fast_matchT_fast_matchFastMatchFastMatchfast_match (Operator)

Name

fast_matchT_fast_matchFastMatchFastMatchfast_match — Searching all good matches of a template and an image.

Warning

fast_matchfast_matchFastMatchFastMatchfast_match is obsolete and is only provided for reasons of backward compatibility. New applications should use the shape-based or NCC-based operators instead.

Signature

Description

The operator fast_matchfast_matchFastMatchFastMatchfast_match performs a matching of the template of TemplateIDTemplateIDTemplateIDtemplateIDtemplate_id and ImageImageImageimageimage. Hereby the template will be moved over the points of ImageImageImageimageimage so that the template always lies completely inside of ImageImageImageimageimage. The matching criterion (“displaced frame difference”) is defined as follows: The difference between fast_matchfast_matchFastMatchFastMatchfast_match and exhaustive_matchexhaustive_matchExhaustiveMatchExhaustiveMatchexhaustive_match is that the matching for one position is stopped if the error is too high. This leads to a reduced runtime but one might miss correct matches. The runtime of the operator depends mainly on the size of the domain of ImageImageImageimageimage. Therefore it is important to restrict the domain as far as possible, i.e. to apply the operator only in a very confined “region of interest”. The parameter MaxErrorMaxErrorMaxErrormaxErrormax_error determines the maximal error which the searched position is allowed to show. The lower this value is, the faster the operator runs.

All points which show a matching error smaller than MaxErrorMaxErrorMaxErrormaxErrormax_error will be returned in the output region MatchesMatchesMatchesmatchesmatches. This region can be used for further processing. For example by using a connection and best_matchbest_matchBestMatchBestMatchbest_match to find all the matching objects. If no point has a match error below MaxErrorMaxErrorMaxErrormaxErrormax_error the empty region (i.e no points) is returned.

Execution Information

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Automatically parallelized on tuple level.

Parameters

Result

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

Possible Predecessors

create_templatecreate_templateCreateTemplateCreateTemplatecreate_template, read_templateread_templateReadTemplateReadTemplateread_template, adapt_templateadapt_templateAdaptTemplateAdaptTemplateadapt_template, draw_regiondraw_regionDrawRegionDrawRegiondraw_region, draw_rectangle1draw_rectangle1DrawRectangle1DrawRectangle1draw_rectangle1, reduce_domainreduce_domainReduceDomainReduceDomainreduce_domain

Possible Successors

connectionconnectionConnectionConnectionconnection, best_matchbest_matchBestMatchBestMatchbest_match

Alternatives

best_matchbest_matchBestMatchBestMatchbest_match, best_match_mgbest_match_mgBestMatchMgBestMatchMgbest_match_mg, fast_match_mgfast_match_mgFastMatchMgFastMatchMgfast_match_mg, exhaustive_matchexhaustive_matchExhaustiveMatchExhaustiveMatchexhaustive_match, exhaustive_match_mgexhaustive_match_mgExhaustiveMatchMgExhaustiveMatchMgexhaustive_match_mg

Module

Matching