In the first installment of this series, we
looked at how layer blending options work. In this column,
we'll look at some of the basic applications of these
techniques, ideas that can be great time savers.
Of course, you can use layer blending
options to fade one layer into another. In this first
example, Dunes.tif (from Photoshop 6's Samples folder) was
used as the background. Ducky.tif (also from Photoshop 6)
was added. The dunes themselves were selected (using Color
Range) and copied to their own layer.
We'll hide the upper dunes layer and use
layer blending options to eliminate the white background for
Ducky. Because the background is almost exclusively white,
we can simply move the right slider labeled This Layer to
254. We can hold down the Option key (Alt for Windows) and
split the slider to reduce the anti-aliasing and eliminate
shadows. (More on this technique below.)
When we make the upper layer visible again,
you'll see that we must put the lower part of the duck
behind the foreground of the dunes.
When we make the copied dunes visible again,
the lower part of the duck is, indeed, hidden.
Unfortunately, so is much that needs to remain visible.
By adjusting the blending options for Layer
2, we can make the highlights invisible, leaving the
shadowed foreground intact.
(If we hide the background layer, we'll see
that the extreme blending setting hid much more of Layer 2
that necessary, but because that layer was simply a copy of
the background dunes, it doesn't matter.)
The same image of a rubber duck riding the
waves of sand could have been accomplished by simply using
the Lasso to select and delete the area of the ducky that
overlapped with the foreground of the dunes. However, using
blending options is a non-destructive technique, retaining
the original pixels for any later changes or adjustments.
When preparing the ducky image above, we hid
the background using layer blending options. In this
example, we'll use PhotoSpin's image #0490071. (The
Background layer has been converted to a regular layer by
Option/Alt-double-clicking the layer in the Layers palette.)
Simply sliding the upper-right slider from
255 to 254 seems to have eliminate the white background.
However, if we add a layer filled with black
below, we can see the anti-aliasing left behind.
By the time the sliders have been adjusted
enough to eliminate the fringe, some of the image's
highlights might also be lost.
Another thing to keep in mind when hiding a
background with layer blending options is that the pixels
are actually still there, just not visible. This can be
important when making a selection. In the following image,
the command Image> Canvas Size was used to expand the image
without changing the dimensions of the existing layers. The
apple layer's thumbnail was Command-clicked [Windows:
Control-click] in the Layers palette. Notice that the
selection border still includes the white background,
although it is not visible.
A third example uses a pair of images from
PhotoSpin, #0490057 (skull) and #0490089 (teeth). We'll show
how to use layer blending options to get a jump-start on
cleaning up parts of an image.
Some work with the Transform commands scales
and positions the teeth where they need to be.
Now we'll use layer blending options to
eliminate the bulk of the red plastic.
The Eraser tool can now be used to clean up
the remaining unwanted pixels.
