EC CL - Extract Connected Clusters

PURPOSE

Segments a volume that contains two or more unconnected objects of the same intensity. The resulting volume can be used for masking or with other 'EC' operations.

'EC CL' works by reading a SPIDER 3D image file and a threshold level. It locates connected clusters of voxels that are above the threshold. Each cluster is given a number. A new 3D image file is created that contains a cluster number for each object voxel or zero for background voxels. Connectivity is six fold here (left, right , up, down, top & bottem).

SEE ALSO

EC SELECT	[Extract Connected Clusters - Selection]
EC CLOSE	[Extract Connected Clusters - merge close clusters]
EC FILTER	[Extract Connected Clusters - Filter]
EC STAT	[Extract Connected Clusters - Statistics]

USAGE

.OPERATION: EC CL

.INPUT FILE: VOL001
[File containing SPIDER 3D image (volume) to be segmented.]

.ENTER SLICE NUMBERS: 1-64
[Range of image slices the user wants to search.]

.THRESHOLD LEVEL: 1.3
[Finds connected clusters that have a value greater than this threshold.]

.CLUSTER OUTPUT FILE: VVV001
[Output cluster file name.]

NOTES

1. If the following output is observed, no clusters were found for the given threshold value. Try a larger threshold value.
   

    
                 Original:     0 clusters mapped to:     0              
    
   

2. Usually you will want to follow this operation with the 'EC STAT' operation.

SUBROUTINES

CONINT, FILSLI, CCONECT, GOTBRANCH, EMPSLI, SHOSLI, SHOSLI2, MAKTAB, MAPIM

CALLER

UTIL6