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Importing and Exporting Paths

Paths come in handy not only for working in Photoshop, but also for importing images into drawing programs, such as Illustrator and FreeHand, and into page-layout programs, such as InDesign and QuarkXPress. By saving a path as a clipping path, you can mask regions of an image so that it appears transparent when placed in other programs that support clipping paths.

In addition, you can swap paths directly with the most recent versions of Illustrator and FreeHand. That way, you can take advantage of the more advanced path-creation features found in those programs. You can even copy and paste paths into After Effects for use as masks or even motion paths.

The last few sections of this chapter explain some of these added uses for your Photoshop paths.

Swapping paths with Illustrator

You can exchange paths between Photoshop and Illustrator or FreeHand by using the Clipboard. This special cross-application compatibility feature expands and simplifies a variety of path-editing functions.

Suppose that you want to scale and rotate a path. Select the path in Photoshop with the black arrow tool and copy it to the Clipboard by pressing Ctrl+C (z -C on the Mac). Then switch to Illustrator, paste the path, and edit as desired. About 95 percent of Illustrator's capabilities are devoted to the task of editing paths, so you have many more options at your disposal in Illustrator than in Photoshop. When you finish modifying the path, copy it again, switch to Photoshop, and paste.

When you paste an Illustrator path into Photoshop, the dialog box shown in Figure 8-41 gives you the option of rendering the path to pixels (just as you can render an Illustrator EPS document using File Open), keeping the path information intact, or creating a new shape layer. Select the Paths radio button to add the copied paths to the selected item in the Paths palette. (If no item is selected, Photoshop creates a new Work Path item.) You can then use the path to create a selection outline or whatever you want.

Figure 8-41: When pasting a path copied from Illustrator, Photoshop greets you with this dialog box.

Exporting to Illustrator

If you don't have enough memory to run both Illustrator and Photoshop at the same time, you can export Photoshop paths to disk and then open them in Illustrator. To export all paths in the current image, choose File Export Paths to Illustrator. Photoshop saves the paths as a fully editable Illustrator document. This scheme enables you to trace images exactly with paths in Photoshop and then combine those paths as objects with the exported EPS version of the image in Illustrator. Whereas tracing an image in Illustrator can prove a little tricky because of resolution differences and other previewing limitations, you can trace images in Photoshop as accurately as you like.

Retaining transparent areas in an image

Adobe's object-oriented design programs, InDesign 2 and Illustrator 10 (and later), can read transparency straight from a native Photoshop (PSD) file. However, this is hardly the norm. In virtually every other program — including the likes of QuarkXPress and FreeHand — any image file, whether it contains transparent pixels or not, comes in as a fully opaque rectangle. Even if the image appeared partially transparent in Photoshop — on a layer, for example — the pixels will be filled with white or some other color. In cases like this, you need to establish a clipping path to mask portions of an image that you want to appear transparent. Elements that lie inside the clipping path are opaque; elements outside the clipping path are transparent. Photoshop enables you to export an image in the EPS format with an object-oriented clipping path intact. When you import the image, it appears premasked with a perfectly smooth perimeter, as illustrated by the clipped image in Figure 8-42.

Figure 8-42: I drew one path around the perimeter of the skull and another around the eye socket. After defining the paths as clipping paths, I exported the image in the EPS format, imported it into Illustrator, and set it against a black background for contrast.

The following steps explain how to assign a set of saved paths as clipping paths.

STEPS: Saving an Image with Clipping Paths

Draw one or more paths around the portions of the image that you want to appear opaque. Areas outside the paths will be transparent.

Save the paths. Double-click the Work Path item in the Paths palette, enter a path name, and press Enter or Return. (Try to use a name that will make sense three years from now when you have to revisit this document and determine what the heck you did.)

Choose the Clipping Path command from the Paths palette menu, as shown in Figure 8-43. Photoshop displays the dialog box shown at the top of the figure, asking you to select the saved paths you want to assign as the clipping path. Remember, you can't make the Work Path a clipping path; you must save it as a named path first.

Figure 8-43: Choose the Clipping Path command from the Paths palette menu (bottom) and then select the path that you want to use from the Clipping Path dialog box (top).

Choose File Save As, select Photoshop EPS from the Format pop-up menu, and press Enter or Return. Select the desired Preview and Encoding settings and then press Enter or Return. Photoshop saves the EPS image with masked transparencies to disk.

Figure 8-44 shows an enhanced version of the clipped skull from Figure 8-42. In addition to exporting the image with clipping paths in the EPS format, I saved the paths to disk by choosing File Export Paths to Illustrator. In Illustrator, I used the exported paths to create the outline around the clipped image. I also used them to create the shadow behind the image. The white of the eyeball is a reduced version of the eye socket, as are the iris and pupil. The background features a bunch of flipped and reduced versions of the paths. This may look like a lot of work, but the only drawing required was the creation of the two initial Photoshop paths.

Figure 8-44: It's amazing what you can accomplish by combining scans edited in a painting program with smooth lines created in a drawing program.

Be prepared for your images to grow by leaps and bounds when imported into Illustrator. The EPS illustration shown in Figure 8-44 consumes six times as much space on disk as the original Photoshop image saved in the TIFF format.