best_match_rot

best_match_rot_mg ( Image : : TemplateID, AngleStart, AngleExtend, MaxError, SubPixel, NumLevels : Row, Column, Angle, Error )

Searching the best matching of a template and a pyramid with rotation.

The operator best_match_rot_mg performs a matching of the template of TemplateID and Image. It works similar to best_match_mg with the extension that the pattern can be rotated analogously to best_match_rot. The parameters AngleStart and AngleExtend define the maximum rotation of the pattern: AngleStart specifies the maximum counter clockwise rotation and AngleExtend the maximum clockwise rotation relative to this angle. Both values have to smaller or equal to the values used for the creation of the pattern (see create_template_rot). In addition to best_match_mg best_match_rot_mg returns the rotion angle of the pattern in Angle (radiant).

The value of MaxError must be set larger in comparison with the operator best_match_rot, because often the error is larger at higher levels of the pyramid.

In the case of SubPixel = 'true' the position and the angle are calculated with “sub pixel” accuracy.

The value of NumLevels has to equal or smaller than the value used to create the template.

Parameters

`Image` (input_object)	image(-array) `->` object : byte
Input image inside of which the pattern has to be found.

`TemplateID` (input_control)	template `->` integer
Template number.

`AngleStart` (input_control)	angle.rad `->` real
Smallest Rotation of the pattern.
Default value: -0.39
Suggested values: -3.14, -1.57, -0.79, -0.39, -0.20, 0.0

`AngleExtend` (input_control)	angle.rad `->` real
Maximum positive Extension of `AngleStart`.
Default value: 0.79
Suggested values: 6.28, 3.14, 1.57, 0.79, 0.39
Restriction: `AngleExtend > 0`

`MaxError` (input_control)	real `->` real
Maximum average difference of the grayvalues.
Default value: 40
Suggested values: 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 15, 17, 20, 30, 40, 50, 60, 70
Typical range of values: `0 <= MaxError <= 255`
Minimum increment: 1
Recommended increment: 1

`SubPixel` (input_control)	string `->` string
Subpixel accuracy in case of 'true'.
Default value: 'false'
List of values: 'true', 'false'

`NumLevels` (input_control)	integer `->` integer
Number of the used resolution levels.
Default value: 3
List of values: 1, 2, 3, 4, 5, 6

`Row` (output_control)	point.y(-array) `->` real
Row position of the best match.

`Column` (output_control)	point.x(-array) `->` real
Column position of the best match.

`Angle` (output_control)	angle.rad(-array) `->` real
Rotation angle of pattern.

`Error` (output_control)	real(-array) `->` real
Average divergence of the grayvalues of the best match.

Result

If the parameter values are correct, the operator best_match_rot_mg returns the value 2 (H_MSG_TRUE). If the input is empty (no input images are available) the behaviour can be set via set_system('no_object_result',<Result>). If necessary, an exception handling is raised.

Parallelization Information

best_match_rot_mg is reentrant and automatically parallelized (on tuple level).

Possible Predecessors

create_template_rot, set_reference_template, set_offset_template, adapt_template, draw_region, draw_rectangle1, reduce_domain

Alternatives

best_match_rot, best_match_mg

See also

fast_match

Module

Matching

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