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isthmuses while close widens the isthmuses. Close and proper-close fill 
small holes in the particle. Auto-median removes isthmuses and fills holes. 
Refer to Chapter 9, Binary Morphology, of the IMAQ Vision Concepts 
Manual for more information about these methods.

After you create a binary image and improve it, you can make particle 
measurements. IMAQ Vision can return the measurements in uncalibrated 
pixels or calibrated real-world units. With these measurements you can 
determine the location of particles and their shape features. Use the 
following functions to perform particle measurements:

•

imaqCountParticles()

—This function returns the number of 

particles in an image and calculates various measurements for each 
particle.

•

imaqMeasureParticle()

—This function uses the calculations 

from 

imaqCountParticles()

 to return specific measurements of 

a particle.

Table 4-1 lists all of the measurements that 

imaqMeasureParticle()

 

returns.

Table 4-1.  Particle Measurements

IMAQ_MT_AREA

Area of the particle

IMAQ_MT_AREA_BY_IMAGE_AREA

Percentage of the particle area 
covering the image area

IMAQ_MT_AREA_BY_PARTICLE_AND_HOLES_AREA

Percentage of the particle area in 
relation to the area of its particle and 
holes

IMAQ_MT_AVERAGE_HORIZ_SEGMENT_LENGTH

Average length of a horizontal 
segment in the particle

IMAQ_MT_AVERAGE_VERT_SEGMENT_LENGTH

Average length of a vertical segment 
in the particle

IMAQ_MT_BOUNDING_RECT_BOTTOM

Y-coordinate of the lowest particle 
point

IMAQ_MT_BOUNDING_RECT_TOP

Y-coordinate of the highest particle 
point