set_shape_model_clutterSetShapeModelClutterSetShapeModelClutterset_shape_model_clutterT_set_shape_model_clutter🔗

Short description🔗

set_shape_model_clutterSetShapeModelClutterSetShapeModelClutterset_shape_model_clutterT_set_shape_model_clutter — Set the clutter parameters of a shape model.

Signature🔗

set_shape_model_clutter( region ClutterRegion, shape_model ModelID, hom_mat2d HomMat2D, number ClutterContrast, attribute.name GenParamName, attribute.value GenParamValue )

Description🔗

set_shape_model_clutterSetShapeModelClutter sets the clutter parameters of the shape model ModelIDmodelIDmodel_id. In particular, a region is defined relative to the model contours, in which no (or too faint) clutter edges should occur in the search image. This is helpful, e.g., if it is a special characteristic of the model that, in specific parts near to the model, structures are missing.

For example, within the HDevelop example program find_shape_model_clutter.hdev, the model corresponds to a ball in a ball grid array (BGA). As the ball grid array represents a repeating pattern, many matches are returned when matching is applied without considering the neighborhood of the model. By defining a clutter region, the search can be restricted to specific instances of the model.



(1)	(2)	(3)	(4)	(5)

(1) Image of ball grid array, (2) shape model of a single ball of the array (orange), (3) matching result without using clutter parameters (green), (4) defining the clutter region (yellow) relative to the model (orange), (5) matching result using clutter parameters (green).

For matches found in a search image, edges within the clutter region increase the resulting clutter scores. These are returned by find_shape_modelFindShapeModel, find_scaled_shape_modelFindScaledShapeModel, find_aniso_shape_modelFindAnisoShapeModel, find_shape_modelsFindShapeModels, find_scaled_shape_modelsFindScaledShapeModels, and find_aniso_shape_modelsFindAnisoShapeModels in the parameter Scorescorescore, following the common values measuring how much of the model is visible in the image. Note that the input parameter MinScoreminScoremin_score of those operators additionally expects information specifying the maximum clutter score up to which matches should be returned. For more information regarding the setting of MinScoreminScoremin_score, please refer to the respective operator reference.

To define the clutter region relative to the model contours, you need the region ClutterRegionclutterRegionclutter_region and the transformation matrix HomMat2DhomMat2Dhom_mat_2d that maps the model contours to the respective position where the object appears in an image. Typically, you obtain them by searching for a model instance in an image, e.g., with the operator find_shape_modelFindShapeModel. Then, the transformation matrix can be determined with the procedure get_hom_mat2d_from_matching_result using the respective output parameters of the search. The region ClutterRegionclutterRegionclutter_region is specified within the same image. Note that ClutterRegionclutterRegionclutter_region should contain the regions around the superfluous edges that are typical for all expected manifestations of the matches. We recommend that the clutter region is chosen larger than necessary when large scale ranges are searched. Furthermore, choosing the clutter region not too near to the expected model contours can increase the robustness.

The parameter ClutterContrastclutterContrastclutter_contrast determines the contrast the edges in the clutter region must have in order to be counted as clutter. In many applications, the parameter Contrastcontrastcontrast, which has been used to create the shape model, is also a reasonable choice for ClutterContrastclutterContrastclutter_contrast. ClutterContrastclutterContrastclutter_contrast may not be smaller than the parameter MinContrastminContrastmin_contrast of the shape model, otherwise an error is raised at runtime. The polarity of the found clutter edges is ignored, i.e., bright objects on a dark background will yield the same clutter score as dark objects on a bright background, independent of the parameter Metricmetricmetric of the shape model. Please note that of all shape-based matching results, clutter scores are affected the most when a variation of illumination occurs.

With GenParamNamegenParamNamegen_param_name set to 'clutter_border_mode'"clutter_border_mode", the behavior of the clutter score can be influenced in cases where the clutter region of a found match is not entirely contained in the image domain. The corresponding values for 'clutter_border_mode'"clutter_border_mode" (GenParamValuegenParamValuegen_param_value) can be 'clutter_border_average'"clutter_border_average" or 'clutter_border_empty'"clutter_border_empty".

'clutter_border_average'"clutter_border_average":

When GenParamValuegenParamValuegen_param_value is set to 'clutter_border_average'"clutter_border_average" (default), the hidden part of the clutter region is assumed to be filled on average as is its visible part. If the clutter region is not visible at all, the clutter score of the found match is set to 0.00.0.
'clutter_border_empty'"clutter_border_empty":

When GenParamValuegenParamValuegen_param_value is set to 'clutter_border_empty'"clutter_border_empty", the clutter region is assumed to be empty where it is not visible.

Note that GenParamValuegenParamValuegen_param_value set to 'clutter_border_average'"clutter_border_average" results in higher clutter scores even if the match is not located at the border of the image domain.

The use of clutter parameters can be disabled and enabled by calling set_shape_model_paramSetShapeModelParam. For newly created shape models, the use of clutter parameters is disabled. After calling set_shape_model_clutterSetShapeModelClutter, the use of clutter parameters is enabled. Depending on the activation status for the use of clutter parameters, the find operators, e.g., find_shape_modelFindShapeModel, expect a different number of entries in the input parameter MinScoreminScoremin_score. The set clutter parameters and the value of 'use_clutter'"use_clutter" can be queried using the operator get_shape_model_clutterGetShapeModelClutter.

Execution information🔗

Execution information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

This operator modifies the state of the following input parameter:

ModelIDmodelIDmodel_id

During execution of this operator, access to the value of this parameter must be synchronized if it is used across multiple threads.

Parameters🔗

ClutterRegionclutterRegionclutter_region (input_object) region → objectHObjectHRegionHObjectHobject

Region where no clutter should occur.

ModelIDmodelIDmodel_id (input_control, state is modified) shape_model → (handle)HTuple (HHandle)HShapeModel, HTuple (IntPtr)HHandleHtuple (handle)

Handle of the model.

HomMat2DhomMat2Dhom_mat_2d (input_control) hom_mat2d → (real)HTuple (double)HHomMat2D, HTuple (double)Sequence[float]Htuple (double)

Transformation matrix.

ClutterContrastclutterContrastclutter_contrast (input_control) number → (integer)HTuple (Hlong)HTuple (int / long)intHtuple (Hlong)

Minimum contrast of clutter in the search images.

Default: 128128

GenParamNamegenParamNamegen_param_name (input_control) attribute.name(-array) → (string)HTuple (HString)HTuple (string)MaybeSequence[str]Htuple (char*)

Parameter names.

List of values: 'clutter_border_mode'"clutter_border_mode"

GenParamValuegenParamValuegen_param_value (input_control) attribute.value(-array) → (real / integer / string)HTuple (double / Hlong / HString)HTuple (double / int / long / string)MaybeSequence[Union[float, int, str]]Htuple (double / Hlong / char*)

Parameter values.

List of values: 'clutter_border_average', 'clutter_border_empty'

Example🔗

(HDevelop)

*
* Create a shape model.
read_image (ImageModel, '/bga_gap/bga_gap_01.png')
gen_circle (ROI, 753.869, 551.624, 28.4027)
reduce_domain (ImageModel, ROI, ImageReduced)
create_aniso_shape_model (ImageReduced, 'auto', rad(0), rad(0), 'auto', \
                          0.95, 1.05, 'auto', 0.95, 1.05, 'auto', 'auto', \
                          'use_polarity', 'auto', 'auto', ModelID)
*
* Specify the clutter parameters.
find_aniso_shape_model (ImageModel, ModelID, rad(0), rad(0), 0.95, 1.05, \
                        0.95, 1.05, 0.83, 0, 0.0, 'least_squares', 0, 0.0, \
                        Row, Column, Angle, ScaleR, ScaleC, Score)
get_hom_mat2d_from_matching_result (Row[0], Column[0], Angle[0], ScaleR[0], \
                                    ScaleC[0], HomMat2D)
*
gen_circle (ROI_0, 700.655, 548.666, 21.6273)
gen_circle (ROI_1_0, 810.655, 550.611, 21.6273)
union2 (ROI_0, ROI_1_0, ClutterRegion)
*
ClutterContrast := 12
*
* Set the clutter parameters into shape model.
set_shape_model_clutter (ClutterRegion, ModelID, HomMat2D, ClutterContrast, \
                         [], [])
*
* Use the shape model to detect objects with a small amount of clutter
read_image (Image,'/bga_gap/bga_gap_02.png')
MaxClutter := 0.09
find_aniso_shape_model (Image, ModelID, rad(0), rad(0), 0.95, 1.05, 0.95, \
                        1.05, [0.83, MaxClutter], 0, 0.0, 'least_squares', \
                        [4, 3],  0.0,  Row, Column, Angle, ScaleR, ScaleC, \
                        Score)
*
* Visualize the matches
dev_display_shape_matching_results (ModelID, ['green', 'red'], Row, Column, \
                                    Angle, ScaleR, ScaleC, 0)
Clutter := Score[|Score|/2:|Score|-1]
Score := Score[0:|Score|/2-1]
dev_inspect_ctrl ([Score, Clutter])

Result🔗

If the parameters are valid, the operator set_shape_model_clutterSetShapeModelClutter returns the value 2 (H_MSG_TRUE). If necessary an exception is raised.

Combinations with other operators🔗

Combinations

Possible predecessors

create_shape_modelCreateShapeModel, create_scaled_shape_modelCreateScaledShapeModel, create_aniso_shape_modelCreateAnisoShapeModel, create_shape_model_xldCreateShapeModelXld, create_scaled_shape_model_xldCreateScaledShapeModelXld, create_aniso_shape_model_xldCreateAnisoShapeModelXld

Possible successors

find_shape_modelFindShapeModel, find_scaled_shape_modelFindScaledShapeModel, find_aniso_shape_modelFindAnisoShapeModel, find_shape_modelsFindShapeModels, find_scaled_shape_modelsFindScaledShapeModels, find_aniso_shape_modelsFindAnisoShapeModels, get_shape_model_clutterGetShapeModelClutter

Alternatives

set_generic_shape_model_paramSetGenericShapeModelParam, set_generic_shape_model_objectSetGenericShapeModelObject

See also

set_shape_model_paramSetShapeModelParam

Module🔗

Matching