4.3.4 Pseudocolor

The color list and color sliders radio buttons allow the user to choose the method of color selection.

Color List:

Select a color name from the standard list of X11 color names.

Color Sliders:

Display red, green, and blue color bars which allow the user to mix these colors to create the desired color. This is the default.

With either method of color selection, the current color is displayed in the box above the apply button.

Range:

Enter the range of image values and/or the specific image values to which the selected color is to be applied. Range values should be separated by a dash (-) and individual image values should be seaprated by either a space or a comma (,). The following conditions cause an error message to be displayed:

1. The first character in the input specification is not numeric.
2. Any alphabetic characters appear in the specification.
3. Any punctuation marks other than a dash (-) or a comma (,) are used.
4. Two consecutive punctuation marks appear in the specification.
5. Both ends of a range are not specified (i.e. "10 - " or "- 100").
6. A value less than 0 or greater than 255 is specified.

Definitions:

This text field is an informational area informing the user of the color assignments already made. Assignments made from the color list are displayed as a color name followed by the ranges and/or specific image values the color was applied to. Assignments made from the color sliders are displayed as the red, green, and blue color values followed by the ranges and/or specific image values the color was applied to.

Color List:

The color list is displayed only when the color list radio button has been selected. This is the list of standard X11 color names. The user must use the scrollbar at the right of the list to scroll through the names of available colors. To view a specific color, click the left mouse button on the color and it will be displayed in the box above the apply button.

Color Sliders:

The color sliders are displayed only when the color sliders radio button has been selected. These red, green, and blue sliders are used to mix appropriate levels of red, green, and blue to create the desired color. Slider values range from 0 (indicating no level of the particular color should be used), to 255 (indicating the full strength of the particular color should be used). For example, selecting a red value of 255 (full red), a green value of 255 (full green), and a blue value 0 (no blue) creates the color yellow. The resulting color will be displayed in the box above the apply button.

Color Box:

The color box displayed above the apply button shows the user the currently selected color.

Apply:

Apply the currently selected color to the range and/or individual image values indicated by the range text field. Validation of the range specification is done at this time. If an error is detected in the range specification, the color is not applied.

Undo:

Undo the last (and only the last) operation. The last operation may include the application of a color to the image, the restoration of the initial mapping, or the application of a linear mapping.

Restore:

Reload the mapping that was applied to the image when the pseudocolor mapping function was initiated.

Linear:

Load a linear or identity mapping.

Cancel:

Reload the mapping that was applied to the image when the pseudocolor mapping function was initiated and close the pseudocolor mapping panel.

Dismiss:

Close the pseudocolor mapping panel and save the current pseudocolor mapping.