Note: this help page in general uses the spelling "color".
Depending on the branding of your SNAP application, elsewhere in
your application the spelling may be "colour"
Overview
This page enables the user to modify the default settings for
the Color Manipulation tool. Note: any changes made to the
preferences will not be automatically updated until the application
is either restarted or a new view window is opened.
To open the color manipulation preferences window select
/Tools/Options/Color Manipulation from the main menu (Note: this
may be located instead in File/Preferences on the Mac).
Default Palettes
These will be palettes to use with the associated field
name.
- GRAY SCALE: The color palette to use if the field "GRAY
SCALE" is selected.
- STANDARD: The color palette to use if the field
"STANDARD" is selected. This by default is a rainbow spectrum type
of palette.
- UNIVERSAL: The color palette to use if the field
"UNIVERSAL" is selected. The universal palette field is intended
for color-blind compliant palettes.
- ANOMALIES: The color palette to use if the field
"ANOMALIES" is selected. This is intended but not limited to an
anomaly type of palette.
Standard Options
This is the default behavior when opening a new band or clicking
on the reset button and a color scheme is not being applied.
- Use Standard Options as Default - Use following
"Standard Options" as default when opening a band, otherwise use
settings from the file reader.
- Palette: - The palette to use for the scheme.
- GRAY SCALE: Uses the scheme as defined in the
preferences field "GRAY SCALE".
- STANDARD: Uses the scheme as defined in the preferences
field "STANDARD".
- UNIVERSAL: Uses the scheme as defined in the preferences
field "UNIVERSAL".
- ANOMALIES: Uses the scheme as defined in the preferences
field "ANOMALIES".
- Range: - The range to use.
- From Data: Uses the range from the statistics of the
data.
- From Palette File : Uses the range as defined in the
palette file.
- Log Scaling: - The log scaling to use for the scheme.
- TRUE : Log scaling will be set to true.
- FALSE : Log scaling will be set to false.
- From Palette File : Uses the range as defined in the
palette file. (Note cpt format files do not contain this
field.)
Scheme Options
This is the behavior regarding applying color schemes when
opening a new band or clicking on the reset button. If the "Apply
Color Schemes Automatically" button is clicked and the bandname
matches a regular expression scheme lookup (defined in the
configuration file
~/.snap/auxdata/color_schemes/color_palette_schemes_lookup.xml)
then a color scheme is applied (palette, range, log scaling).
- Apply Color Schemes Automatically: Automatically apply
the color schemes when a band is opened or reset button is
clicked.
- Palette: - The palette to use for the scheme.
- From Scheme STANDARD: Uses the scheme from the
configuration file defined by the parameter
"STANDARD_FILENAME".
- From Scheme UNIVERSAL: Uses the scheme from the
configuration file defined by the parameter "UNIVERSAL_FILENAME".
The universal palette field is intended for color-blind compliant
palettes.
- GRAY SCALE: Uses the scheme as defined in the
preferences field "GRAY SCALE".
- STANDARD: Uses the scheme as defined in the preferences
field "STANDARD".
- UNIVERSAL: Uses the scheme as defined in the preferences
field "UNIVERSAL".
- ANOMALIES: Uses the scheme as defined in the preferences
field "ANOMALIES".
- Range: - The range to use for the scheme.
- From Scheme: Uses the scheme from the configuration file
defined by the parameters "MIN" and "MAX".
- From Data: Uses the range from the statistics of the
data.
- From Palette File : Uses the range as defined in the
palette file.
- Log Scaling: - The log scaling to use for the scheme.
- From Scheme: Uses the log scaling from the configuration
file defined by the parameter "LOG_SCALE".
- From Palette File : Uses the range as defined in the
palette file. (Note cpt format files do not contain this
field.)
- TRUE : Log scaling will be set to true.
- FALSE : Log scaling will be set to false.
Percentile Range
Histogram-based range settings which get applied to palette.
- Percentile Range Default: Default palette range based on
percentage of pixels in a band. This is used when scheme is
disabled or when "From Data" is the specified behavior. This is
also used with the "From Data" button.
- 1σ (68.27%) Button: Enables this button in the
"sliders editor". This function adjusts the palette range to cover
1σ (68.27%) of all pixels in the band.

- 2σ (95.45%) Button: Enables this button in the
"sliders editor". This function adjusts the palette range to cover
2σ (95.45%) of all pixels in the band.

- 3σ (99.73%) Button: Enables this button in the
"sliders editor". This function adjusts the palette range to cover
3σ (99.73%) of all pixels in the band.

- 95% Button: Enables this button in the "sliders editor".
This function adjusts the palette range to cover 95% of all pixels
in the band. This is retained as a legacy function.

- 100% Button: Enables this button in the "sliders
editor". This function adjusts the palette range to cover 100% of
all pixels in the band.

Scheme Selector Options
These are options to how and what is displayed in the color
scheme selector in the "Basic editor". The pre-defined color
schemes which appear in this selector are configured in the file:
~/.snap/auxdata/color_schemes/color_palette_schemes.xml.
- Verbose: - This is the longer verbose name of the color
scheme as defined by the parameter "VERBOSE_NAME" in the
configuration file.
- Sort: - This schemes are sorted alphabetically. If sort
is false then the schemes appear in the same order as they are
defined in the configuration file.
- Categorize: - This categorizes the display of the
schemes in the selection into "Primary Schemes" and "Additional
Schemes" as determined by the boolean parameter "PRIMARY" in the
configuration file.
- Show Disabled: - Schemes could be disabled for various
reasons such as the color palette of the scheme does not exist. If
this field is checked then those schemes will be displayed in grey.
If you click on the scheme then a dialog will indicate why the
scheme is disabled.
Sliders Editor Options
- Histogram Zoom: - The histogram will by default be
zoomed in to span the min/max range of the color palette
(sliders).
- Show Information: - The statistical information overlay
within the histogram plot window will be displayed by default.
- Vertical Zoom Buttons: Enables the vertical zoom buttons
in the "sliders editor".

- Information Button: Enables this button in the "sliders
editor". This function enable display of statistical information
overlaid in the histogram plot window..

RGB Options
- Range Button (Min): - The value at which the preset
range button sets the first (minimum) point of the color palette.

- Range Button (Max): - The value at which the preset
range button sets the last (maximum) point of the color palette.

Restore
Restores all parameters within the Color Manipulation
Preferences to the original default values.