gen_measure_rectangle2

Herror ::gen_measure_rectangle2 ( const HTuple &Row, const HTuple &Column, const HTuple &Phi, const HTuple &Length1, const HTuple &Length2, const HTuple &Width, const HTuple &Height, const HTuple &Interpolation, long *MeasureHandle )

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.

With ::gen_measure_rectangle2, all computations which can be used for multiple measurements are removed from the actual measurement. To effect this, an optimized data structure, a so-called measure object, is constructed and returned in MeasureHandle. In order to perform the measurement at the optimum speed, the size of the images for which subsequent measurements will be made must already be specified in ::gen_measure_rectangle2 with the parameters Width and Height. This technique increases the speed of the actual measurement significantly.

Parameters

`Row` (input_control)	rectangle2.center.y `->` HTuple.double / long
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 `->` HTuple.double / long
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 `->` HTuple.double / long
Angle of longitudinal axis 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 `->` HTuple.double / long
Half width.
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 `->` HTuple.double / long
Half height.
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 `->` HTuple.long
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 `->` HTuple.long
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 `->` HTuple.char *
Type of interpolation to be used.
Default value: 'nearest_neighbor'
List of values: 'nearest_neighbor', 'bilinear', 'bicubic'

`MeasureHandle` (output_control)	measure_id `->` long *
Measure object handle.

Result

If the parameter values are correct the operator ::gen_measure_rectangle2 returns the value H_MSG_TRUE. Otherwise an exception handling is raised.

Possible Predecessors

::draw_rectangle2

Possible Successors

::measure_pos, ::measure_pairs

Alternatives

::edges_sub_pix

Module

Sub-pixel operators