If you change settings for an Image Set, the changes may be applied to either the active image or to the entire set, depending on the state of the (Process) button. For RGB images, the adjustments of the transfer function are handled by the Palette Properties dialog. The current transfer function parameters are shown below the histogram graph. In top-down order are the Sample Region, Range, and Stretch settings. These properties are described in detail in Transfer Functions. See Choosing Transfer Function Settings for tips on setting the controls.

Transfer Function properties can be specified using controls on the pane, by using equivalent properties in the View > Transfer Function submenus, or by using menus commands opened from the drop menu on the button on the Image Tools Toolbar.

Sample Region

The Sample Region selects the sampling region where the image intensity is measured for calculating the transfer function. The options are as follows:

Entire Image: Samples the entire image.

Cursor: Samples intensity inside the Image Cursor.

Cursor Live: Samples intensity inside the Image Cursor and updates as the cursor moves. This slows cursor movement.

Range

The Range specifies how the intensity limits are calculated from the sample region. One of the options allows you to force the minimum and maximum to specific values.

Stretch

The Stretch provides options for extending the transfer function to higher or lower intensity. The options are as follows:

Linear: Uses no Bias with equal Grayscale spacing between the transfer function's limiting values.

Log: Extends the transfer function to greater contrast at lower intensity values.

Gamma: Extends the transfer function to higher or lower intensity based on the gamma setting. A gamma less than 1 biases toward higher contrast in lower intensity, and vice versa.

Gamma Slider

Sets the gamma value when Gamma stretch is selected.

Min Z

Specifies the minimum Z (intensity) value. This is active only when the Specify Z Stretch is selected.

Max Z

Specifies the maximum Z (intensity) value. This is active only when the Specify Z Stretch is selected.

Min %

Specifies the minimum percentile intensity. This is active only when the Percentile Stretch is selected.

Max %

Specifies the maximum percentile intensity. This is active only when the Percentile Stretch is selected.

Contrast

Specifies the contrast value when the Autoscale Stretch is selected.

Save

Opens the Default Transfer Function Properties dialog for saving the current settings as a profile for future use. See below.

Note

The Transfer Function Pane does not apply to RGB images. For RGB images, use the Palette Pane or Palette Properties dialog instead.