fmri_cleanclusters
==================

.. currentmodule:: fmri_toolbox

Description
-----------
FMRI_CLEANCLUSTERS  Removes small and sparse clusters from a thresholded map.
Applies two criteria to discard unreliable clusters from a binary brain map:
1. Cluster size: removes clusters smaller than CL_SIZE_THRES voxels.
2. Neighbour density: within surviving clusters, removes voxels with fewer
than NN_THRES neighbours (eliminates isolated or spikey voxels).

Usage
-----
.. code-block:: matlab

    newpmap = fmri_cleanclusters(pmap, CL_SIZE_THRES, NN_THRES)
    newpmap = fmri_cleanclusters(pmap, CL_SIZE_THRES, NN_THRES, CONN)

Inputs
------
- **PMAP**: Thresholded binary brain map, vectorized (228453 x 1) or volume (91 x 109 x 91).
- **CL_SIZE_THRES**: Minimum cluster size in voxels. Clusters smaller than this are removed entirely. Use fmri_csthreshold to obtain a statistically motivated value.
- **NN_THRES**: Minimum number of neighbours a voxel must have to be retained (range 0-26). Default: 0 (disabled).
- **CONN**: Connectivity criterion for spm_bwlabel cluster detection: 6  = face connectivity (most conservative) 18  = face + edge connectivity (default) 26  = face + edge + corner connectivity (most liberal) Default: 18.

Outputs
-------
- **NEWPMAP**: Cleaned binary map, same format as PMAP input.

Examples
--------
.. code-block:: matlab

    clean = fmri_cleanclusters(thresh_map, 50, 0);
    clean = fmri_cleanclusters(thresh_map, cs, 2);
    clean = fmri_cleanclusters(thresh_map, 50, 0, 6);   % strict face-only
    clean = fmri_cleanclusters(thresh_map, 50, 0, 26);  % liberal corner

See Also
--------
- fmri_csthreshold
- fmri_csdist
- fmri_regiontable
- fmri_tfce