DIGITAL IMAGE MANAGEMENT AND MANIPULATION 8 Using layers Making image adjustments using layers allows image-processing operations to be applied and the results seen, without being finalized. A background layer contains the unchanged image information, and instead of changing this original information, for example, a tonal adjustment can be applied to all or part of the image in an adjustment layer. While the layer is on top of the background and switched `on' the adjustment can be seen on the image. If an adjustment is no longer required, the layer can be discarded. Selections can also be made from the image and copied into layers, meaning that adjustments may be performed to just that part of the image, or that copied part can be imported into another image. Layers can be grouped, their order can be changed to produce different effects, their opacity changed to alter the degree by which they affect the image and they can be blended into each other using a huge range of blending modes. Layers can also be made partially transparent, using gradients, meaning that in some areas the lower layers or the original image state will show through. Working with layers allows image editing to become an extremely fluid process, with the opportunity to go back easily and correct, change or cancel operations already performed. When the editing process is finished, the layers are flattened down and the effects are then permanent.