3. Image-content Related Dialogs

3.1. FG/BG Color Dialog

Obrázek 15.26. The FG/BG Color dialog

The FG/BG Color dialog

Dialog Barvy umožňuje spravovat a vybírat nové barvy. Je rozdělen do několika samostatných částí: GIMP, Trojúhelník, Vodová barva a Stupnice. Poslední tlačítko v dialogu aktivuje kapátko, kterým můžete nasát barvu kdekoliv na obrazovce (i mimo Gimp).

The dialog called from the FG/BG area in the toolbox is a bit different compared to the one called from the image menu:

  • the sliders are permanently visible instead of selected from the scale menu,

  • twelve buttons show the last used colors. You may choose a color by clicking on one of these buttons or add the current FG or BG color to this history list.

This dialog works either on the foreground or the background color.

3.1.1. Aktivace dialogu

The Colors dialog is a dockable dialog; see the section 2.3 – „Dokování dialogů“ for help on manipulating it.

You can access it:

  • from an image menu: WindowsDockable DialogsColors;

  • from the Tab menu in any dockable dialog by clicking on and selecting Add TabColors,

  • z Panelu nástrojů: klikněte na barvu popředí či pozadí.

In the Windows menu, there is a list of detached windows which exists only if at least one dialog remains open. In this case, you can raise the Colors dialog from the image-menu: WindowsColors.

3.1.2. Using the FG/BG color dialog

Volič GIMP

Volič barev GIMP umožňuje výběr libovolné barvy kliknutím do jednorozměrného proužku vpravo a následným kliknutím do dvojrozměrné plochy vlevo. Jednorozměrný proužek umožňuje volit jeden z parametrů barvy (odstín, sytost, hodnota, červená, modrá, zelená), jak zvolíte kliknutím na některé z tlačítek v pravé části dialogu. Dvojrozměrná plocha pak umožňuje zvolit zbývající dva doplňkové parametry.


Obrázek 15.27. CMYK


Volič barev CMYK umožňuje vybírat barvy podle barevného modelu (FIXLINK) CMYK.


Obrázek 15.28. Trojúhelník


Volič Trojúhelník se skládá z barevného kruhu, který umožňuje kliknutím a tažením vybrat žádaný barevný odstín, a trojúhelníku, ve kterém lze podobným způsobem intuitivně vybrat sytost a hodnotu (jas) barvy.

Vodová barva

Obrázek 15.29. Vodová barva

Vodová barva

This color selector is symbolized by a brush. The function mode of this selector is a little different from that of models presented so far. The principle consists in changing the current foreground color by clicking in the rectangular palette. If the current foreground color is for example white, then it turns to reddish by clicking in the red color area. Repeated clicking strengthens the effect. With the slider, which is right apart from the color palette, you can set the color quantity per every mouse click. The higher the sliding control is, the more color is taken up per click.


Obrázek 15.30. Palette Color Selector

Palette Color Selector

This color selector brings up a list of the colors of the current palette in the Palettes dialog . You can set GIMP's foreground or background colors by clicking on colors in the colors display. You can also use the arrow keys to move within the list of colors.


Obrázek 15.31. Stupnice




The color picker has a completely different behavior, than the color picker tool. Instead of picking the colors from the active image, you're able to pick colors from the entire screen.

The downside is that you get colors after they got processed by the full system color stack, in particular color management. It means that the resulting color values may end up different from ones returned by the color picker tool when picking over the canvas. It is up to you to make an informed choice of which color picker to use.

HTML Notation

See HTML notation. You can also use the CSS keywords; enter the first letter of a color to get a list of colors with their keyword :

Obrázek 15.32. CSS keywords example

CSS keywords example

Right-clicking in the HTML Notation text box opens a context menu that allows you to edit your notation, particularly to paste a complex notation you have copied elsewhere. This menu leads to various Input Methods that allow you to use foreign characters, and to the possibility to Insert Unicode Control Characters. This is a vast field, beyond this help. Please see [UNICODE].

Obrázek 15.33. The HTML Notation context menu

The HTML Notation context menu

Right up you find a symbol, consisting of two arrows, with which you can exchange the foreground and background color. At the bottom left of the dialog, just below the foreground color block, you find a switching surface with two small, one black and the other white, partially overlapping squares. If you click on these, the front and background color are put back to black and white respectively.