Triton TargetPro - Manual (Page 48)

June 2004 TargetPro™ User's Manual
Below the slider bars in this area are five buttons. They are Vignette,
Adapt. Norm, Sliding Window, Despeckle, and Equalize, explained next.
• Vignette (button): Vignette lighting compensates for large variations of
light (or lack of light) in the background of the image. When vignette is
applied, points furthest from the center of the image are darkest, and
points closest to the center are lightest.
• Adapt. Norm (button): This stands for “Adaptive Normalization.” It
modifies the image such that within any range of pixels (chosen by
Window Size) the outputs of Brightness, Contrast, and Smoothing are
transformed into the values chosen. Figure 17 shows an example of
the TVG dialog box which displays when you click Adapt. Norm.
• Sliding Window (button): This subtracts the mean pixel intensity for the
entire image.
• Despeckle (button): Removes “noise” from the image. Noise is defined
as any pixel that exceeds the median kernel value as defined by a
median kernel cell size and a sensitivity value. The median kernel cell
size can have values of 3, 5 or 7. Sensitivity is the number used to
determine how different the center pixel in the image region must be
before the pixel is replaced by the region’s median value. During
despeckling, the image is examined in [Cell Size] X [Cell Size] regions.
The value in the center pixel is compared to the median value for that
region. If the difference between the center value and the median value
exceeds the value specified on the Despeckle bar, the center pixel is
replaced with the median value. Otherwise, the center pixel keeps its
original value. Every pixel in the image is analyzed in this way. An
image can be despeckled in seven ways as indicated by the choices in
the Despeckle combination box:
Lead Tools
Lee (linear model and estimation)
Enhanced Lee
Frost
Enhanced Frost
Gamma
Kaun (multiplicative model and linear estimation
After choosing a type of despeckling to perform, click the Despeckle button
above the combination box to generate the desire despeckling.
• Equalize (button): This manipulates the dynamic range of the colors in
the image. An image can be equalized in five ways as indicated by the
choices in the Equalize combination box:
Chapter 4: Object Modification and Classification 37