exhaustive_match_mgexhaustive_match_mgExhaustiveMatchMgExhaustiveMatchMg (Operator)

Name

exhaustive_match_mgexhaustive_match_mgExhaustiveMatchMgExhaustiveMatchMg — 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_mgexhaustive_match_mgExhaustiveMatchMgExhaustiveMatchMgExhaustiveMatchMg is an additional option for the operator exhaustive_matchexhaustive_matchExhaustiveMatchExhaustiveMatchExhaustiveMatch performing a matching of the image ImageImageImageImageimage and the template ImageTemplateImageTemplateImageTemplateImageTemplateimageTemplate. Hereby ImageTemplateImageTemplateImageTemplateImageTemplateimageTemplate will be moved over all points of the region of ImageImageImageImageimage, a matching criterion will be calculated with regard to the parameter ModeModeModeModemode and the result values will be stored in ImageMatchImageMatchImageMatchImageMatchimageMatch.

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 ImageImageImageImageimage, determines decisively the runtime of the matching filter. Therefore it is recommendable to use at first exhaustive_match_mgexhaustive_match_mgExhaustiveMatchMgExhaustiveMatchMgExhaustiveMatchMg 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_matchexhaustive_matchExhaustiveMatchExhaustiveMatchExhaustiveMatch) will be executed with normal resolution.

Hereby the Gauss-pyramids of ImageImageImageImageimage and ImageTemplateImageTemplateImageTemplateImageTemplateimageTemplate 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 LevelLevelLevelLevellevel - 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 ImageImageImageImageimage. 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 (LevelLevelLevelLevellevel 0). The output image ImageMatchImageMatchImageMatchImageMatchimageMatch 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_mgexhaustive_match_mgExhaustiveMatchMgExhaustiveMatchMgExhaustiveMatchMg 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

ImageImageImageImageimage (input_object) singlechannelimage(-array) → object (byte)

Input image.

ImageTemplateImageTemplateImageTemplateImageTemplateimageTemplate (input_object) singlechannelimage → object (byte)

The domain of this image will be matched with ImageImageImageImageimage.

ImageMatchImageMatchImageMatchImageMatchimageMatch (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

ModeModeModeModemode (input_control) string → (string)

Desired matching criterion.

Default value: 'dfd' "dfd" "dfd" "dfd" "dfd"

List of values: 'dfd'"dfd""dfd""dfd""dfd", 'norm_correlation'"norm_correlation""norm_correlation""norm_correlation""norm_correlation"

LevelLevelLevelLevellevel (input_control) integer → (integer)

Startlevel in the resolution pyramid (highest resolution: Level 0).

Default value: 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))

ThresholdThresholdThresholdThresholdthreshold (input_control) integer → (integer)

Threshold to determine the “region of interest”.

Default value: 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

Typical range of values: 0 ≤ Threshold Threshold Threshold Threshold 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_mgexhaustive_match_mgExhaustiveMatchMgExhaustiveMatchMgExhaustiveMatchMg 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>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>). If necessary, an exception is raised.