10.15. rgba#

class itom.rgba(r, g, b, alpha=255)#

Color value object (RGB + optional alpha channel).

Creates a new color value from red, green, blue and optional alpha. If any value > 255 is passed as argument, its modulo with 256 is taken instead.

The rgba object implements many methods of the number protocol, such that it becomes possible to add, subtract, multiply… two colors. In most cases these operations are executed for each color component independently.

Parameters:

rint: red component [0,255].
gint: green component [0,255].
bint: blue component [0,255].
alphaint, optional: alpha component [0,255], default: 255 (opaque).

Notes

For a gray value set all colors to the same value.

name() → str#: Returns the name of this object (rgba).

toGray() → float#

returns the gray value from the color (alpha is not considered)

Returns:

float: The returned gray value is a float value and calculated by 0.299 * r + 0.587 * g + 0.114 * b

alpha#: int : alpha (transparency) component of this color [0, 255].

b#: int : blue component of this color [0, 255].

g#: int : red component of this color [0, 255].

r#: int : red component of this color [0, 255].