Download Gimp - 2.2 User Guide

CHAPTER 13. FILTERS
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Density Density controls the amount of dust elements that will populate the layer. A
setting that is too high here can become extremely processor-intensive, so adjust
this setting carefully.
Seed Seed is the numeric randomization base. Changing this number will result in
different dust element shapes and positions.
Length Length controls the length of the dust artifacts. A higher setting here will result
in longer curls of dust.
13.6
Adjust FG-BG / Color Range Mapping
Overview
The Adjust FG-BG filter applies your current Foreground and Background colors
to the active image based on brightness of the image. The filter determines the color
gradient of the image based on the coloring of the image, and applies a gradient based
on the Foreground, and Background colors.
The Color Range Mapping filter provides a dialog such that the Foreground and
Background colors may be chosen. Colors for the source and destination may be selected. Color Mapping
A common use for this filter is repairing the color balance of faded photos. Opening
a faded photo, and selecting a Foreground, and Background colors that are suitable for
the photo, and then running the Adjust FG-BG, can produce desirable results.
13.7
Alien Map 2
Overview
The Alien Map 2 filter is a color manipulation filter based on the Alien Map filter. Alien
Map 2 is much more advanced in that it can perform calculations based not only on the
RGB properties of the active image or layer, but also the HSL properties of the active
image. More control of the math involved is possible, allowing the user to adjust the
Frequency and the Phaseshift values which can yield more profound transformations.
Alien Map 2 Options
Alien Map 2 Settings
Mode There are two available options for Mode.
• RGB Color Model: This option will allow Alien Map 2 to work with Red,
Green, and Blue colors only.
• HSL Color Model: This option will allow Alien Map 2 to work within the Hue,
Saturation, and Luminance of the image, layer, or selection.
Modify Red/Hue Channel This checkbox allows modifications to be made to the Red
or Hue of the active selection or layer.
Modify Green/Saturation Channel This checkbox allows modifications to be made to
the Green or Saturation of the active selection or layer.