4.8. Perspektiva

4.8. Perspektiva
	4. Transform Tools

The Perspective Tool is used to change the „perspective“ of the active layer content, of a selection content or of a path. When you click on the image, according to the Preview type you have selected, a rectangular frame or a grid pops up around the selection (or around the whole layer if there is no selection), with a handle on each of the four corners. By moving these handles by click-and-drag, you can modify the perspective. At the same time, a „Transformation information“ pops up, which lets you valid the transformation. At the center of the element, a circle lets you move the element by click-and-drag.

	Poznámka
	This tool is not actually a perspective tool, as it doesn't impose perspective rules. It is better described as a distort tool.

4.8.1. Activating the Tool

There are different possibilities to activate the tool:

From the main menu: Tools → Transform Tools → Perspective.
By clicking the tool icon in the Toolbox.
By pressing the Shift+P keyboard shortcut.

4.8.2. Options

Obrázek 14.108. „Perspective“ tool options

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 main menu through Windows → Dockable Windows → Tool Options which opens the option window of the selected tool.

Transformovat, Směr, Cubic (sometimes called „Bicubic“): The color of each pixel is computed as the average color of the eight closest pixels in the original image. This usually gives the best result, but it naturally takes more time., Clipping, Show image preview, Guides

	Poznámka
	These options are described in Transform tools common options.

Constrain handles (Shift)

Constrain handles to move along edges and diagonal.

Around center (Ctrl)

Transform around the center point.

4.8.3. The Perspective adjustment dialog

Obrázek 14.109. The Perspective adjustment dialog

When you click on the image window, the adjustment dialog appears.

Transform Matrix: The information window shows a mathematical representation of the perspective transformation. You can find more information about transformation matrices on Wikipedia.
Readjust button: With this button you can reset the transform handles back to the original square shape, while keeping the current transformation and zoom level. This enables you to create more complex transformations by making the transformation in several steps.