Scale Menu

The Scale Menu is used to set the upper and lower limits and the distribution of colors, based on pixel values.

Linear

Set the colors distribution to Linear.

Log

Set the colors distribution to Log.

Squared

Set the colors distribution to Squared.

Square Root

Set the colors distribution to Square Root.

Histogram Equalization

Set the colors distribution based on a Histogram Equalization algorithm.

MinMax

Set the upper and lower limits to the min and max values, or 100%. The image may be scanned to determined these values, based on the Min Max Options.

99.5% to 90%

Set the upper and lower limits to based on the specified percentage. A histogram of the data is created and the limits are set to display the percentage, about the mean value.

ZScale

Set the upper and lower limits base on the IRAF ZScale algorithm. ZScale parameters may be configured via the preference menu.

ZMax

Set the lower limit base on the IRAF ZScale algorithm and the upper limit on the maximum data value. ZScale parameters may be configured via the preference menu.

Scope

For FITS Mosaics and Datacubes, scope specifies if the limits are applied global across each FITS Mosaic segment, or on a per segment basis.

MinMax

Specify how to determine the minimum and maximum values of the image. A selection of AUTO will use SAMPLE for all FITS Mosaics and SCAN for all other files.

ZScale

Set zscale parameters

use DATASEC

If the keyword DATASEC is present, and this option is enabled, data not in the bounding box specified by DATASEC will not be imaged, printed, or used in calculations of MinMax and ZScale. The excluded regions are usually bias strips on CCDs and contain no real data.

Scale Parameters

Invoke a non-modal dialog box to specify Scale Type, Scale Limits, and Scale parameters.