Page 130 - Enhancing CAD Drawings with Photoshop

4386.book Page 113 Monday, November 15, 2004 3:27 PM

EXTRACTING ENTOURAGE 113

3. Drag the lower-right corner handle of the Extract dialog box and enlarge it to fill your screen.
The size that it becomes depends on the resolution to which you have set your graphics card
(see Chapter 2, “Working with Color”).
Feel free to use the Zoom and Hand tools within the Extract dialog box at any time to navigate
the image. These tools do not interfere with any of the other tools and work identically to the
Zoom and Hand tools in the toolbox. The amount that you will have to navigate ultimately
depends on the size you are able to make the dialog box; if you have less resolution, you will
have to navigate more.
4. Start with a brush size of 35 (set in the Tool Options group) and use the Edge Highlighter tool
(press B) to trace the outer boundary of the tree’s leaves and branches. Do not worry about try-
ing to trace interior areas of translucency yet. Also, do not use Smart Highlighting on the leaves
and branches because it would be far too tedious to try to trace the edges of the myriad leaves.
Instead, focus on quickly outlining the silhouette of the tree with a larger brush size first.

TIP In general, a smaller brush size is better when using the Edge Highlighter because it produces a
smaller transition area between the object you are extracting and its background.
5. Check Smart Highlighting in the Tool Options group and proceed to trace the hard edges of
the tree trunk itself. Intentionally draw a horizontal line at the bottom of the tree trunk where
it meets the grass to create a complete highlight enclosure.

NOTE If you make any mistakes while painting with the Edge Highlighter, you have one undo (press
Ctrl+Z) while in the Extract dialog box. You can also use the Eraser tool to get rid of stray highlight-
ing; then you can go back and properly highlight the affected area.

6. Use the Fill tool (press G) and click inside the enclosure you highlighted in the previous two
steps. Figure 4.16 shows the tree with proper highlight and fill. You’ll find a version of this
image in the color section.
There is a way to help smooth out irregularities in the highlighted areas you trace. The Tex-
tured Image feature blurs the boundary between the foreground object and its background; it
is appropriate for wispy edges (such as hair) or edges with a mixing of opaque and translucent
areas (such as leaves).

NOTE You can undo a preview in the Extract dialog box by pressing Ctrl+Z. This is helpful when you
want to try a different smoothing setting and then preview again.

7. In the Extraction group, check Textured Image. Click the Smooth drop-down and increase its
value to 33. Now that you have defined the edges (with highlight) and indicated what part of
the image is the foreground object (with fill), you are ready to preview the result. Click the Pre-
view button. Your computer may take a few seconds to process this request, and then a preview
will appear as shown in Figure 4.17.