Combining multiple images together to create a single merged image is called compositing, and the possibilities for compositing are endless. You can combine different digital photos or scanned images to create effects that range from subtle to spectacular to silly. For example, you can replace a landscape's clear blue sky with a dramatic sunset, create complex, multilayered photo collages, or replace the face of the Mona Lisa with that of your Uncle Harold. We'll explore just a few of the ways you can composite images with Photoshop Elements.
Photoshop Elements lets you combine pictures in ways that would be difficult or even impossible to accomplish in the darkroom. The selection tools let you isolate the parts of an image you want to use, and the Layers palette provides a powerful and elegant tool for combining and merging different image elements. Although you can do some compositing without the aid of the Layers palette (cloning parts of an image from one file to another, for example), layers give you much more flexibility to move and adjust and modify one area of an image while leaving other areas untouched.
In the following example of an image for a travel agency brochure, we want the composite image to look as if it were an original unretouched photograph.
To replace part of an image with another image
Open an image that contains an area you want to replace.
We'll call this the "target" image.
In the example, the sky isn't very interesting, and we want to add a more dramatic background (Figure 12.73). Even though the sky and the ship are both blue, the edges are well defined, so the image is a good candidate for the Background Eraser tool.
Figure 12.73. We'll enhance this image by replacing its lackluster background.
From the toolbox, select the Background Eraser tool; then adjust its brush size and tolerance values.
We set the tolerance value fairly low because the sky and the ship both contain a lot of blue. If we set the tolerance value higher, a broader range of pixels may be selected, and some parts of the ship might be erased. (For more information on using the Background Eraser tool, see "Erasing Backgrounds and Other Large Areas" in Chapter 8, "Painting and Drawing.")
Position the Background Eraser tool along the outside edge of the foreground shape (the ship). Making sure that the brush crosshairs are over the background (sky), drag along the edge to erase the background. Continue to erase the background until the area is completely transparent (Figure 12.74).
Figure 12.74. Use the Background Eraser tool to remove the sky and create a transparent background.
Open the image that you want to use to replace the transparent pixels in your original image.
We'll call this the "source" image.
Select the Move tool and drag the source image into the target image (Figure 12.75).
Figure 12.75. Drag the source image (the sky) into the target image (the ship).
In the example, the sky image is larger than the empty background area, which allows flexibility in positioning the new sky in the composition.
If you like, you can also use the selection tools to select just a portion of the source image, then drag just that selection into the target image.
On the Layers palette, drag the source layer below the target layer (Figure 12.76).
Figure 12.76. Move the sky layer below the ship layer on the Layers palette and adjust the position in the image window.
In the image window, use the Move tool to adjust the position of the source image until you're satisfied with the composition.
If you want, you can use the image adjustment tools on each layer to create a more natural-looking composition.
Creating whimsical composite images
In many cases, as in the previous example, you composite images to improve them in a way that isn't obvious to the viewer. You don't want to draw attention to your work; you just want to improve the image (as in the ship and sky example). But sometimes you want your audience to wonder how you created that cool special effect. This composite for an elementary school astronomy fair poster is an image that looks pretty realistic, if a little fantastical (Figure 12.77). (See the color plate section of this book for a full-color view of this task.)
Figure 12.77. This final composite image was created from two separate images.
To combine images
Open two images that you want to composite (Figure 12.78).
Figure 12.78. Here, I used a picture of a boy and a photograph of space to create an otherworldly image.
Use the selection tools and/or eraser tools to isolate part of the source image.
In this case, we'll use the Background Eraser tool to erase the background from the boy, leaving the area around him transparent (Figure 12.79). This way, he'll insert nicely into the target image, with no messy halos or edges around his body.
Figure 12.79. Use the Background Eraser tool (or any other selection tool) to isolate your source image.
Copy the area of the source image that you want to composite.
Paste that selection into the target image (Figure 12.80).
Figure 12.80. After pasting the source image (the boy) into the target image, the source image is placed on a new layer above the target image. That makes it easy to drag the image of the boy into its proper position.
This creates a new layer.
Using the Move tool in the image window, position and resize the source image (top layer) to match the target image (bottom layer).
If you like, you can add layer styles to enhance the image.
In this example, I chose the Low option in the Drop Shadow section of the Layer Styles palette to create an effective drop shadow on the boy's hand (Figure 12.81).
Figure 12.81. The original composite lacked a little realism (left), so I added a drop shadow layer effect below the boy's hands (right) to complete the effect.
Creating new composite images
In the previous examples, we simply combined different objects we'd photographed in order to enhance those objects. In these types of compositions, the source images (the ship and little boy) were still recognizable; they were just composited into new backgrounds or environments.
A second compositing technique combines digital photos or scanned objects to create something entirely new, and in the process the individual replacement images used become barely recognizable. (A classic example of the old adage, "the whole is better than the sum of its parts.") In the next example, we'll combine multiple layers to create a collage for a quilting Web site (Figure 12.82). We'll use the Custom Shape tool to create a layer group, and then we'll apply layer styles to a text layer.
Figure 12.82. This image is a composite of two image layers: a shape layer and a text layer with layer styles applied.
To create a layered photo collage
Open the two images you want to combine (Figure 12.83).
Figure 12.83. Open the images you want to composite.
We're going to combine scans of two contrasting fabrics to create the look of a quilt.
Select the Custom Shape tool and choose a shape from the menu on the options bar.
I chose the Tile 4 option, since it looks like a diamond quilt pattern (Figure 12.84).
Figure 12.84. Select a custom shape that you'll use to define the shape of one of your composite layers.
In the background image file, drag the Custom Shape tool to create the shape pattern. Hold down the Ctrl key and drag inside the shape to reposition it if necessary.
A new layer with the shape is created (Figure 12.85).
Figure 12.85. Draw the Custom Shape so that it fills a large portion of the image window.
Now we'll use the shape to create a mask for the other fabric layer.
Copy and paste the foreground image into the Background image file.
The foreground image creates a new layer in the Background image file, immediately above the shape layer we just created (Figure 12.86).
Figure 12.86. Paste the layer you want to composite above the custom shape layer.
Make sure that the foreground image is selected; then, from the Layer menu, choose Group with Previous, or press Ctrl+G.
A layer group is created. The foreground image now shows only within the area of the custom shape below it. The fabrics look as if they have been quilted together in a pattern (Figure 12.87).
Figure 12.87. When you create a layer group, the bottom layer acts as a mask, allowing the layer above to show through only those areas in the bottom layer that are opaque.
Select the Text tool, then click in the image and enter your text.
Select the Move tool and position the text if necessary.
For this example, I used a bold type face and set the text color to white (Figure 12.88).
Figure 12.88. Create a new text layer on top of the other layers.
With the text layer selected on the Layers palette, choose a layer style from the Styles and Effects palette.
I chose Simple Pillow Emboss from the Bevels styles (Figure 12.89).
Figure 12.89. Choose an Emboss option from the Bevels styles in the Styles and Effects palette.
From the Library drop-down menu on the Styles and Effects palette, choose Visibility.
Select the Ghosted option (Figure 12.90).
Figure 12.90. Choose an option from the Visibility styles in the Styles and Effects palette.
The text looks like it has been quilted into the fabric.
To make further adjustments to the embossing effect, click the Layer Style icon on the text layer on the Layers palette.
The Style Settings dialog box appears, where you can make adjustments to the Layer style you have applied (Figure 12.91).
Figure 12.91. Use the Style Settings dialog box to adjust your layer styles.