Image Processing Reference
In-Depth Information
Among these factors, space has two dimensions, however wavelength information is often
replaced and approximated by the primary colors red, green, and blue, as will be shown later;
therefore, color can be considered three dimensional and time has one dimension. Thus, as
shown in Figure 1.1, a distribution of the four factors in seven dimensions, that is, a set of each
of the coordinate points of light intensity, space, wavelength, and time constructs the image
information.
The indexes that indicate the level of information quality are accuracy and range,
as shown in Figure 1.2. While the accuracy of value is the resolution capability, which
means the signal-to-noise ratio (SNR), the range is the extent of the signal information
that the imaging system can pick up. Information captured with high accuracy and over
a wide range is high-quality image information. In the case of light intensity, for example,
the information quality is decided by the level of SNR and the dynamic range, which
decribes the maximum and minimum measurable light intensities that the imaging system
can capture, as shown in Figure 1.3.
(Intensity, space, wavelength, time)
Object in 3-D
Optical image in 2-D
(
i
,
r
,
λ,
t
)
Four factors
1-D,
2-D,
3-D,
1-D
Seven dimensions
Image information is based on a set of coordinate points in
seven-dimensional space of four factors.
FIGURE 1.1
Structure of optical image information.
Maximum treatable value
Range
Accuracy
(resolution)
Minimum treatable value
0
FIGURE 1.2
Quality of image information: Accuracy and range.
