DATELINE: January 1999 Issue
Three Programs Go Far Beyond Photoshop’s Masking FunctionsBy Ben Long
Creating masks can be one of the most difficult parts of altering an image. Fortunately, several programs can help. Two, Extensis Mask Pro 2.0 and Chroma Graphics’ EdgeWizard, are Adobe Photoshop plug-ins. The third, Ultimatte KnockOut, is a stand-alone program that works with Photoshop files.
Each program uses a different approach to masking. Mask Pro 2.0 is a general-purpose masking utility, offering a variety of intelligent brushes and tools that let you paint masks into an image. KnockOut shines at creating difficult masks that involve wisps of hair, complex shadows, and translucent elements. EdgeWizard lacks its own masking tools, but it lets you refine the edge of an existing selection created in Photoshop or another program (including Chroma Graphics’ MagicMask plug-in).
Of the three, Mask Pro offers the widest range of masking tools. Similar to Photoshop’s QuickMask feature, it lets you select colors to keep and drop using two special eyedroppers. When you paint with Mask Pro’s brushes, the plug-in analyzes the colors beneath your brush, compares them with your selected colors, and applies an appropriate level of transparency to the mask.
A new IntelliBrush tool automatically selects Keep and Drop colors by averaging the pixels beneath the brush. This makes it easier to create complicated masks; without it you would have to make many manual color selections.
Mask Pro can automatically knock out image layer backgrounds, and its pen tool can now automatically detect edges and set control points accordingly. A new, separate EdgeBlender plug-in blends semitransparent pixels with background pixels to reduce halos.
Mask Pro is powerful, but it still can take a lot of time to mask wisps of hair or translucent objects. That’s where KnockOut comes in. You create a mask in KnockOut by using four lasso tools to trace outlines along the boundaries of the area you want to select. The first traces inside the area to be masked; the second, around the outside (see “Hair Today”). Two similar tools let you create inner and outer boundaries for any shadows you want to mask.
KnockOut’s Process Image feature then generates a mask, which you can refine using the Syringe or Edge Feather tools. Syringe tools let you inject color into pixels that are being rendered transparent; the Edge Feather tool lets you define edges in areas where there’s little difference between the foreground and background.
KnockOut’s results are impressive, but the program cannot soften mask edges, and it lacks tools for manually refining the mask. It’s also a memory hog-you need at least five times as much RAM as the maximum image size-and it uses a dongle.
EdgeWizard’s edge-refining tools can automatically eliminate halos and transparency problems. After you create a mask, the plug-in provides a preview of your image and the selection. You can then modify the mask edge in three ways: QuickEdge applies a two- or three-pixel blur, producing a result similar to feathering. Gaussian Edge applies a Gaussian blur, creating even blends in images that have simple backgrounds. Variable Color Edge, for use with complex selections, analyzes colors along the edge to determine the best way to blend with the background. All three effects can be brushed in or applied globally.