fast_match — Searching all good matches of a template and an image.
fast_match is obsolete and is only provided for reasons of backward compatibility. New applications should use the shape-based or NCC-based operators instead.
The operator fast_match performs a matching of the template of TemplateID and Image. Hereby the template will be moved over the points of Image so that the template always lies completely inside of Image. The matching criterion (“displaced frame difference”) is defined as follows:
All points which show a matching error smaller than MaxError will be returned in the output region Matches. This region can be used for further processing. For example by using a connection and best_match to find all the matching objects. If no point has a match error below MaxError the empty region (i.e no points) is returned.
Input image inside of which the pattern has to be found.
All points whose error lies below a certain threshold.
Maximal average difference of the grayvalues.
Default value: 20.0
Suggested values: 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 9.0, 11.0, 15.0, 17.0, 20.0, 30.0
Typical range of values: 0 ≤ MaxError ≤ 255
Minimum increment: 1
Recommended increment: 1
If the parameter values are correct, the operator fast_match 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 is raised.
create_template, read_template, adapt_template, draw_region, draw_rectangle1, reduce_domain
best_match, best_match_mg, fast_match_mg, exhaustive_match, exhaustive_match_mg