Photoshop Elements > Retouching >
2 - Smooth Skin Explained
This section will explain how the skin is smoothed.
For reference, here's the chart and Layers panel (Layers palette) from the last
section.
| Lighten / 30% Opacity |
Top |
Lighten |
30% |
| Darken / 40% Opacity |
Middle |
Darken |
40% |
| Background |
Bottom |
– |
– |
Here's a 1600% enlargement of a mole on a cheek.
A mole on a cheek is used here, rather than just a cheek, because
its pixels are more visible.
The smooth-skin technique, of course, doesn't retouch moles.
The middle layer was copied below from the Background layer.
|
Middle Layer
|
 |
|
Background
|
|
Gaussian Blur
The blurring of the middle and top layers shifts the pixels in
these layers slightly.
The pixels in these two layers are no longer in register with
the Background layer.
This difference allows the blending modes, Darken and Lighten,
to create the smooth-skin effect.
Below, the middle layer is blurred.
The Background layer is not visible, because the opacity of the
middle layer is 100%.
|
Middle Layer
Opacity 100%
|
 |
|
Background
|
|
The final image is both sharp and blurred.
The opacity of the middle layer is changed to 40%.
Now, 60% of the non-blurred Background layer becomes visible.
The image you see on your monitor, the middle layer below, contains
the following.
• 40% of the middle layer
• 60% of the Background layer
|
Middle Layer
Opacity 40%
|
 |
|
Background
|
|
Stop Here?
Many people stop at this point.
However, the Darken and Lighten blending modes improve the skin
smoothing.
Darken Blending Mode
Next, the blending mode of the middle layer is changed to Darken.
The Darken blending mode compares the pixels in the middle layer—and
in the Background layer.
The pixels that are darker in either of the two layers are selected
and displayed.
That is:
• Pixels that are lighter in the middle layer, than in the Background
layer, are darkened.
• Pixels that are darker already, in the middle layer, than in
the Background layer, remain the same.
Not literarily, but one can think that the darker colors are
being smeared slightly by the blending mode.
|
Middle Layer
Opacity 40%
Darken Mode
|
 |
|
Background
|
|
Lighten Blending Mode
Next, the top layer's blending mode is changed to Lighten.
The RGB values of the middle layer pixels are compared to the
RGB values of the corresponding pixels in the Background layer.
The pixels that are lighter in either of the two layers are selected
and displayed.
That is:
• Pixels that are darker in the top layer, than in the middle
layer, are lightened.
• Pixels that are lighter already, in the top layer, than in
the base layer, remain the same.
The image you see on your monitor is the top layer below.
|
Top Layer
Opacity 100%
Lighten Mode
|
 |
|
Middle Layer
Opacity 40%
Darken Mode
|
|
|
Background
|
|
Then, the opacity of the top layer is changed to 30%.
Now, the image you see on your monitor, the top layer below, contains
the following.
The image you see on your monitor, the middle layer below, contains
the following.
• 30% of the top layer
• Portions of the middle layer and the Background layer
|
Top Layer
Opacity 30%
Lighten Mode
|
|
|
Middle Layer
Opacity 40%
Darken Mode
|
|
|
Background
|
|
Below, the cheek is at 100% magnification.
Again, the mole was used as an example for visibility of the
pixels.
The smooth-skin technique doesn't retouch moles.
Note how the . . .
• Blotches on the cheek under the mole have disappeared.
• Film grain, evident at the edge of the face to the right, is
subdued.
Original
Smoothed
To learn more about the Darken and Lighten blending modes, and
if you know your way around blending modes, go to
Darken and Lighten.
If you're new to blending modes, go to
Blending Modes.
