vbfilt − Geometric filter function for binary 3D images

vbfilt [if=<infile>] [of=<outfile>] [th=] [s=] [c=] [e=] [-e] [-n] [-d] [-v]

Vbfilt is a binary geometric filter for extracting blob like regions from other 3D image regions. Some of the other image regions may be touching the desired blob region. Input and output are 3D binary images. The size of the spherical kernel filter specifies the diameter of the largest "blob" sphere that is smaller than the blob of interest; i.e., the largest blob size to delete. By default the output image is set to the single largest connected remaining 3D region is selected for output.

The filtering action is a recursive filtering (a morphological opening followed by closings of a sequence of smaller spherical kernels. The object is to remove large attachments but to grow back the fine surface detail up to the diameter of the the spherical kernel. After filtering one connected component from the resulting binary image is selected for output.

The input 3D image need not have frame markers; however, the resulting filtered image will always have frame markers.

When -n flag is chosen, the component closest to the seed point is chosen instead of the component touching seed point because for non-solid nodule the seed point can be at a zero pixel location.

th=<value>

Set threshold for input: only input pixels having a value greater than or equal to <value> are considered to be foreground. The default value is 1.

s=<value>

Set the kernel size of the initial spherical kernel (diameter of sphere, default=1)

c=<x,y,z>

Select only the component that touches a point.

e=<value>

Remove components within <value> pixels of XY edges.

-e

Remove components touching XY edges.

-n

Select component closest to seed point.

-d

Remove (fill) 2D voids in components.

-v

Set the verbose mode in which vbfilt reports its progress.

A. P. Reeves