Fig 5. Creation of transfer functions using ilr coordinates.

(A) The user starts with the 2D histogram representation of ilr coordinates 1 and 2 (left side) and concurrent visualization of the original brain data (right side). The user can then interact with and select data as described in Fig 3. (B) The interaction with the 2D histogram results in data-driven shapes, here shaded in pink, green and blue (left side). Voxels selected by those areas are highlighted in corresponding colors against the backdrop of the original brain data (right side). The visualization reveals that the area of the 2D histogram shaded in blue selects brain voxels, while the areas shaded in green and pink select CSF* and blood vessel voxels**/dura mater***, respectively. The arrow with exclamation mark (!) indicates an area affected by T2*w image artifacts.