7.6. RGB-støy

7.6.1. Oversyn

Figur 17.152. Eksempel på bruk av filteret «RGB-støy»

Eksempel på bruk av filteret «RGB-støy»

Originalbiletet

Eksempel på bruk av filteret «RGB-støy»

Eksempel på bruk av filteret «RGB-støy»


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.)

Resultatet ser svært naturleg ut.

7.6.2. Activating the Filter

This filter is found in the main menu under FiltersNoiseRGB Noise….

7.6.3. Innstillingar

Figur 17.153. Innstillingane for filteret «RGB-støy»

Innstillingane for filteret «RGB-støy»

Presets, «Input Type», Clipping, Blending Options, Preview, Split view
[Notat] Notat

These options are described in Del 2, «Common Features».

Korrelatert støy

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.

Uavhengig RGB

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.

Linear RGB

Operate on linearized RGB color data.

Gaussian distribution

Use a gaussian noise distribution. When unchecked, a linear noise distribution is used instead.

Raud, Grøn, Blå, Alfa

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

Verdiane sett med brytarane er eigentleg standardavvik i høve til normalfordelinga av tillagt støy. Det brukte standardavviket er halvparten av den viste verdien. 1 er avstanden mellom den lågaste og høgaste moglege verdien i ein kanal.

Tilfeldig frø

Controls randomness of noise. 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. Random seed can be entered manually or generated randomly by pressing the New Seed button.