Applying Visual Effects to Clips and Shapes
In addition to letting you interactively clip image data, regions of interest, multi-ROIs, and meshes, additional visual effects can also be applied to the clipped region of selected objects, such as look-up table functions, edge contrast, and window leveling. Visual effects, which are available in the Visual effects box shown below, can also be applied to shapes such as boxes, capsules, cylinders, and spheres (see Shapes).
Visual effects for clips and shapes
For a selected effect, the Effects box displays the properties based on the nature of the effect and includes controls, such as sliders, menus, and color swatches, that you can use to change its properties. You should note that multiple effects can be applied simultaneously (see Working with Multiple Effects).
Visual effects can be applied either to the inside or outside of the clipped region or shape. Check the Outside option to apply the effect to the data of selected visuals that is exterior to the region. Leave the Outside option unchecked to apply the effect to the data of selected visuals inside the clipped region or shape.
The following effects can be applied to the currently checked object or objects.
| Example | Description | |
|---|---|---|
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Clip |
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If selected, the data of selected visual(s) that corresponds to the inside or outside of the Clip box or shape will be clipped. |
| Edge Contrast* |
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If selected, the intensity values of selected image data that corresponds to the inside or outside of the clipped region or shape will be modulated with the values of their gradient modulus to produce an image in which edges are emphasized and other features are semi-transparent. The degree of contrast can be adjusted with the Contrast slider, as shown below.
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| Fill** |
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If selected, the voxels that correspond to the inside or outside of the clipped region or shape will be filled with a solid color. To select a fill color, click the color swatch and then choose a color in the Color dialog.
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Lookup Tables* |
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If selected, a lookup table function (LUT) or an absolute LUT will be applied to selected image data that corresponds to the inside or outside of the clipped region or shape. LUTs determine how regions within specific arrays of intensity are highlighted and how color is applied (see Using the LUT Editor). Look-up tables can be selected in the drop-down menu, as shown below.
Absolute LUT… Color mapping will be applied independently of window leveling. This means that the colors mapped to specific values will be retained whenever leveling values are changed. For regular LUT functions, colors will be remapped to the range of values defined by the window width. Cyclical LUT… Specific values will be mapped to a color map of k discrete colors, values 1 through k are be mapped to those colors. Values k+1 through 2*k are mapped to the same colors, while values 2*k+1 through 3*k are mapped to those same colors and so on. |
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Window Leveling* |
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If selected, independent window level values can be applied to the data of selected visual(s) that corresponds to the inside or outside of the Clip box or shape. The width of the window, as well as its center value, can be selected with the Width and Center sliders, as shown below.
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* Applicable to selected image data and image data corresponding to selected regions of interest and multi-ROIs.
** For image data, all voxels within the bounding box will be considered. For regions of interest and multi-ROIs, only labeled voxels will be considered. For meshes, only voxels that correspond to the surface of the mesh will be considered.
Working with Multiple Effects
In some cases, you may find it advantageous to apply multiple effects to a visual or visuals. For example, edge contrast and a look-up table.
Multiple effects of edge contrast and a LUT
You should note that when rendering a visual, Dragonfly will apply the selected effects in the order in which they appear in the Effects panel. Reordering effects will have an impact on the final look of the visual by either subtly or dramatically changing its appearance. If required, you can reorder selected effects with the Up and Down buttons on the right side of the panel, as shown below.
Reordering effects
