best_match_pre

best_match_pre_mg ( ImagePyramid : : TemplateID, MaxError, SubPixel, NumLevels, WhichLevels : Row, Column, Error )

Searching the best grayvalue matches in a pre generated pyramid.

best_match_pre_mg applies gray value matching using an image pyramid. best_match_pre_mg works analogously to best_match_mg, but it makes use of pre calculated pyramid which has to be generated beforehand using gen_gauss_pyramid. This reduces runtime if more than one match has to be done or the pyramid has be used otherwise. The pyramid has to be generated using the zooming factor 0.5 and the mode 'constant'.

Parameters

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

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

`MaxError` (input_control)	real `->` real
Maximal average difference of the grayvalues.
Default value: 30
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: 3

`SubPixel` (input_control)	string `->` string
Exactness in subpixels 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

`WhichLevels` (input_control)	integer `->` integer / string
Resolution level up to which the method ``best match'' is used.
Default value: 'original'
Suggested values: 'all', 'original', 0, 1, 2, 3, 4, 5, 6

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

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

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

Result

If the parameter values are correct, the operator best_match_pre_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_pre_mg is reentrant and processed without parallelization.

Possible Predecessors

gen_gauss_pyramid, create_template, read_template, adapt_template, draw_region, draw_rectangle1, reduce_domain, set_reference_template

Alternatives

fast_match, fast_match_mg, exhaustive_match, exhaustive_match_mg

Module

Matching