Prepare the extraction of straight edges perpendicular to a rectangle.
gen_measure_rectangle2 prepares the extraction of straight edges which lie perpendicular to the major axis of a rectangle. The center of the rectangle is passed in the parameters Row and Column, the direction of the major axis of the rectangle in Phi, and the length of the two axes, i.e., half the diameter of the rectangle, in Length1 and Length2.
The edge extraction algorithm is described in the documentation of the operator measure_pos. As discussed there, different types of interpolation can be used for the calculation of the one-dimensional gray value profile. For Interpolation = 'nearest_neighbor', the gray values in the measurement are obtained from the gray values of the closest pixel, i.e., by constant interpolation. For Interpolation = 'bilinear', bilinear interpolation is used, while for Interpolation = 'bicubic', bicubic interpolation is used.
To perform the actual measurement at optimal speed, all computations that can be used for multiple measurements are already performed in the operator gen_measure_rectangle2. For this, an optimized data structure, a so-called measure object, is constructed and returned in MeasureHandle. The size of the images in which measurements will be performed must be specified in the parameters Width and Height.
The system parameter 'int_zooming' (see set_system) affects the accuracy and speed of the calculations used to construct the measure object. If 'int_zooming' is set to 'true', the internal calculations are performed using fixed point arithmetic, leading to much shorter execution times. However, the geometric accuracy is slightly lower in this mode. If 'int_zooming' is set to 'false', the internal calculations are performed using floating point arithmetic, leading to the maximum geometric accuracy, but also to significantly increased execution times.
Note that when using bilinear or bicubic interpolation, not only the measurement rectangle but additionally the margin around the rectangle must fit into the image. The width of the margin (in all four directions) must be at least one pixel for bilinear interpolation and two pixels for bicubic interpolation. For projection lines that do not fulfill this condition, no gray value is computed. Thus, no edge can be extracted at these positions.
|
Row (input_control) |
rectangle2.center.y -> real / integer |
| Row coordinate of the center of the rectangle. | |
| Default value: 50.0 | |
| Suggested values: 10.0, 20.0, 50.0, 100.0, 200.0, 300.0, 400.0, 500.0 | |
| Typical range of values: 0.0 <= Row <= 511.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
|
Column (input_control) |
rectangle2.center.x -> real / integer |
| Column coordinate of the center of the rectangle. | |
| Default value: 100.0 | |
| Suggested values: 10.0, 20.0, 50.0, 100.0, 200.0, 300.0, 400.0, 500.0 | |
| Typical range of values: 0.0 <= Column <= 511.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
|
Phi (input_control) |
rectangle2.angle.rad -> real / integer |
| Angle of longitudinal axis of the rectangle to horizontal (radians). | |
| Default value: 0.0 | |
| Suggested values: -1.178097, -0.785398, -0.392699, 0.0, 0.392699, 0.785398, 1.178097 | |
| Typical range of values: -1.178097 <= Phi <= 1.178097 (lin) | |
| Minimum increment: 0.001 | |
|
Recommended increment: 0.1 | |
| Restriction: (- pi < Phi) && (Phi <= pi) | |
|
Length1 (input_control) |
rectangle2.hwidth -> real / integer |
| Half width of the rectangle. | |
| Default value: 200.0 | |
| Suggested values: 3.0, 5.0, 10.0, 15.0, 20.0, 50.0, 100.0, 200.0, 300.0, 500.0 | |
| Typical range of values: 0.0 <= Length1 <= 511.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
|
Length2 (input_control) |
rectangle2.hheight -> real / integer |
| Half height of the rectangle. | |
| Default value: 100.0 | |
| Suggested values: 1.0, 2.0, 3.0, 5.0, 10.0, 15.0, 20.0, 50.0, 100.0, 200.0 | |
| Typical range of values: 0.0 <= Length2 <= 511.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
| Restriction: Length2 <= Length1 | |
|
Width (input_control) |
extent.x -> integer |
| Width of the image to be processed subsequently. | |
| Default value: 512 | |
| Suggested values: 128, 160, 192, 256, 320, 384, 512, 640, 768 | |
| Typical range of values: 0 <= Width <= 1024 (lin) | |
| Minimum increment: 1 | |
|
Recommended increment: 16 | |
|
Height (input_control) |
extent.y -> integer |
| Height of the image to be processed subsequently. | |
| Default value: 512 | |
| Suggested values: 120, 128, 144, 240, 256, 288, 480, 512, 576 | |
| Typical range of values: 0 <= Height <= 1024 (lin) | |
| Minimum increment: 1 | |
|
Recommended increment: 16 | |
|
Interpolation (input_control) |
string -> string |
| Type of interpolation to be used. | |
| Default value: 'nearest_neighbor' | |
| List of values: 'nearest_neighbor', 'bilinear', 'bicubic' | |
|
MeasureHandle (output_control) |
measure_id -> integer |
| Measure object handle. | |
If the parameter values are correct the operator gen_measure_rectangle2 returns the value 2 (H_MSG_TRUE). Otherwise an exception handling is raised.
gen_measure_rectangle2 is reentrant and processed without parallelization.
measure_pos, measure_pairs, fuzzy_measure_pos, fuzzy_measure_pairs, fuzzy_measure_pairing, measure_thresh
1D Metrology
