7.6. Ruido RGB

7.6. Ruido RGB
	7. Filtros de ruido

7.6.1. Generalidades

Figura 17.154. Ejemplo de aplicación del filtro “Ruido RGB”

Imagen original

Filtro “Ruido RGB” aplicado

The RGB Noise filter adds a normally distributed noise to a layer or a selection. It uses the RGB color model to produce the noise (noise is added to red, green and blue values of each pixel). A normal distribution means, that only slight noise is added to the most pixels in the affected area, while less pixels are affected by more extreme values. (If you apply this filter to an image filled with a solid gray color and then look at its histogram, you will see a classic bell-shaped Gaussian curve.)

El resultado es un ruido muy natural.

7.6.2. Activating the Filter

This filter is found in the main menu under Filters → Noise → RGB Noise….

7.6.3. Opciones

Figura 17.155. Opciones del filtro “Ruido RGB”

Presets, “Input Type”, Recortar, Blending Options, Vista previa, Merge filter, Split view

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

Ruido correlativo

Noise may be additive (uncorrelated) or multiplicative (correlated - also known as speckle noise). When checked, every channel value is multiplied by a normal distributed value. So the noise depends on the channel values: a greater channel value leads to more noise, while dark colors (small values) tend to remain dark.

RGB independiente

When this radio button is checked, you can move each RGB slider separately. Otherwise, the sliders R, G and B will be replaced by a single slider Value. The same relative noise will then be added to all channels in each pixel, so the hue of pixels does not change much.

RGB lineal

Funciona con datos de color RGB linealizados.

Distribución Gaussiana

Utiliza una distribución de ruido gaussiana. Cuando no está marcado, se utiliza en su lugar una distribución de ruido lineal.

Rojo, Verde, Azul, Alfa

These slidebars and adjacent input boxes allow to set noise level (0.00 - 1.00) in each channel.

El valor de estos deslizadores determina la desviación estándar de la distribución normal del ruido aplicado. La desviación estándar usada es la mitad del valor elegido (donde 1 es la distancia entre el menor y mayor valor posible en el canal).

Semilla aleatoria, New Seed

This option controls the randomness of the filter. The Random seed box lets you manually enter a seed for the randomization algorithm used. You can also generate a random seed by pressing the New Seed button. If the same random seed is used in the same situation, the filter produces exactly the same results. A different random seed produces different results.