By Steve Bain
Digital camera photos and scanned images usually have a rectangular shape. This is fine if the shape fits your project. But if what you really want is a non-rectangular photo shape, you need to create a floating photo object.
In this tutorial, you’ll learn how to use Corel® PHOTO-PAINT® to select portions of your rectangular photos and save them as non-rectangular floating photo objects – the kind that allow the underlying background area to show in areas where no photo image exists. You’ll also learn how to use them in layout-capable programs such as CorelDRAW®, Corel Ventura®, Adobe® InDesign®, or QuarkXPress®.
Creating a Photo Object Selection
To save a portion of a digital photo as a photo object, you first need to isolate the element you want by making a selection. In the days of manual layout, this task was traditionally referred to as close-cropping. The mask essentially hides the unwanted area, leaving only the isolated element of interest visible. You define masks by making a selection. You can also store the current selection mask as an alpha channel automatically, or manually as a specifically named channel.
NOTE: This technique uses standard masking principles which apply in virtually any recent version of PHOTO-PAINT. Although my demonstration here uses version 12, both older and newer versions of the program can be used.
To create the photo object selection, follow these steps:
- Open the image that includes the object you would like to make into a photo object in Corel PHOTO-PAINT.
- Define a mask (selection) area. You can use any of the selection tools available in Corel PHOTO-PAINT (see below).
- If you’re new to using the selection tools in Corel PHOTO-PAINT, check out the tutorial on Mastering the Power of Selection. In the example below, a mask selects all but the background portion of an insect photo. The mask essentially hides the background and isolates the insect.
- Here’s the step where many users get confused. After you define the mask, immediately save the image (Ctrl+S) in either the CPT or TIF file formats. By saving the image with the selection mask active, you automatically save the mask as an alpha channel.
The steps above let you save your photo object without losing any pixel information from the image. However, you may want to eliminate the unwanted area completely and save only the selection as a masked object. The following alternative technique is especially useful when you only want to use only a tiny portion of a very large image:
- With your image open, isolate the area by making a selection.
- Copy the selected area to the Clipboard by choosing Edit > Copy (Ctrl+C).
- Paste the Clipboard contents as a new document by choosing File > New from Clipboard (Ctrl+Shift+N). Your selection is pasted into a new image file that has the same dimensions as those of the selection (see below).
- Save the image in CPT or TIF format, using a unique name.
Storing Multiple Object Selections in a Single File
If you want, you can store multiple selections in a single file. The selections you store will be available only to applications that are capable of reading multiple alpha channels in a single file (a capability built into QuarkXPress). Having the ability to store multiple alpha channels in a single image enables you to isolate different portions of the same imported image (see below).
To store a selection mask as an alpha channel in Corel PHOTO-PAINT, follow these steps:
- Open your image in Corel PHOTO-PAINT, and select the first area of the image you wish to make into a photo object.
- Choose Mask > Save > Save as Channel. The Save Mask as Channel dialog box opens (see below).
- Enter a unique name for your alpha channel, and click OK to save the selection.
- Select a different area of your image to save as a photo object, and choose Mask > Save > Save as Channel to open the dialog box again.
- Give your new alpha channel a unique name, and click OK to store the channel.
- To review the channels you have saved with your image, open the Channels docker by choosing Window > Dockers > Channels (Ctrl+F9). Below the default channels listed in the docker, you’ll see a list of your saved alpha channels with previews of the selection shape (see below).
Using Photo Objects in CorelDRAW and PHOTO-PAINT
Alpha channels are essentially stored selections that can be used for a number of purposes that are supported by certain file formats. In the previous steps, we specified CPT and TIF as the file formats to use when saving your photo object. The format you choose depends on how you plan to use your photo object. Either format is fine, however, if you plan to use it in another Corel PHOTO-PAINT image file or to import it into CorelDRAW.
When copied or imported into a different Corel PHOTO-PAINT image, a photo object behaves separately from the rest of the image. While the object is selected, you can apply filters or effects to it without affecting the rest of the image, as with the drop shadow applied in the example below.
When a CPT or TIF file is copied or imported into CorelDRAW, the selection that was in progress when the image was saved is automatically applied as a transparency mask – sometimes referred to as a soft mask. The selected area becomes visible, and the masked area becomes transparent. With CorelDRAW, a transparency mask applied to a photo object lets you apply effects such as drop shadows to the image. The shadow shape matches the shape of the isolated area instead of the bounding box of the entire image, as is the case when you simply import a bitmap image.
In the example below, an image of a swimming turtle has been isolated from its background by using a selection mask saved with the image. After the image was imported into CorelDRAW, a drop shadow was applied to the photo object. Notice that the transparency mask lets objects in the background remain visible.
It may also help to know that the CorelDRAW Graphics Suite ships with a collection of photo objects saved in native CPT format, which you can experiment with or use in your own projects (as in the examples below). You’ll find the collection on your CorelDRAW Graphics Suite discs 3 (typically on Disc 3 in the Objects folder), organized by category.
Working Outside the Box
If you plan to use your photo object in a layout program such as Corel Ventura®, or a third-party application such as Adobe® Illustrator®, Adobe InDesign, or QuarkXPress, the best file format in which to prepare your photo objects is TIF. The TIF format enables you to store one or more alpha channel selections in a single file. Most layout applications usually apply single stored alpha channels automatically when images are imported. Certain other applications (for example, QuarkXPress) are capable of reading multiple alpha channels in a single file.
Both Adobe InDesign and QuarkXPress use the term clipping path to refer to the transparency masks in an imported bitmap. Both applications enable you to define the clipping path for an imported image by using the alpha channel stored with the image. As mentioned earlier, QuarkXPress can read multiple alpha channels when applying a clipping path to an image.
However, even the latest version of InDesign can read only the default alpha channel that existed when the file was saved as the clipping path. To apply a stored alpha channel in InDesign, follow these steps:
- Choose File > Place to import the TIF image containing the alpha channel selection into InDesign. If the image to import includes only a single alpha channel that was in progress when the image was last saved as a TIF image, the alpha channel may already be applied. If not, proceed to the next step.
- With the imported image selected, choose Object > Clipping Path to open the Clipping Path dialog box.
- Choose Alpha Channel from the Type menu, specify any additional settings in the dialog box (see below), and click OK to apply the clipping path.
In QuarkXPress, you can apply alpha channels as clipping paths by following these steps:
- With a Picture Box selected, choose File > Get Picture to import your saved TIF image containing one or more alpha channel selections.
- With the image imported and selected, choose Item > Clipping to open the Modify dialog box to the Clipping page.
- From the Type menu, choose Alpha Channel, and use the Alpha menu that contains the specific channel you wish to use (see below). To choose from a selection of saved alpha channels in earlier versions of QuarkXPress (such as version 4 or 5), the names may be listed as Channel 1, Channel 2, Channel 3, and so on.
- Click OK to apply the alpha channel as a clipping path.
The beauty of using predefined alpha channels as clipping paths in layout applications is that they can be applied instantly, eliminating the struggle with crude clipping path editing and drawing tools.
Steve Bain is an award-winning illustrator and designer, and an author of nearly a dozen books, including CorelDRAW®: The Official Guide.