| Operators |
symmetry — Symmetry of gray values along a row.
symmetry(Image : ImageSymmetry : MaskSize, Direction, Exponent : )
symmetry calculates the symmetry along a line. For each pixel the gray values of both sides of the line are compared: The absolute value of the differences of gray values with same distance to the pixel is computed. Each of these differences is weighted by the exponent (after division by 255) and then summed up.
Currently only horizontal search lines are implemented. Note that the parameter Direction exists for future extensions and can currently only have the value 0.0.
Input image.
Symmetry image.
Extension of search area.
Default value: 40
Suggested values: 3, 5, 7, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 100, 120, 140, 180
Typical range of values: 3 ≤ MaskSize ≤ 1000
Minimum increment: 1
Recommended increment: 2
Angle of test direction.
Default value: 0.0
Suggested values: 0.0
Typical range of values: 0.0 ≤ Direction ≤ 0.0
Exponent for weighting.
Default value: 0.5
Suggested values: 0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 0.8, 0.9, 1.0
Typical range of values: 0.05 ≤ Exponent ≤ 1.0
Minimum increment: 0.01
Recommended increment: 0.1
Restriction: 0 < Exponent && Exponent <= 1
read_image(Image,'monkey') symmetry(Image,ImageSymmetry,70,0.0,0.5) threshold(ImageSymmetry,SymmPoints,170,255)
If the parameter values are correct the operator symmetry returns the value 2 (H_MSG_TRUE) The behavior in case of empty input (no input images available) is set via the operator set_system(::'no_object_result',<Result>:). If necessary an exception is raised.
Foundation
| Operators |