Pixlr Editor/A few concepts

Introduction
This section is for the beginner in graphics software usage mostly. It is intended to briefly present objects and attributes often used when working with computer graphics.

Layer
Unit of content permitting the separation of various part of a whole image, set up one on top of the other. Each layer represent a part of the image that can worked independently from the others. Generally, the image with be the result of the merge of all the layers.

Mask
A mask is a surface put on a layer to mask, read to hide certain parts of the layer in norder to modify the ones that are not masked. The mask has to be applied to alter the layer qui eliminating all that is masked.

Anti-aliasing
A mitigation of the outline of a form by filling certain gaps on the border of the form with milder tone of the main color.

Feathering


In Pixlr Editor, feathering is a property of the selection and lasso tools, comparatively to other software, notably Photoshop, where feathering is a tool in itself or a directly applicable function.

Feathering represents the level of hardness of the border of a selection. If the level of feathering is at 0, the selection border is clear cut: there is an inside and an outside of the selected area in a discontinuous manner. If the feathering level rises, the pixels on either side of the border line of the selection blend their colors progressively in respect to their distance to this line.

The level of feathering must be chosen prior to making a selection.

Tolerance
The threshold of tolerance represents the proximity of color for which a color change will be applied: less tolerance means only the colors very close to the target color will be changed, more tolerance means a wider range of colors will be affected. This options applies to the following tools:
 * Paint bucket tool
 * Color replace tool
 * Red eye reduction tool

Opacity
Opacity concerns the level of transparency affecting a layer or a drawing tool. When the opacity is at 100, the color will completely block out any underlying colors. At the other end, when opacity is at 0, any addition will be completely transparent.

Opacity can be applied at any time to the layer, but must be selected for drawing tools before they are used.

HSL (Hue, Saturation and Lightness), RGB (Red, Green and Blue), WEB, and IMG Color Models
Each of these color coding system are available in the Color Selector.