Brain Imaging & Analysis Center

usage: -expr gradient – create a local intensity gradient map

The GRADIENT function analyzes the local intensity gradient around each voxel and generates a gradient map in which each map value is a composite index of the intensity gradient along the X, Y, and Z axes.

Each map value is a 16-bit integer with 3 5-bit fields, in the binary form: ZZZZZYYYYYXXXXX
Within each field, you should subtract 16 from the 5 bit value (0-31) to get the gradient value (-15 - +15).

The gradient value indicates the average slope of the intensity gradient along that axis.

See Also:
Peak

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