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Display and scaling (display)

Description: The display function within seadisp allows for default scaling on a product-by-product basis as well as user-controlled scaling per display instance. (For a description of the default scaling used, and how to control it, see Default Scaling discussion).

[Interactive mode][Command mode]


Command mode:

Usage:display, band_no=band_no, fbuf=fbuf, lutnum=lutnum, smin=smin, smax=smax, stype=stype, /GEO, /RAW

Note:  The command mode procedure load must be run before display.

Arguments/Keywords:
band_no The number of the product in the loaded bands list to display. Relative to 1. (Default=1).
fbuf The seadisp window number to load the product into. (Default is the current window).
lutnum The color table number to associate with this displayed window. (Default=1).
Scaling keywords  The scaling keywords allow you to override the scaling defaults found in the $SEADAS/config/seadas_defaults file or in your personal .seadas_defaults file located in your home directory.
 
smin The minimum value to be used for scaling.
smax The maximum value to be used for scaling.
stype 'LOG' or 'LIN'
geo Specify that smin and/or smax are represented in geophysical data values.
raw Specify that smin and/or smax are represented in raw data values.

Examples:

  1. Display the first loaded product into the current window (#1 if there is no window opened).
  2. display
  3. Display loaded product #5 into display window #2:
  4. display, fbuf=2, band_no=5
  5. Display loaded product #3 into display window #2 and override the default display scaling:
  6. display, fbuf=2, band_no=3, smin=1.0, smax=4.0, stype='LIN', /GEO

Interactive Mode:

Description:The display function is performed interactively by selecting a product in the Band List Selection Widget and then pushing the Display button. (For the default scaling used, see Default Scaling discussion).  To rescale an image once it is displayed, select the Functions->Rescale menu item in the Display Window Widget.

Rescale Widget:


 

The Rescale Widget allows the rescaling of the raw band data into the displayed image. The data will always be scaled into the available 8-bit range reserved for SeaDAS data. New data min/max values can be specified as well as linear or log scaling.

Action Items:
 
Scale Min The minimum data value for scaling in terms of either Raw band data values or Geo-Physical data values (depending on Geo/Raw toggle).
Scale Max The maximum data value for scaling in terms of either Raw band data values or Geo-Physical data values (depending on Geo/Raw toggle).
Geo/Raw A toggle to convert between Raw band data values and Geo-Physical data values using the band data information Slope, Intercept and Scale Type as shown in the Band List Information section of the Band List Widget.
Scale Type The scale type to apply when imaging the data. This is independent from the scale type used to convert between raw and geo-physical band data values.
Reset Defaults Reload the original scaling defaults.
Reset Local Min/Max Set the data min/max to be the local min/max in the band data.
Redisplay Redisplay the raw or geo-physical band data over the data range specified using the scale type specified.
Help Bring up help about Rescale Widget in HTML viewer.
Quit Delete the Rescale Widget.



Default scaling used for interactive and command modes

Default scaling values are currently determined by searching for a product match in the SeaDAS defaults file: $SEADAS/config/seadas_defaults. To define your own personal scaling defaults, copy this file to your home directory as a 'dot' file:

% cp $SEADAS/config/seadas_defaults $HOME/.seadas_defaults.

The $HOME/.seadas_defaults file will take precedence over the $SEADAS/config/seadas_defaults file. The user can define default display scalings in these files on a product-by-product basis. If the default has not been set, then the data will be scaled to the local min/max of the dataset using linear scaling.

NOTE:  The product name specified in the .seadas_defaults file must exactly match the product name as it appears when you load the file.  Currently, product names which contain blanks are not handled in the seadas_defaults file.


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Authorized by: gene carl feldman

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Updated: 15 December 2008