|
|
What does this image
of cherry blossoms have in common with the carved relief on the left?

The carving, and
the image, both have a finite resource called depth. In the case of
the sculpture, the depth is the physical depth of cut of about a centimeter.
For the image, the limit is the bit depth of the pixel data value: 24 bits,
or 8 bits per channel of red, green, and blue.
The
artist who carved the representation of "Jacob's Ladder" on the
left faced many of the same constraints and goals that we do when we color
correct an image, and the solutions he employed in solving them may be directly
translated to our work in color correcting an image.
|
| |
In our bas-relief
image of Jacob, the stone carver has a limited "depth" of stone
to work with, and has chosen to allocate this precious resource to the diagonal
structure of the ladder and its rungs, and less to facial features and textures.
By analogy, it
is wise to apply a similar strategy when allocating the bit "depth"
available to us in a photograph.
Specifically, if
we want to imitate the art of the sculptor, we should be very careful how
we allocate the color gamut of an image to best represent the subject of an
image. This means suppressing the insignificant parts of the image to achieve
our goal of pleasing the eye. If in making the cherry blossoms of Example
2 stand out better, we knock the leaves down to a lower saturation, so be
it.
In an analogous
way, a skilled color corrector can analyze how much of a particular color
range is being used by the subject of an image, and carefully allocate more
color range to that part of the image, stealing it from the leaves in the
background, for example, and giving it to the flower itself - the part the
eye "cares" about.
|