LAB_PARAMS

typedef struct _LAB_PARAMS 
{ 
   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.

Parameters

uStructSize

Size of this structure.

nMask

Masking 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 https://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.