vps − print basic statistics of a VisionX file

vps [if=infile] [of=ofile] [-v3d] [-t] [-m] [-iw] [-i] [-l] [-gv] [-sh] [-w ]

Vps prints a global summary of some basic statistics and, with the -l option, some basic statistics for each image found in the file. Without any option the statistics are printed, after a heading describing the size of the images, in three columns consisting of:

- the statistical value computed on all the image pixels
- the statistical value, in parenthesis, computed on all the pixels not equal to the mask value (see option m=), and
- a brief description of the the statistical value.

Color index images are not supported.

-v3d

print some basic information about all 3-D vectors in a file instead of all images.

-t

print the number of each VisionX element type in the file (file types are not counted).

-m

print the maximum and minimum pixel values computed over all images (also print the base (bf) and times factor (tf) to scale the images from 0 to 255). This is used by vifx(1).

-i

print the image dimension information in shell format

-iw

print the image dimension information in wish (TCL) format

m=

set the mask value for image statistics; results in parenthesis or ending in ’b’ will be computed on all the image pixels with a value different from the specified mask-out value

-sh

print image statistics in shell format

-w

print image statistics in wish (TCL) format

The -i, -iw and -sh, -w options return their results as sets of variables suitable for evaluation by the respective intepreters.

The image statistics variables are

pfr

(frames in file)

pim

(images in file)

psx

(bounding box width)

psy

(bounding box height)

pox

(boundig box x origin)

poy

(boundig box y origin)

pelt

(elements in file, for vectors)

The following variables report the results for set a - all the pixels in the image, and set b - all the pixels whose value is different from the mask option m= value (default zero).

pnpa

(number of pixels)

pnpb

(number of non-masked-out pixels)

pmaxa, pmaxb

(max value)

pmina, pminb

(min value)

prana, pranb

(range value)

pmeana, pmeanb

(mean value)

pvara, pvarb

(variance)

psda, psdb

(standard deviation)

pska, pskb

(skewness)

pkua, pkub

(kurtosis)

The image information variables (options -i or -iw) are

fm

image format: u (unsigned byte), c (signed byte), s (short int), i (integer - 32-bit), f (float), d (double), b (bit), and x (index)

other formats: a (annotation), v (vector)

xl, xh, yl, yh, zl, zh

bounding box values (i.e. the next greater integer for the upper bounds)

f

frames

ch

channels

xs, ys, zs

image size in the x, y and z directions respectively

runit

unit for image resolution (px = pixels, mm = millimeters)

xres, yres, zres

image resolution

nt

number of tiles for a montage in a 512x512 view (comma separated values for x and y, respectively)

mf, mfb

scaling factors for a montage in a 512x512 view

A. P. Reeves, A. M. Biancardi