Volume Freehand Cropping

Algorithm to interactively remove/cut parts of a volume using a freeform selection directly in the views.

Input

A single 3D volume.

Output

A new 3D volume with the freehand cropping applied or nothing if Create new image or Apply as mask is disabled.

Description

The Volume Freehand Cropping algorithm enables you to interactively remove parts from a 3D volume. Similar to image editing software you can draw freehand selections in any of the views showing the input data and thereby define which voxels are to be removed. During editing, the views will show a live preview: all voxels that are going to be removed are tinted in red. Once you click on Apply the previewed changes are applied and the final result is computed.

../../_images/VolumeFreehandCropping.png

You can define the removed region interactively in multiple steps by drawing a freehand region in any of the views showing the input data. This will accumulate mask overlay indicating which pixels should be removed (tinted in red) and which pixels should be kept alive. Depending on the chosen Interaction mode the drawing of the freehand region has different effects on the masked region:

  • Draw: all voxels that are inside the region when projected onto the view plane will be added to the masked region.
  • Intersect: all voxels that are inside the region when projected onto the view plane and are already part of the mask will remain part of the mask. All other voxels will be removed from the mask.
  • Erase: all voxels that are inside the region when projected onto the view plane will be removed from the mask.
  • Invert: invert the mask image swapping regions that should be removed with regions that should be kept alive.
  • Clear: clear the mask so that no pixels are considered as removed anymore.

You can further configure the following options:

  • Check Create new image in order to keep the input image unchanged and create a new image as output with the result. The output image will have all masked pixels set to 0.
  • Check Apply as mask in order to keep the input image pixel values as they are but attach an explicit mask with the previsouly defined regions. See also the Apply Edit Algorithm.
  • Check Fit volume to crop in order to reduce the volume size to tightly fit the cropped region.