8.25. Mesclador mono

8.25. Mesclador mono
	8. El menú «Colors»

8.25.1. Resum

Figura 16.197. Aplicació del mesclador mono

Imatge original

Aplicació de l'ordre «Mesclador mono» amb les opcions per defecte.

	Nota
	This command does not work on Grayscale images. If the image is Grayscale, the menu entry is disabled.

8.25.2. Activa l'ordre

Podeu trobar aquesta ordre a Colors → Components → Mesclador mono….

8.25.3. Opcions

Figura 16.198. Opcions de l'ordre «Mesclador mono»

Presets: «Presets» are a common feature for several Colors commands. You can find its description in Secció 8.1.1, «Característiques comunes dels colors».
Preserva la lluminositat: The mixing can result in an image where some of the colors are too light. This option lessens the luminosity of the color channels while keeping a good visual ratio between them. So, you can change the relative weight of the colors without changing the overall luminosity.
Multicopista del canal vermell, Multicopista del canal verd, Multicopista del canal blau: Coeficient aplicat a cada canal. L'interval de valors està entre -5.000 i 5.000. Com que els valors predeterminats són iguals en els tres canals, la imatge està en gris.
Blending Options, Preview and Split view: These are common features described in Secció 8.1.1, «Característiques comunes dels colors».

8.25.4. Using Mono Mixer

When this filter is opened, the image preview turns to grayscale, but the image is still a RGB image with three channels, until the OK button is pressed.

Figura 16.199. Red: 100% Green: 50% Blue: 0%. Preserve Luminosity unchecked.

A cada quadrat, els píxels s'han convertit en un nivell de gris igual al valor del canal vermell de la imatge original (el fons s'ha pintat amb color rosa un cop fet visibles tots els quadrats).

Here is how the Preserve Luminosity works in the monochrome mode: «For example, suppose the sliders were Red:75%, Green:75%, Blue:0%. With Preserve Luminosity disabled, the resulting picture would be at 75%+75%+0% =150%, very bright indeed. A pixel with a value of, say, R,G,B=127,100,80 would map to 127*0.75+100*0.75+80*0=170 for each channel. With Preserve Luminosity enabled, the sliders will be scaled so they always add up to 100%. In this example, that scale value is 1/(75%+75%+0%) or 0.667. So the pixel values would be about 113. The Preserve Luminosity option just assures that the scale values from the sliders always adds up to 100%. Of course, strange things happen when any of the sliders have large negative values.» (from the plug-in author himself).

	Nota
	Which channel should you modify? This depends on what you want to do. In principle, the Red channel suits contrast modifications well. The Green channel is well adapted to details changes and the Blue channel to noise, grain changes. You can use the Decompose command.