VBNDDIST

VisionX V4

NAME

vbnddist − compare a boundary with a binary image for partial ground truth evaluation

SYNOPSIS

vbnddist if=<image> bf=<boundary file> [xyres=<value>] [zres=<value>] [res=<x,y,z>] [-2d] [-sh] [-wi] [-v]

DESCRIPTION

vbnddist compares a VisionX boundary file with a binary image in byte format (such as the images typically generated by an automated segmentation algorithm). For each point in the boundary file, the program computes the Euclidean distance to the closest surface point in the binary image. Surface points in the binary file are determined by examining the neighbors of each non-zero pixel in the binary image; if any neighbors are background, then the pixel is on the surface.

To determine which points are on the surface of the region, the program checks the 6-connected neighbors. This effectively means the region is 27-connected.

In computing Euclidean distance, the resolution given on the command line or read from the file history is used. The res= parameter has the highest priority, followed by the xyres= and zres= parameters, then the DICOM resolution, and finally a default of 1.0.

Note that boundary files created using the java applet on the web system or vdview may need correction with vxftoz if the boundaries were created on a clipped image.

The program reports several counts and derived statistics. These are explained below.

	ptdistlst		List of distances for each boundary point of bf
	avgdist		Average distance for the boundary points of bf
	rmsdist		Root-mean-sqare distance for the boundary points of bf

OPTIONS

if=<image file>

specifies a VisionX byte image file, with non-zero pixels considered part of the region. If this parameter is not specified, it will be read from standard input.

bf=<boundary file>

specifies a VisionX boundary file, as generated by the marking tools in vdview or the Java viewer. If this parameter is blank or omitted, it will be read from standard input.

xyres=<value>

if this value is specified, the resolution will be used when computing distance.

zres=<value>

if this value is specified, the resolution will be used when computing distance.

res=<x,y,z>

if this value is specified, the resolution will be used when computing the distance. This is a comma-separated list of 3 values; for example, 0.5,0.5,1.0 would result in an x-resolution of 0.5, a y-resolution of 0.5, and a z-resolution of 1.0.

	-2d		determines surface points using 2D criteria. Only points in the same slice as the boundary point are considered when searching for the closest point.
	-wi		output statistics in format suitable for TCL parsing.
	-sh		output statistics in format suitable for shell parsing (default).
	-v		verbose output.

SEE ALSO

vbndcmp(1), vxftoz(1)

AUTHOR

A. C. Jirapatnakul and A. P. Reeves