CompassImg
DESCRIPTION
Computes the directional gradient of an image in a direction specified
by its I and J components. A positive I component points East (the X
direction) and a positive J component points North (the Y direction).
For comparison with the other Compass directional modules, North (0
degrees) is I=0,J=1 and East (90 degrees) is I=1,J=0. The gradient is
computed using a square kernel whose edge length is governed by the
Kernel Size parameter. The Bias parameter adds a constant amount to
the output gradient array. This directional gradient computation is
described in:
Digital Image Processing, Gonzales, R.C., Wintz, P.,
Addison Wesley, Second Edition, 1987, pp 176--179.
INPUTS
Port: Img In
Type: Lattice
Constraints: 1..3-D.
source image
WIDGETS
Port: I Weight
Type: Dial
I component of direction (East)
Port: J Weight
Type: Dial
J component of direction (North)
Port: Bias
Type: Slider
additive bias
Port: Kernel Size
Type: Slider
length of one side of kernel
OUTPUTS
Port: Img Out
Type: Lattice
Constraints: 1..3-D.
directional gradient image
PROBLEMS
SEE ALSO
CompassDirImg
CompassAngleImg
Gradient
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© The Numerical Algorithms Group Ltd,
Oxford UK. 1996