Manual

June 2004 Isis® Sonar User's Manual, Volume 2 86
Equalize
(button)
Equalize manipulates the dynamic range of the colors in the
image. The choices in the drop-down box are:
•
None: No equalization is applied to the image.
•
Best: Enhance attempts to do a “best fit” of the range of
colors in the image based on shadows and highlights.
The bottom 3% of the range is defined as a shadow
point, while the top 3% of the range is defined as a
highlight; then all remaining values in between
shadows and highlights are evenly distributed
throughout the range.
•
Linear: All values are distributed equally throughout the
range.
•
Bell: All values are distributed evenly around the center
of the scale. This produces a high contrast image, but
one with a more limited dynamic range than an image
enhanced by Linear equalization.
•
Logarithmic: Favors (skews) the values toward the low
end of the scale, effectively making the image darker
with greater contrast. The dynamic range of the colors
is compressed (squashed).
•
Exponential: Favors (skews) the values toward the high
end of the scale, effectively making the image lighter
with less contrast. As with
Logarithmic, the dynamic
range of the colors is compressed.
Invert Colors
(check box)
If checked, all colors are reversed: White becomes black, black
becomes white, etc. The primary colors red, green and blue can
be inverted independently of one another by putting a check
mark in any of the
R, G, or B box or boxes.
Min/Max
(slider bar)
See page 83 for a discussion of min/max effects.
Brightness
(slider bar)
Sliding the bar to the right brightens the image; sliding it to the
left darkens it. When the bar is at the midpoint (+0%), the image
has neutral brightness (no change in brightness). Range is
-100% (dimmest) to +100% (brightest).
Contrast
(slider bar)
Sliding the bar to the right increases the image’s contrast; sliding
it to the left decreases it. When the bar is at the midpoint (+0%),
the image has neutral contrast (no change in contrast). Range is
-100% (least contrast) to +100% (most contrast).
Appendix E: Using the Target Utility