Slicer Transfer Function for ROI - 3dct/open_iA GitHub Wiki

This page describes an interaction method in the 2D Slicers, which allows to quickly adapt the transfer function for maximum contrast in a selected region.

• Let's say you want to investigate a specific region of this image a bit further:

  The transfer function by default spans the range of intensity values of the whole dataset:

• Start by activating the "Click+Drag: Set Transfer Function for Region" mode in the context menu of any slicer.

• Then you can define a region of interest by clicking on a corner point of the intended region and keeping the left mouse button pressed; while the left mouse button is down a red rectangle indicates the region that would currently be defined:

• After releasing the mouse button, the transfer function will be adapted to the data values inside of the defined region:

  The minimum intensity value in the dataset as a whole to the minimum intensity value in the selected region is set to color black, and opacity 0%, and the maximum value in the region up to the maximum value is set to white, opacity 100%.

  This will optimize the contrast for the selected region of interest: