Image Processing Reference
In-Depth Information
Fig. 3.12
Examples of pseudo color mapping
Shade
Darkening a color. When a subtractive color space is applied, different
shades (darker nuances) of a color are obtained by mixing the color with differ-
ent amounts of black.
Tint
Lightening a color. When a subtractive color space is applied, different tints
(lighter nuances) of a color are obtained by mixing the color with different amounts
of white.
Tone
A combination of shade and tint, where gray is mixed with the input color.
'(
denoted prime
) The primed version of a color, i.e., R', means that the value has
been gamma-corrected.
Sometimes a gray-scale image is mapped to a color image in order to enhance
some aspect of the image. As mentioned above a true color image cannot be recon-
structed from a gray-level image. We therefore use the term
pseudo color
to under-
line that we are not talking about a true RGB image. How to map from gray-scale to
color can be done in many different ways. In Fig.
3.12
and Fig. 2.22 examples are
illustrated.
