Masking Unmasked- Pg2- Giordan On Graphics | 2
What is a Mask?
The masks of Batman, the Lone Ranger, and the Phantom concealed their features and identity. In image editing, masks also perform the function of concealment, hiding a part of the image.
A simple way to look at this is to think in terms of silhouetting. When you silhouette an image, you mask out its background, allowing the viewer to focus only on the central subject. In terms of composition, a silhouette lets you break away from the rigid grid-like structure imposed when square images are overused on a page. With image silos, the page opens up, creating more white space and a more interesting feel. Silhouettes are commonly used in catalogs and magazine layouts, but they also can be put to good use on a Web page.
It's a simple matter to convert a mask to a GIF89 transparent area, or even to paint a masked area the same color as the page background. Whatever approach you use, the result is the same: silhouettes create more interesting pages, on the Web and in print.
Creating a clean silhouette is probably the most common reason for cutting a mask, but you should also consider masking as a way to isolate different image areas for further editing. Maybe you want to color correct one area in an image, or perhaps blur the background. Creating a mask of just that one area helps to isolate the effect for more professional results.
In simple terms, a mask is just a fancy name for selecting a particular area. The term mask originates in the old paste-up school where frisket masks were used to block out areas that were not supposed to print.
The confusion over the term is further complicated in the various ways that the term "mask" is used by image editing applications. Photoshop has Layer Masks and Quickmask, Painter has masks, Automasks, and Floaters which are applied and used differently, and Corel has its own unique way of applying masks. Then there are the third party applications that do nothing but masking. Products like Extensis Mask Pro or Ultimatte Knockout from Ultimatte Corporation exist solely to create complex masks.
If masking is just making a selection, then why do we need so many tools? The answer is that some of them let you make selections faster and easier, and other tools deliver more flexibility with what you can do with a mask after you've created it. For example, Painter lets you activate, or invert a mask with a simple mouse click.
Since all of these products deliver a wide range of mask control, you should consider your masking requirements before deciding which products suit your needs. With a little practice you can learn to create acceptable masks for just about any image, using a standard image editor like Photoshop. On the other hand, if you create masks on a daily basis, a customized program like Extensis Mask Pro can be a real time saver.
Since I can't address all applications in this one space, I'll fall back on my standard practice of using Photoshop as a baseline example, focusing on the broad principles that can be applied to other programs.
Created: Nov. 16, 1998
Revised: Nov. 10, 1998