Specify a normalized fuzzy member function for edge pairs.
set_fuzzy_measure_norm_pair specifies a normalized fuzzy member function passed in Function. The specified fuzzy functions enables fuzzy_measure_pos, fuzzy_measure_pairs and fuzzy_measure_pairing to evaluate and select the detected candidates of edges and edge pairs. For this purpose, weighting characteristics for different edge features can be defined by one function each. Such a specified feature is called fuzzy set. Specifying no function for a fuzzy set means not to use this feature for the final edge evaluation. Setting a second fuzzy function to a fuzzy set means to discard the first defined function and replace it by the second one. In difference to set_fuzzy_measure, the abscissa x of these member functions must be defined relative to the desired size s of the edge pairs (passed in PairSize). This enables a generalized usage of the defined functions. A previously defined normalized fuzzy member function can be discarded completely by reset_fuzzy_measure.
Functions for three different fuzzy set types selected by the SetType parameter can be defined, the sub types of a set beeing mutual exclusive:
- 'size' denotes a fuzzy set that valuates the normed
distance of two edges of a pair in pixels:
x = d/s ( x >= 0 ).
Specifying an upper bound x_max for the size by terminating the
member function with a corresponding fuzzy value of 0.0 will
speed up fuzzy_measure_pairs / fuzzy_measure_pairing because
not all possible pairs need to be considered. Additionally, this
fuzzy set can also be specified as a size difference
by 'size_diff'
x = (s-d)/s ( x <= 1 )
and a absolute normed size difference by 'size_abs_diff'
x = |s-d|/s ( 0 <= x <= 1 ).
This set is only used by fuzzy_measure_pairs/fuzzy_measure_pairing.
- The fuzzy function of 'position' evaluates the signed distance p
of each edge candidate to the reference point of the measure object,
generated by gen_measure_arc or gen_measure_rectangle2:
x = p/s.
The reference point is located at the beginning whereas
'position_center' or 'position_end' sets the reference
point to the middle or the end of the one-dimensional gray value
profile instead. If the fuzzy position evaluation depends on the
position of the object along the profile, 'position_first_edge' /
'position_last_edge' sets the referece point at the position of
the first/last extracted edge. When extracting edge pairs, the
position of a pair is referenced by the geometric mean of the
fuzzy position scores of both edges.
- Similar to 'position', 'position_pair' evaluates the
signed distance of each edge pair to the reference point of the measure
object. The position of a pair is defined by the center point
between both edges. The object's reference can be set by
'position_pair_center', 'position_pair_end' and 'position_first_pair',
'position_last_pair', respectively. Contrary to 'position', this set
is only used by fuzzy_measure_pairs/fuzzy_measure_pairing.
A normalized fuzzy member function is defined as a piecewise linear
function by
at least two pairs of values, sorted in an ascending order by their
x value. The y values of the fuzzy function represent the weight of
the corresponding feature value and must satisfy the range of 0.0
<= y <= 1.0. Outside of the function's interval, defined by the
smallest and the greatest x value, the y values of the interval
borders are continued constantly. Such Fuzzy member functions can
be generated by create_funct_1d_pairs.
If more than one set is defined, fuzzy_measure_pos / fuzzy_measure_pairs / fuzzy_measure_pairing yield the overall fuzzy weighting by the geometric mean of the weights of each set.
|
MeasureHandle (input_control) |
measure_id -> integer |
| Measure object handle. | |
|
PairSize (input_control) |
number -> real / integer |
| Favored width of edge pairs. | |
| Default value: 10.0 | |
| List of values: 4.0, 6.0, 8.0, 10.0, 15.0, 20.0, 30.0 | |
| Typical range of values: 0.0 <= PairSize | |
| Minimum increment: 0.1 | |
|
Recommended increment: 1.0 | |
|
SetType (input_control) |
string -> string |
| Selection of the fuzzy set. | |
| Default value: 'size_abs_diff' | |
| List of values: 'size', 'size_diff', 'size_abs_diff', 'position', 'position_center', 'position_end', 'position_first_edge', 'position_last_edge', 'position_pair_center', 'position_pair_end', 'position_first_pair', 'position_last_pair' | |
|
Function (input_control) |
function_1d-array -> real / integer |
| Fuzzy member function. | |
/* how to use a fuzzy function */
...
gen_measure_rectangle2 (50, 100, 0, 200, 100, 512, 512, 'nearest_neighbor',
MeasureHandle)
/* create a generalized fuzzy function to evaluate edge pairs
* (30% uncertainty). */
create_funct_1d_pairs ([0.7,1.0,1.3], [0.0,1.0,0.0], SizeFunction)
/* and set it for an expected pair size of 13.45 pixels */
set_fuzzy_measure_norm_pair (MeasureHandle, 13.45, 'size', SizeFunction)
fuzzy_measure_pairs (Image, MeasureHandle, 1, 30, 0.5, 'all', RowEdgeFirst,
ColumnEdgeFirst, AmplitudeFirst, RowEdgeSecond,
ColumnEdgeSecond, AmplitudeSecond, RowEdgeCenter,
ColumnEdgeCenter, FuzzyScore, IntraDistance,
InterDistance)
set_fuzzy_measure_norm_pair is reentrant and processed without parallelization.
gen_measure_arc, gen_measure_rectangle2, create_funct_1d_pairs
fuzzy_measure_pairs, fuzzy_measure_pairing
transform_funct_1d, set_fuzzy_measure
1D Metrology