create_planar_uncalib_deformable_model_xldT_create_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld (Operator)

Name

create_planar_uncalib_deformable_model_xldT_create_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld — Prepare a deformable model for planar uncalibrated matching from XLD contours.

Signature

Description

The operator create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld creates a deformable model used for planar uncalibrated matching from the XLD contours passed in ContoursContoursContourscontourscontours. The XLD contours represent the gray-value edges of the object to be searched for. In contrast to the operator create_planar_uncalib_deformable_modelcreate_planar_uncalib_deformable_modelCreatePlanarUncalibDeformableModelCreatePlanarUncalibDeformableModelcreate_planar_uncalib_deformable_model, which creates a deformable model from a template image, the operator create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld creates the deformable model from XLD contours.

The model is generated for multiple image pyramid levels and is stored in memory. The center of gravity of the smallest surrounding rectangle of the ContoursContoursContourscontourscontours that is parallel to the coordinate axes is used as the origin (reference point) of the model. A different origin can be set with set_deformable_model_originset_deformable_model_originSetDeformableModelOriginSetDeformableModelOriginset_deformable_model_origin. The output parameter ModelIDModelIDModelIDmodelIDmodel_id is a handle for this model, which is used in subsequent calls to find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model.

Some Input parameters in detail

NumLevelsNumLevelsNumLevelsnumLevelsnum_levels:

The number of pyramid levels is determined with the parameter NumLevelsNumLevelsNumLevelsnumLevelsnum_levels. It should be chosen as large as possible because by this the time necessary to find the object is significantly reduced. On the other hand, NumLevelsNumLevelsNumLevelsnumLevelsnum_levels must be chosen such that the model is still recognizable and contains a sufficient number of points (at least four) on the highest pyramid level. If not enough model points are generated, the number of pyramid levels is reduced internally until enough model points are found on the highest pyramid level. If this procedure leads to a model with no pyramid levels, i.e., if the number of model points is already too small on the lowest pyramid level, create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld returns with an error message. If NumLevelsNumLevelsNumLevelsnumLevelsnum_levels is set to 'auto'"auto""auto""auto""auto", create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld determines the number of pyramid levels automatically. The computed number of pyramid levels can be queried using get_deformable_model_paramsget_deformable_model_paramsGetDeformableModelParamsGetDeformableModelParamsget_deformable_model_params. In rare cases, it might happen that create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld determines a value for the number of pyramid levels that is too large or too small. If the number of pyramid levels is chosen too large, the model may not be recognized in the search image or it may be necessary to select very low parameters for MinScoreMinScoreMinScoreminScoremin_score or GreedinessGreedinessGreedinessgreedinessgreediness in find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model to find the object. If the number of pyramid levels is chosen too small, the time required to find the object with find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model may increase. In both cases, the number of pyramid levels should be selected manually.

Angle and Scale parameters:

Note that the parameters AngleStartAngleStartAngleStartangleStartangle_start, AngleExtentAngleExtentAngleExtentangleExtentangle_extent, ScaleRMaxScaleRMaxScaleRMaxscaleRMaxscale_rmax, and ScaleCMaxScaleCMaxScaleCMaxscaleCMaxscale_cmax are not used by this operator. Instead, they have to be specified within the operator find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model. ScaleRMinScaleRMinScaleRMinscaleRMinscale_rmin and ScaleCMinScaleCMinScaleCMinscaleCMinscale_cmin can be relevant if you expect matches that are smaller than the given XLD ContoursContoursContourscontourscontours. Then, if NumLevelsNumLevelsNumLevelsnumLevelsnum_levels is set to 'auto'"auto""auto""auto""auto", the number of used pyramid levels may decrease.

Generally, the parameters AngleStepAngleStepAngleStepangleStepangle_step, ScaleRStepScaleRStepScaleRStepscaleRStepscale_rstep and ScaleCStepScaleCStepScaleCStepscaleCStepscale_cstep can be determined automatically. The automatically computed angle and scale step lengths can be queried using get_deformable_model_paramsget_deformable_model_paramsGetDeformableModelParamsGetDeformableModelParamsget_deformable_model_params. For more information about how these parameters work, please refer to the operator find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model.

OptimizationOptimizationOptimizationoptimizationoptimization:

For particularly large models, it may be useful to reduce the number of model points by setting OptimizationOptimizationOptimizationoptimizationoptimization to a value different from 'none'"none""none""none""none". If OptimizationOptimizationOptimizationoptimizationoptimization = 'none'"none""none""none""none" is set, all model points are stored. In all other cases, the number of points is reduced according to the value of OptimizationOptimizationOptimizationoptimizationoptimization. If the number of points is reduced, it may be necessary in find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model to set the parameter ScoreScoreScorescorescore and GreedinessGreedinessGreedinessgreedinessgreediness to a smaller value as, e.g., 0.7 or 0.8. For small models, the reduction of the number of model points does not result in a speed-up of the search, because in this case usually significantly more potential instances of the model must be examined. If OptimizationOptimizationOptimizationoptimizationoptimization is set to 'auto'"auto""auto""auto""auto", create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld automatically determines the reduction of the number of model points.

MinContrastMinContrastMinContrastminContrastmin_contrast:

With MinContrastMinContrastMinContrastminContrastmin_contrast, it can be determined which contrast the object contours must at least have in the recognition performed by find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model. In other words, this parameter separates the object from the noise in the image. Therefore, a good choice is the range of gray-value changes caused by the noise in the image. If, e.g., the gray values fluctuate within a range of 10 gray levels, MinContrastMinContrastMinContrastminContrastmin_contrast should be set to 10. If multi-channel images are used for the model and the search images, and if the parameter MetricMetricMetricmetricmetric is set to 'ignore_color_polarity'"ignore_color_polarity""ignore_color_polarity""ignore_color_polarity""ignore_color_polarity" (see below) the noise in one channel must be multiplied by the square root of the number of channels to determine MinContrastMinContrastMinContrastminContrastmin_contrast. If, e.g., the gray values fluctuate within a range of 10 gray levels in a single channel and the image is a three-channel image, MinContrastMinContrastMinContrastminContrastmin_contrast should be set to 17. If the model should be recognized in very low contrast images, MinContrastMinContrastMinContrastminContrastmin_contrast must be set to a correspondingly small value. If the model should be recognized even if it is severely occluded, MinContrastMinContrastMinContrastminContrastmin_contrast should be slightly larger than the range of gray value fluctuations created by noise to ensure that the position and rotation of the model are extracted robustly and accurately by find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model.

MetricMetricMetricmetricmetric:

The parameter MetricMetricMetricmetricmetric determines the conditions under which the model is recognized in the image. If MetricMetricMetricmetricmetric = 'use_polarity'"use_polarity""use_polarity""use_polarity""use_polarity", the object in the image and the model must have the same contrast. If, e.g., the model is a bright object on a dark background, the object is found only if it is also brighter than the background. If MetricMetricMetricmetricmetric = 'ignore_global_polarity'"ignore_global_polarity""ignore_global_polarity""ignore_global_polarity""ignore_global_polarity", the object is found in the image also if the contrast reverses globally. In the above example, the object hence is also found if it is darker than the background. The runtime of find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model will increase slightly in this case. If MetricMetricMetricmetricmetric = 'ignore_part_polarity'"ignore_part_polarity""ignore_part_polarity""ignore_part_polarity""ignore_part_polarity" or MetricMetricMetricmetricmetric = 'ignore_local_polarity'"ignore_local_polarity""ignore_local_polarity""ignore_local_polarity""ignore_local_polarity", the model is found even if the contrast changes locally. These modes can, e.g., be useful if the object consists of a part with a medium gray value, within which either darker or brighter sub-objects lie. The above mentioned four metrics can only be applied to single-channel images. If a multi-channel image is used as the search image, only the first channel will be used (and no error message will be returned). If MetricMetricMetricmetricmetric = 'ignore_color_polarity'"ignore_color_polarity""ignore_color_polarity""ignore_color_polarity""ignore_color_polarity", the model is found even if the color contrast changes locally. This is, e.g., the case if parts of the object can change their color, e.g., from red to green. In particular, this mode is useful if it is not known in advance in which channels the object is visible. In this mode, the runtime of find_planar_calib_deformable_modelfind_planar_calib_deformable_modelFindPlanarCalibDeformableModelFindPlanarCalibDeformableModelfind_planar_calib_deformable_model can also increase significantly. The metric 'ignore_color_polarity'"ignore_color_polarity""ignore_color_polarity""ignore_color_polarity""ignore_color_polarity" can be used for images with an arbitrary number of channels. If it is used for single-channel images, it has the same effect as 'ignore_local_polarity'"ignore_local_polarity""ignore_local_polarity""ignore_local_polarity""ignore_local_polarity". It should be noted that for MetricMetricMetricmetricmetric = 'ignore_color_polarity'"ignore_color_polarity""ignore_color_polarity""ignore_color_polarity""ignore_color_polarity" the channels do not need to contain a spectral subdivision of the light (like in an RGB image). The channels can, e.g., also contain images of the same object that were obtained by illuminating the object from different directions. Note that the first two metrics ('use_polarity'"use_polarity""use_polarity""use_polarity""use_polarity" and 'ignore_global_polarity'"ignore_global_polarity""ignore_global_polarity""ignore_global_polarity""ignore_global_polarity") can only be selected if all ContoursContoursContourscontourscontours provide the attribute 'edge_direction'"edge_direction""edge_direction""edge_direction""edge_direction", which defines the polarity of the contained contours. For more information about contour attributes like 'edge_direction'"edge_direction""edge_direction""edge_direction""edge_direction" see get_contour_attrib_xldget_contour_attrib_xldGetContourAttribXldGetContourAttribXldget_contour_attrib_xld. Otherwise, these two metrics can be selected with the operator set_planar_uncalib_deformable_model_metricset_planar_uncalib_deformable_model_metricSetPlanarUncalibDeformableModelMetricSetPlanarUncalibDeformableModelMetricset_planar_uncalib_deformable_model_metric, which determines the polarity of the model contours from a representative image.

Attention

Note that, in contrast to the operator create_planar_uncalib_deformable_modelcreate_planar_uncalib_deformable_modelCreatePlanarUncalibDeformableModelCreatePlanarUncalibDeformableModelcreate_planar_uncalib_deformable_model, it is not possible to specify a minimum size of the model components. To avoid small model components in the model, short contours can be eliminated before calling create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld with the operator select_contours_xldselect_contours_xldSelectContoursXldSelectContoursXldselect_contours_xld.

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 returns a handle. Note that the state of an instance of this handle type may be changed by specific operators even though the handle is used as an input parameter by those operators.

Parameters

Result

If the parameters are valid, the operator create_planar_uncalib_deformable_model_xldcreate_planar_uncalib_deformable_model_xldCreatePlanarUncalibDeformableModelXldCreatePlanarUncalibDeformableModelXldcreate_planar_uncalib_deformable_model_xld returns the value 2 ( H_MSG_TRUE) . If necessary, an exception is raised. If the parameter NumLevelsNumLevelsNumLevelsnumLevelsnum_levels is chosen such that the model contains too few points, the error 8510 is raised.

Possible Predecessors

read_contour_xld_dxfread_contour_xld_dxfReadContourXldDxfReadContourXldDxfread_contour_xld_dxf, edges_sub_pixedges_sub_pixEdgesSubPixEdgesSubPixedges_sub_pix, select_contours_xldselect_contours_xldSelectContoursXldSelectContoursXldselect_contours_xld

Possible Successors

find_planar_uncalib_deformable_modelfind_planar_uncalib_deformable_modelFindPlanarUncalibDeformableModelFindPlanarUncalibDeformableModelfind_planar_uncalib_deformable_model

See also

create_planar_uncalib_deformable_modelcreate_planar_uncalib_deformable_modelCreatePlanarUncalibDeformableModelCreatePlanarUncalibDeformableModelcreate_planar_uncalib_deformable_model

Module

Matching

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