAB_L_OFFSET Change L_offset value
  LAB_L_RANGE Change L_range value
  LAB_a_OFFSET Change a_offset value
  LAB_a_RANGE Change a_range value
  LAB_b_OFFSET Change b_offset value
  LAB_b_RANGE Change b_range value
L_offset L component offset
L_range L componnt range
a_offset a component offset
a_range a Component range
b_offset b Component offset
b_range b Component range

Comments

The gamut capacity is expressed as an offset and range, with the exception of the minimum and maximum values. For example, in the T.42 CIELab, the communication conversion can be expressed as:

L_offset = 0;
L_range = 100
a_offset = 128
a_range = 170
b_offset = 96
b_range = 200

For more information on the CIELab color conversion, refer to http://www.itu.int/en/pages/default.aspx.

LAB_PARAMS is used with the CONVERSION_PARAM structure.

The mask value will be used only when updating the CMYK conversion using L_ClrSetConversionParams function.

Help Version 19.0.2017.10.27
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