Operator Reference
exhaustive_match_mg (Operator)
exhaustive_match_mg — Matching a template and an image in a resolution pyramid.
Signature
exhaustive_match_mg(Image, ImageTemplate : ImageMatch : Mode, Level, Threshold : )
Description
The operator exhaustive_match_mg is an additional option for the
operator exhaustive_match performing a matching of the image
Image and the template ImageTemplate.
Hereby ImageTemplate will be moved over all points
of the region of Image, a matching criterion will be
calculated with regard to the parameter Mode
and the result values will be stored in ImageMatch.
Of images having been filtered this way, normally only those areas
with good matching results are of interest. The size of the area to
be searched, i.e. the region of the input image Image,
determines decisively the runtime of the matching filter.
Therefore it is recommendable to use at first exhaustive_match_mg
with reduced image resolution in order to determine a
“region of interest” in which good matching results can be expected;
then in this restricted area only the real matching (see also
exhaustive_match) will be executed with normal resolution.
Hereby the Gauss-pyramids of Image and ImageTemplate
will be composed (in particular the corresponding regions will be
transformed as well). Then on each level of the resolution pyramids -
starting with the startlevel Level - the matching inside
the current “region of interest” will be executed. Whereby the
“region of interest” on the startlevel is equivalent to the
region of the input image Image.
After the filtering, a new “region of interest” is determined with
the help of a threshold operation and will be transformed on the
next resolution level:
threshold(...:...:0,Threshold,...:), if Mode = 'dfd' threshold(...:...:Threshold,255,...:), if Mode = 'norm_correlation'
The final matching in the determined “region of interest” will then be
calculated with the highest resolution (Level 0).
The output image ImageMatch includes the corresponding
filter result and the final “region of interest”, which
is determined on the result image with the help of a threshold operation.
The operator exhaustive_match_mg therefore is not simply
a filter, but can also be considered as a member of the class of region
transformations.
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
Image (input_object) singlechannelimage(-array) → object (byte)
Input image.
ImageTemplate (input_object) singlechannelimage → object (byte)
The domain of this image will be
matched with Image.
ImageMatch (output_object) image(-array) → object (byte)
Result image and result region: values of the matching criterion within the determined “region of interest”.
Number of elements: ImageMatch == Image
Mode (input_control) string → (string)
Desired matching criterion.
Default: 'dfd'
List of values: 'dfd', 'norm_correlation'
Level (input_control) integer → (integer)
Startlevel in the resolution pyramid (highest resolution: Level 0).
Default: 1
Suggested values: 0, 1, 2, 3, 4, 5, 6, 7, 8
Restriction:
Level <= ld(width(Image)) && Level <= ld(height(Image)) && Level <= ld(width(ImageTemplate)) && Level <= ld(height(ImageTemplate))
Threshold (input_control) integer → (integer)
Threshold to determine the “region of interest”.
Default: 30
Suggested values: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250
Value range:
0
≤
Threshold
≤
255
Minimum increment: 1
Recommended increment: 5
Example (C)
read_image(&Image,"monkey"); disp_image(Image,WindowHandle); draw_rectangle2(WindowHandle,&Row,&Column,&Phi,&Length1,&Length2); gen_rectangle2(&Rectangle,Row,Column,Phi,Length1,Length2); reduce_domain(Image,Rectangle,&Template); exhaustive_match_mg(Image,Template,&ImageMatch,'dfd'1,30); invert_image(ImageMatch,&ImageInvert); local_max(ImageInvert,&BestFit); disp_region(BestFit,WindowHandle);
Result
If the parameter values are correct, the operator
exhaustive_match_mg 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>).
If necessary, an exception is raised.
Possible Predecessors
Possible Successors
Alternatives
See also
Module
Foundation