Specifications

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Chapter 9 Vision Manager
Note
What is the brightness integral?
What is the area?
What is the center of gravity?
What is the principal axis angle?
The brightness integral is the sum of the
brightness values over all camera image
pixels within the specified range in the
window.
The area is a count of pixels within the specified range in the win-
dow having the specified color after digitization: black (0) or white
(1). The DENSO µVision board implementation combines on-the-
fly digitization and counting, making it unnecessary for programs
to first digitize and also leaving the image unaltered on the
screen.
Camera images portray their subjects as flat, so here center of
gravity means in the plane. The DENSO µVision board deter-
mines the center of gravity by digitizing the pixels within the spec-
ified range in the window and then counting either black (0) or
white (1) ones. This center of gravity has both x- and y-coordi-
nates.
Camera images portray their subjects as flat, but a subject can
have its major axis (length) rotated relative to the viewing plane.
The minor axis (width) is perpendicular to this axis. The DENSO
µVision board defines the angle (θ) from the plane's x-axis to the
subject's major axis as the principal axis angle. The DENSO µVi-
sion board determines this angle by digitizing the pixels within the
specified range in the window and then counting either black (0)
or white (1) ones.
Window
Brightness integral = 100 x 13 + 20 x 12 = 1540
Window
1 (white) area = 13
0 (black) area = 12
Window
Center of gravity Subject
Window Subject
Major axis
Minor axis