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.

KNOWN PROBLEMS

SEE ALSO

CompassDirImg, CompassAngleImg, Gradient.
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© The Numerical Algorithms Group Ltd, Oxford UK. 2000