National Instruments IMAQ Vision for Measurement Studio - Manual (Page 46)

Chapter 4 Blob Analysis
© National Instruments Corporation 4-7 IMAQ Vision for LabWindows/CVI User Manual
Convert Pixel Coordinates to Real-World Coordinates
If you need to find the location of the center of mass or the bounding
rectangle of the blobs in real-world units, use
imaqTransformPixelToRealWorld() .
IMAQ_ELLIPSE_MAJOR total length of the major axis of the ellipse having the
same area and perimeter as the particle in user-defined
units
IMAQ_ELLIPSE_MINOR total length of the minor axis of the ellipse having the
same area and perimeter as the particle in user-defined
units
IMAQ_ELLIPSE_RATIO fraction of the length of the major axis to the length of
the minor axis of the ellipse having the same area and
perimeter as the particle in user-defined units
IMAQ_RECT_LONG_SIDE length of the long side of a rectangle having the same
area and perimeter as the particle in user-defined units
IMAQ_RECT_SHORT_SIDE length of the short side of a rectangle having the same
area and perimeter as the particle in user-defined units
IMAQ_RECT_RATIO ratio of rectangle long side to rectangle short side
IMAQ_ELONGATION max intercept/mean perpendicular intercept
IMAQ_COMPACTNESS particle area/(height × width)
IMAQ_HEYWOOD particle perimeter/perimeter of circle having same area
as the particle
IMAQ_TYPE_FACTOR complex factor relating the surface area to the moment of
inertia
IMAQ_HYDRAULIC particle area/particle perimeter
IMAQ_WADDLE_DISK diameter of the disk having the same area as the particle
in user-defined units
IMAQ_DIAGONAL diagonal of an equivalent rectangle in user-defined units
Table 4-1. Particle Measurements (Continued)
Measurement Description