7.38. Umbral alfa

7.38. Umbral alfa
	7. El menú “Capa”

The Threshold Alpha command converts semi-transparent areas of the active layer into completely transparent or completely opaque areas, based on a threshold you set. It only works on layers which have an alpha channel. If the Lock alpha channel option is checked in the Layers dialog, the filter will have no effect.

7.38.1. Activar el comando

You can access this command from the menubar through Layer → Transparency → Threshold Alpha....

7.38.2. Descripción de la ventana del diálogo

Figura 16.121. The “Threshold Alpha” filter options dialog

Presets, Input Type, Blending Options, Preview, Split view

	Nota
	Estas opciones se describen en la Sección 2, “Características comunes”.

Value

The threshold alpha value determines which values will become transparent or opaque. You can set the transparency value to be used by using the slider or by entering a value between 0 and 1 in the input box. All transparency values above this threshold will become opaque and all transparency values below or equal to this threshold will become completely transparent.

	Nota
	Este comando nunca hará completamente transparente los píxeles opacos (valor alfa = 0).

Figura 16.122. Ejemplo de umbral alfa

Un degradado de transparencia 0-255.

Umbral ajustado a 50, 127, 210.