Magic Eraser, Background Eraser, Art History Brush
Dateline: 11/03/99
Magic Eraser Tool 
The magic eraser tool works similarly to the magic wand tool that most users
will be familiar with. The difference is that the magic wand tool selects pixels
based on color similarity, while the magic eraser tool removes those pixels
leaving behind a transparent area.
The
tools options are shown here. Tolerance controls the number of colors that are
deleted according to their similarity of the color that is clicked on. A lower
setting will erase colors that are closer in color to the pixel that is clicked
on, a higher number will eraser a wider range of colors in relation to the color
that is clicked on. In the two examples below, the first image had a tolerance
setting of 50, while the second image had a tolerance of 100. If you set the
tolerance too high, however, you'll start to loose parts of the image you want
to keep.
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As
you can see, you can get quite good results by making adjustments to the tolerance
settings. The opacity setting controls the transparency of the erased area.
The third example to the right shows the results of the same image using the
magic eraser with the opacity set to 50%.
The use all layers option samples the colors from all visible layers in the image. Anti-aliased blends the edges of the erased area. Checking the contiguous option causes only areas contiguous to the selected pixels to be erased. Unchecking this option will remove similar colors throughout the image.
Background
Eraser 
The background eraser removes the background colors from an image by dragging
over the image with a brush. This works well when the image has a variation
of colors in the background. In the example image here, I was able to isolate
the flower by using the background eraser (shown in the second image), then
it was easy to lasso around the flower to erase the remaining background, resulting
in the third image.
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The
options used are shown here. The first drop down box offers eraser options for
Discontiguous, Contiguous, or Find Edges. The Sampling drop down offers the
choice of Continuous, Once, or Background Swatch. These options are all explained
very well in the Photoshop 5.5 User Guide Supplement.
Art
History Brush 
The Art History Brush lets you apply paint styles to your image using
a history state or snapshot as the source. The options include various blending
modes, opacity, paint stroke style, fidelity, area, and tolerance.
The
various paint stroke options are shown in the menu to the right. This tool takes
some experimentation to see the variety of effects that can be achieved.
In my example I used the Art History brush to paint swirls in the background area of my image, muting the background details and bringing the focus to the subject of the photo.
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Contiguous Option
The contiguous option has been added to the Magic Wand and Paint Bucket tools
as a new feature in Photoshop 5.5. This option works just as it does in the
magic eraser tool discussed above, increasing the functionality of these tools.
Return to the Introduction/Table of Contents.
Go to the Next Page: Extract Command
Also see: Photoshop Resources
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Sue Chastain |
Screen shots captured with Corel Capture 9. Example images from Nova Development's Art Explosion 600,000.
