The Draw Objects tool is useful to identify complex 3D structures that can’t easily be segmented using threshold-based techniques. This tool can be used to define completely new objects. The objects drawing workflow starts by defining the outline of objects on a 2D plane. The drawing procedure is continued over all the planes on which the object is extending, scrolling through the stack as needed, until the object is completely outlined. Existing objects can be also be modified adjusting the outline shape.

Defining the outline of objects on a 2D plane:

  1. By default, the brush tool is activated.
  1. Drag and drop the brush tool on the image to define the outline of the object in the current plane.
  2. To remove unnecessary parts of the objects, use the right mouse button to erase portion of the outline with the brush, or select the erase tool from the toolbar.
  3. As you navigate up or down through the stack a shadow of the object outline will appear shaded white.
  4. Use the brush or erase tool on this shadow to confirm the presence of the object in the current plane.
  5. The outline will turn blue
  6. Correct the outline as required. NOTE: Outlines of the same object defined over non-contiguous planes will automatically be interpolated through interstitial planes and appear as blue dashed regions. These can be corrected using the brush or erase tool as needed.
  7. Proceed to add or remove as much of the outline as needed through the whole depth of the object, until the object outline is complete.
  8. Click the Finish button to validate your results, or the Cancel button to discard changes.

As mentioned previously, rather than to define a new object, the Draw Objects tool can also be used to correct existing objects. In that case you should start by using the Select Object button to first activate an object for editing and then use the brush and erase tools as described above. Users can also use an ellipse of polygon to define the outline on the active plane. In either case the brush or erase tools can still be used to further amend the outline if needed.