A little more signal effect is good for many pictures. Apart from the choice of motif, it is the color contrast , which goes a long way to being the center of attention. If the background is also shown in black and white, the colorful motif moves into the focus of the picture. This Color effect becomes color key called and was used very heavily especially by advertising. Be it a woman's red lips, a colorful flower or the typical New York yellow cab. Photo history was written with this effect.
From video to photography: Keying briefly explained
The so-called „keying“ is a technical term from video editing and an important technique to use in post-production visual effects incorporated into the imagery. In addition to simulations and animations, texting, shading and other processing steps also belong to this type of image processing. Accordingly, image compositions are created in order to reduce two images or two levels to a now changed image. Apart from Color key effect is this image change spatially using the 3D keying or chromatically with the Chroma Key implemented.
Suitable motifs to perfectly stage the color key
The 2005 film Sin City, adapted by Frank Miller from the comic of the same name, impressively shows how the color key can be implemented perfectly on film. The same applies when a photo is perfected with this editing technique. The classic of letting red lips or a red rose stand out against the dark background sets strong accents . Almost any object can be the center of attention in this way, whereby the suitable choice of color does not have to be just red. Whether yellow, green or blue, there are no limits to the imagination. Effect colors can also emerge, but these should be one good color contrast to the constant monochrome background form. Vehicles such as taxis, scooters or flowers are often used for this effect. At the same time, signs, still lifes or other objects are also popular motifs that need to be highlighted.
The implementation of the color key effect via image processing
There are different image processing steps necessary for the implementation of a color keys can be used. First will be a image editor required by the photo can be edited. In our example we show editing with Photoshop. The photo, which was initially taken in color, is then either painted with a brush monochromatically discolored or the desired colored part is marked and the Rest of image discolored . While the digital discoloration of the image with a brush is very time-consuming and tedious, marking a specific image section using an appropriate tool is usually the better method.
First of all, it is necessary two levels to create a color image and its decolorized counterpart. With a selection tool (eg lasso, magic wand, etc.) the edge of the target object can now be traced in order to separate it from the other photo areas. By releasing this selection and creating a new vector mask it is now possible to combine the monochrome background with the colored cut-out part. This time-consuming method is made a whole lot easier with the Masks path tool. This is a type of masking film in the form of grayscale images that can hide areas due to the contrast intensity.n.
Other tools, such as the Lasso tool, can also be used in these masks retouching used become.
Sometimes when using the selection tool there may be some hard edges or other areas selected. In this case, it can be reworked with a black and white brush. The white brush, in this case, colors everything black and white, while the black brush restores the colors.
It is important for this function that the layer mask (the small white box under layers) is selected.t.