InDesign for QuarkXPress Users [Electronic resources] نسخه متنی

Creating Clipping Paths

If you import an image without an embedded clipping path, you can ask InDesign to create one using the Detect Edges option, which is similar to QuarkXPress's Non-white Areas clipping path feature. You can use this feature to drop out a solid colored (white or near-white) background behind an image. After selecting an image to clip and choosing the Clipping Path command from the Object menu, choose the Detect Edges option from the Type popup menu in the Clipping Path dialog box.

With the Detect Edges option selected, you can determine how close to the color white a pixel must be before it is ignored and removed from the visible area with the Threshold control (see Figure 68-2). Lighter backgrounds require a lower threshold whereas darker images require a higher value. The Tolerance setting determines how different a pixel is from the Threshold value for it to be recognized in creating the clipping path. Finally, the Inset Clipping Path choice lets you shrink the resulting clipping path, often to remove a white fringe around the image.

If the image has an extra channel in it, you can also tell InDesign to base the clipping path on it by choosing Alpha Channel from the Type popup menu in the Clipping Path dialog box. In this case, anything 50-percent black or darker in the channel is outside of the path.

In general, we usually shy away from using either the Detect Edges or the Alpha Channel features except perhaps for a quick comp. They're just too clunky.