2.2. Herramienta de selección rectangular
| 2. Herramientas de selección |

### 2.2. Herramienta de selección rectangular

Figura 13.4. El icono de la herramienta de selección rectangular en la caja.

The Rectangle Selection tool is designed to select rectangular regions of the active layer: it is the most basic of the selection tools, but very commonly used. For information on selections and how they are used in GIMP see Selections; for information on features common to all selection tools see Selection Tools.

Esta herramienta puede ser utilizada para pintar un rectángulo en la imagen. Para hacer un rectángulo relleno cree una selección rectangular, y luego rellénela empleando la cubeta. Para hacer sólo el contorno del rectángulo, la manera más simple y flexible es crear una selección rectangular y luego trazarla.

#### 2.2.1. Activating the tool

Puede acceder a esta herramienta de selección de varias maneras:

- from the image menu bar Tools → Selection Tools → Rectangle Select,

- by clicking on the tool icon in the ToolBox,

- by using the keyboard shortcut R.

#### 2.2.2. Key modifiers

| Nota
En la sección Herramientas de selección se encuentran las teclas modificadoras que afectan a todas estas herramientas de la misma forma. Sólo los efectos específicos a la herramienta de selección rectangular son explicados aquí.

Ctrl

  Pressing the Ctrl key after starting your selection, and holding it down until you are finished, causes your starting point to be used as the center of the selected rectangle, instead of a corner. Note that if you press the Ctrl key before starting to make the selection, the resulting selection will be subtracted from the existing selection. The cursor becomes

Shift

  If you press the Shift key before starting the selection, the resulting selection will be added to the existing one. The cursor becomes

  Pressing the Shift key after starting your selection, toggles the Fixed option, and holding it down until you are finished, will constrain the selection to a square, if it is your first selection. Later, with the default Aspect Ratio , your selection will respect the aspect ratio of the previous selection.

Ctrl+Shift

  Pressing both keys after starting your selection combines the two effects, giving you a square selection centered on your starting point. Note that pressing these keys before starting your selection intersects the resulting selection with the existing one and the pointer change shape accordingly :

#### 2.2.3. Tool manipulation

Figura 13.5. Example of Rectangle Selection.

When this tool is selected the mouse pointer is displayed like this: as soon as it is over the image. A drag and drop allows to get a rectangular (or square) shape. When the mouse button is relaxed, a dotted line (“marching ants”) outlines the selection. It's not necessary to adjust the selection with care; you can resize it easily later.

When the pointer is moving on the canvas, the pointer and selection aspects change:

- outside the selection it looks like previously; this allows to design a new selection but will erase the existing one if this isn't combined with an action on the relevant key to add or subtract another selection as described in the previous paragraph.

- within selection peripheral parts, the mouse pointer changes into various shapes when overflying rectangular sensitive and clearly marked areas. These handles allow you to resize the selection. In selection corners the pointer changes into a shape according to the context; for instance in the low right corner it becomes: . So, by click-and-dragging these areas, you can magnify or shrink the selection size. Over median selection parts, lateral, low or up, pointer is changed into appropriate shapes according to the context. For instance, when the mouse pointer is over the median right side, the pointer looks like: . So you can click-and-drag to magnify or to shrink the selection size by moving the chosen boundary.

- inside selection central area the mouse pointer looks like usual for object manipulation, i.e.: . So you can move the whole selection by a click-and-drag.

Moreover, if you have not unchecked the Highlight option, your work will be easier because what is out the selection will be darkest than what is in the selection, and then the selection seems highlighted.

| Sugerencia
If you use moving keys you can move the selection or modify its size by one pixel step. If you use it in combination with Shift you can move it by a 25 pixel step.

Figura 13.6. Sensitive selection areas

Display of all possible pointers in function of their localization with respect to the selection area.

After creating and modifying the selection, you will have to exit this editing mode (and commit any changes). You can do this with a single click inside the selection or by pressing the Enter key. Or you can just use a non-selection tool and, for example, fill or paint the selection.

#### 2.2.4. Tool Options

Figura 13.7. Las opciones de la herramienta de selección rectangular.

Normally, tool options are displayed in a window attached under the Toolbox as soon as you activate a tool. If they are not, you can access them from the image menu bar through Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.

| Nota
Diríjase a la sección Herramientas de selección para conocer las opciones que son comunes a todas las herramientas de este grupo. Aquí sólo se explican las opciones específicas a la herramienta de selección rectangular.

Mode; Antialiasing; Feather edges

  Common select options.

Rounded corners

  If you enable this option, a slider appears. You can use this to adjust the radius that is used to round the corners of the selection.

Expand from center

  If you enable this option, the point the selection is started by pressing the mouse button is used as center of the selected area.

Fixed

  Este menú le permite restringir la forma del rectángulo de tres maneras diferentes.

  Selección libre

    Esta opción le permite redimensionar la selección mientras se mantiene fija su proporción, según los dos números ingresados en los controles de anchura y altura.

  Tamaño fijo

    Esta opción le permite especificar manualmente un tamaño para la selección, empleando los controles de anchura, altura y unidad.

  Height

    With this choice you can fix the height of the selection.

  Tamaño

    With this choice you can fix the width and height of the selection.

X; Y; Width; Height

  These four text fields contain the current place and size of the selection. You can use these fields to adjust size and place of the selection by numbers.

Highlight

  If you enable this option, the selected area is emphasized by a surrounding mask to make visual selection much easier.

Guides

  With this menu you can select the type of guides that is shown within the selection to make the creation of a selection easier, respecting Photo composition rules.

  No Guides

    No guides are shown at all.

  Center lines

    Only center lines are shown as guides within the selected area.

  Rule of thirds

    Guides are shown along the rule of thirds while creating the selection.

  Golden sections

    With this option, guides show up to mark the golden sections.

Encoger selección automáticamente

  La casilla Encoger selección automáticamente hace que la selección se ajuste automáticamente, encogiéndose para contener tan solo la forma de la capa de la imagen que se encuentra adentro. El algoritmo que halla el mejor rectangulo que se ajuste es “inteligente”, lo que en este caso significa que algunas veces realiza cosas sorprendentemente sofisticadas, y otras veces realiza cosas sorprendentemente extrañas. En cualquier caso, si la región que desea seleccionar tiene un contorno suficientemente sólido, esta herramienta se comportará correctamente. Note que la selección resultante no necesariamente tendrá la misma forma que el rectángulo que Ud. trace.

Shrink merged

  Si además se encuentra activa la opción Muestra combinada, al encogerse la selección automáticamente se tendrá en cuenta la información de los píxeles visibles de toda la imagen, en lugar de considerarse sólo la información de la capa activa. Para mayor información sobre la muestra combinada, diríjase a la entrada del glosario Muestra combinada.

2. Herramientas de selección |  | 2.3. Herramienta de selección elíptica