Map and Table Calculation

CLRGREY( ) function

Returns the Grey component of an (R,G,B) color.

Syntax

CLRGREY(Color)

Input

Color	is a map or a column with the Color domain or a picture domain, or an expression which results in a color
Domain type:	system domain Color or a Picture domain

Output

CLRGREY returns:	a value
Domain:	system domain Image

Notes:

The CLRGREY(Color) function is equivalent to MAPCOLORSEP(InMap, Grey) operation.
Grey = 0.3 * Red + 0.59 * Green + 0.11 * Blue.

Tips:

The function can also be used to calculate with colors in a representation class that is opened as a table.
For more information on colors, see also Color separation : functionality or Color separation : algorithm.
When the definition symbol = is used, a dependent output map or dependent output column is created; when the assignment symbol := is used, the dependency link is immediately broken after the output map/column has been calculated.

Usable in

Examples

Pocket line calculator example:

? CLRGREY(RPRCOLOR(Landuse,"Airport")

returns the grey component of class "Airport" from representation Landuse, e.g. 77

TabCalc example:

Grey = CLRGREY(Color)

MapCalc example:

LandColor = MAPCOLOR(Landuse)

Grey = CLRGREY(LandColor)

Landuse

LandColor

Grey