Patent ID: 6967653

Claim:
An computer-implemented apparatus for semi-automatic classification of volume data, comprising: a histogram module that generates two-dimensional histograms of the data; a gradient estimator that computes gradients for the data; said gradients being computed according to a multiquadric: M ⁡ ( p ) = ∑ i = 1 N ⁢ ⁢ d i ⁢  p - p i  2 + R 2 + a + bx + cy + dz , p = ( x , y , z ) ; where M ⁡ ( p i ) = f i ∑ i = 1 N ⁢ ⁢ d i = 0 ∑ i = 1 N ⁢ ⁢ d i ⁢ x i = 0 ∑ i = 1 N ⁢ ⁢ d i ⁢ y i = 0 ∑ i = 1 N ⁢ ⁢ d i ⁢ z i = 0 , wherein the volume of data comprises a plurality of regions R j , and wherein a multiquadric M j may be computed for each of the plurality of regions R j ; a module that computes average and median edge values based on the computed gradients; and a threshold module that applies a threshold setting to the average and median edge values to enable rendering of the volume data in a human interpretable format on a display device.