DS9 Reference Manual
Table of Contents

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.

100%

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

99.5% to 50%

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

This is mix of 100% and ZScale. Set the lower limits base on the IRAF ZScale algorithm and the upper limit to the max data value.

Scale Parameters

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

Scale

Select color distribution scale

Limits

Set the upper and lower limits via algorthim

Scope

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

Parameters

  • ZSCALE PARAMETERS -- Select the parameters for the IRAF ZScale algorithm.
  • Graph

    Display the Pixel Histogram Distribution graph with either a linear or log scale.