Layer technique

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Different levels in a graphics program, not overlapping. To the right of this is the dialog for managing the levels

With the layer technique in image processing , elements of the image are distributed on different layers . These can be edited individually and combined with one another in various ways. The technology is standard in image processing.

Working with layers

Layers are like see-through (transparent) sheets of glass with pictures superimposed on them. The individual levels act as transparent glass pictures that can be edited individually. Due to the transparent areas of the individual levels, the levels below remain visible.

For example, a layer is placed on a basic image, which is used as a background, on which a lettering can be created. Because the layer is transparent like a film, the background image and the lettering appear to the viewer as a single image.

The level technique is often used in advertising agencies. So you can click on a background image, e.g. B. apply the skin of a human body, a tiger skin or a zebra skin to achieve an alienation effect.

Collages are also possible with the layer technique. For example, a palm beach is selected as the background image, a transparent film (layer) is placed on it and a beach chair, for example, is inserted on this layer. For example, a child playing can be inserted on a new layer slide, a dog again on a new slide and an advertising slogan on another slide. These elements can also be moved freely later.

The level technique can be used in many ways - the principle always remains the same. The lowest layer in the layer stack (layer palette) is called the background layer and is not changed by actions on other layers, but serves as the basis for editing. A new layer is created from the background image using a copy. At this new level you can let your creativity run free. In addition to the normal image layers, there are a number of other types of layers, each of which has special tasks.

The formula for alpha blending can be defined for each layer (except for the background layer) . For example, you can set the pixels of a plane to only be used when they are brighter, or to only use the brightness of a plane.

At the end of the work, all layers can be combined to form one image or the image and the layers can be saved in an appropriate file format (e.g. PSD). The latter allows you to make the adjustments made possible by levels later.

Advantages of the layer technique

  • The individual levels can be edited independently of one another
  • You can experiment at will to achieve the desired effect
  • Individual levels can be hidden or shown
  • Colors can be changed in individual areas of an image
  • Areas can be hidden or changed within an image

Layer types

  • Raster layers
    • Image layers contain image parts and fragments in pixel form
    • Fill layers contain a color, gradient, or pattern.
  • Masks determine the opacity of the layers below based on the brightness of the respective pixel in this layer
  • Setting levels (also known as adjustment levels) are used to fine-tune, for example, the colors, saturation and brightness of layer slides below; As with mask layers, the strength of the adjustment can be set individually for each pixel
  • Layer groups group layers, e.g. B. to limit the range of masks and adjustment levels to the other levels of the group or to combine levels with the normal blending algorithm before using a special alpha blending
  • Vector layers stay crisp as you enlarge the image, as they describe shapes that can be calculated for any image size
    • Text layers are used to create vector-based text elements
    • Shape layers are used to create vector-based shapes

The distinction between the subtypes of raster and vector layers is not made in every program. Also, not all layer types are found in all programs.

Popular programs that master layer technique

literature

  • Angela Wulf: Photoshop Elements 4.0: The Master Class . Munich: Markt + Technik, 2006 - ISBN 3-8272-4053-0 .
  • Heico Neumeyer: Adobe Photoshop CS2 Compendium: Pixel perfection from retouching to assembly . Munich: Markt + Technik-Verl., 2006 - ISBN 3-8272-4075-1 .
  • Matt Kloskowski: Photoshop Layers . Munich: Addison-Wesley 2008, ISBN 978-3-8273-2725-3

Web links