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Extract an object from its background
 To more effectively extract
objects from backgrounds, use the Refine Edges option for selection
tools. (See Refine selection edges.) If you prefer the optional Extract plug-in
described below, download it for Windows or Mac OS. The
Extract filter provides a sophisticated way to isolate a foreground
object and erase its background on a layer. Even objects with wispy,
intricate, or undefinable edges may be clipped from their backgrounds
with a minimum of manual work. You use tools in the Extract dialog
box to specify which part of the image to extract.
 For
simpler cases, try using the Background Eraser tool. When
you extract the object, Photoshop erases its background to transparency. Pixels
on the edge of the object lose the color components derived from
the background, so they can blend with a new background without
producing a color halo.
 Selected area highlighted and filled, and extracted object  You can add back opacity to the background and
create other effects using the Edit > Fade Extract command
after an extraction.
- In
the Layers palette, select the layer containing the object you want
to extract. If you select a background layer, it becomes a normal
layer after the extraction. If the layer contains a selection, the
extraction erases the background only in the selected area.
 To
avoid losing the original image information, duplicate the layer
or make a snapshot of the original image state.
- Choose
Filter > Extract, and then specify tool options:
- Brush Size
- Enter a value, or drag the slider to specify the width
of the Edge Highlighter tool
. You
also use the Brush Size option to specify the width of the Eraser,
Cleanup, and Edge Touchup tools. - Highlight
- Choose a preset color option for the highlight that appears
around objects when you use the Edge Highlighter tool, or choose
Other to pick a custom color for the highlight.
- Fill
- Choose a preset color option, or choose Other to pick
a custom color for the area covered by the Fill tool.
- Smart Highlighting
- Select this option if you are highlighting a well-defined edge.
The option helps you keep the highlight on the edge, and applies
a highlight that is just wide enough to cover the edge, regardless
of the current brush size.
Note: If you use Smart Highlighting
to mark an object edge that’s near another edge, decrease the brush
size if conflicting edges pull the highlight off the object edge.
If the object edge has a uniform color on one side and high-contrast
edges on the other side, keep the object edge within the brush area
but center the brush on the uniform color.
Specify Extraction
options: - Textured Image
- Select this option if the foreground or background of
your image contains a lot of texture.
- Smooth
- Enter a value or drag the slider to increase or decrease
the smoothness of the outline. It’s usually best to begin with zero
or a small value to avoid unwanted blurring of details. If there
are sharp artifacts in the extraction result, you can increase the
Smooth value to help remove them in the next extraction.
- Channel
- Choose the alpha channel from the Channel menu to base
the highlight on a selection saved in an alpha channel. The alpha
channel should be based on a selection from the edge boundary. If
you modify a highlight based on a channel, the channel name in the
menu changes to Custom. Your image must have an alpha channel for
the Channel option to be available.
- Force Foreground
- Select this option if the object is especially intricate
or lacks a clear interior.
- Select the Edge Highlighter tool
, and
draw to define the edge of the object you want to extract. Drag
so that the highlight slightly overlaps both the foreground object
and its background. Use a large brush to cover wispy, intricate
edges where the foreground blends into the background, as with hair or
trees.  Use either the Zoom tool or the Hand tool
to adjust the view as needed. If you need to erase the
highlight, select the Eraser tool , and
drag it over the highlight. To erase the entire highlight, press
Alt+Backspace (Windows) or Option+Delete (Mac OS).
If
the object has a well-defined interior, make sure the highlight
forms a complete enclosure. You do not need to highlight areas where
the object touches the image boundaries. If the object lacks a clear
interior, highlight the entire object.
Note: You
can’t highlight the entire object if you’ve selected Textured Image
or Force Foreground.
- Define the foreground area by doing one of the following:
If
the object has a well-defined interior, select the Fill tool . Click
inside the object to fill its interior. Clicking a filled area again
with the Fill tool removes the fill.
If you’ve selected Force Foreground, select the
Eyedropper tool , and
click inside the object to sample the foreground color, or click
in the Color text box and use a Color Picker to select the foreground
color. This technique works best with objects that contain tones
of a single color.
- (Optional) Click Preview to preview the
extracted object. Zoom in as needed.
- Show
- Choose a menu option to switch between views of the original
and the extracted image.
- Display
- Choose a menu option to preview the extracted object
against a colored matte background or a grayscale background. To
display a transparent background, choose None.
- (Optional) Improve the extraction by doing one of the
following:
Choose new Highlight and Fill options and
draw again with the Edge Highlighter tool. Define the foreground
area once more, and then preview the extracted object.
Specify new Extraction settings (Smooth, Force Foreground,
or Color) and then preview the extracted object.
When you are satisfied with the extraction, you can do
the final touchups.
- Touch up the extraction results by doing one of the following:
To erase background traces in the extracted
area, use the Cleanup tool . The
tool subtracts opacity and has a cumulative effect. You can also
use the Cleanup tool to fill gaps in the extracted object. Hold
down Alt (Windows) or Option (Mac OS) while dragging to
add back opacity.
To edit the edge of the extracted object, use the
Edge Touchup tool . The tool
sharpens edges and has a cumulative effect. If there is no clear
edge, the Edge Touchup tool adds opacity to the object or subtracts
opacity from the background.
 You can also clean up the image after an
extraction by using the Background Eraser and History Brush tools
in the toolbox.
- Click OK to apply the final extraction. On the layer,
all pixels outside the extracted object are erased to transparency.
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