polar_trans_region_invpolar_trans_region_invPolarTransRegionInvPolarTransRegionInvpolar_trans_region_inv (Operator)

Name

polar_trans_region_invpolar_trans_region_invPolarTransRegionInvPolarTransRegionInvpolar_trans_region_inv — Transform a region in polar coordinates back to Cartesian coordinates.

Signature

Description

polar_trans_region_invpolar_trans_region_invPolarTransRegionInvPolarTransRegionInvpolar_trans_region_inv transforms the polar coordinate representation of a region, stored in PolarRegionPolarRegionPolarRegionpolarRegionpolar_region, back onto an annular arc in Cartesian coordinates, described by the radii RadiusStartRadiusStartRadiusStartradiusStartradius_start and RadiusEndRadiusEndRadiusEndradiusEndradius_end and the angles AngleStartAngleStartAngleStartangleStartangle_start and AngleEndAngleEndAngleEndangleEndangle_end with the center point located at (RowRowRowrowrow, ColumnColumnColumncolumncolumn). All of these values can be chosen as real numbers. In addition, the dimensions of the virtual image containing the region PolarRegionPolarRegionPolarRegionpolarRegionpolar_region must be given in WidthInWidthInWidthInwidthInwidth_in and HeightInHeightInHeightInheightInheight_in. WidthInWidthInWidthInwidthInwidth_in-1 is the column coordinate corresponding to AngleEndAngleEndAngleEndangleEndangle_end and HeightInHeightInHeightInheightInheight_in-1 is the row coordinate corresponding to RadiusEndRadiusEndRadiusEndradiusEndradius_end. AngleStartAngleStartAngleStartangleStartangle_start and RadiusStartRadiusStartRadiusStartradiusStartradius_start correspond to column and row coordinate 0. Furthermore, the dimensions WidthWidthWidthwidthwidth and HeightHeightHeightheightheight of the virtual output image containing the transformed region XYTransRegionXYTransRegionXYTransRegionXYTransRegionxytrans_region are required.

The angles and radii are inclusive, which means that the row coordinate 0 in PolarRegionPolarRegionPolarRegionpolarRegionpolar_region will be mapped onto a a circle with a distance of RadiusStartRadiusStartRadiusStartradiusStartradius_start pixels from the specified center and the row with the coordinate HeightInHeightInHeightInheightInheight_in-1 will be mapped onto a circle of radius RadiusEndRadiusEndRadiusEndradiusEndradius_end. This applies to AngleStartAngleStartAngleStartangleStartangle_start, AngleEndAngleEndAngleEndangleEndangle_end, and WidthInWidthInWidthInwidthInwidth_in in an analogous way. If the width of the input region PolarRegionPolarRegionPolarRegionpolarRegionpolar_region corresponds to an angle interval greater than 2pi, the region is cropped such that length of this interval is 2pi.

The parameter InterpolationInterpolationInterpolationinterpolationinterpolation is used to select the interpolation method 'bilinear'"bilinear""bilinear""bilinear""bilinear" or 'nearest_neighbor'"nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor". Setting InterpolationInterpolationInterpolationinterpolationinterpolation to 'bilinear'"bilinear""bilinear""bilinear""bilinear" leads to smoother region boundaries, especially if regions are enlarged. However, the runtime increases significantly.

polar_trans_region_invpolar_trans_region_invPolarTransRegionInvPolarTransRegionInvpolar_trans_region_inv is the inverse function of polar_trans_regionpolar_trans_regionPolarTransRegionPolarTransRegionpolar_trans_region.

The call sequence: returns the region RegionRegionRegionregionregion, restricted to the circle around (RowRowRowrowrow, ColumnColumnColumncolumncolumn) with radius RadiusRadiusRadiusradiusradius, as its output region XYTransRegionXYTransRegionXYTransRegionXYTransRegionxytrans_region.

If more than one region is passed in PolarRegionPolarRegionPolarRegionpolarRegionpolar_region, their Cartesian transformations are computed individually and stored as a tuple in XYTransRegionXYTransRegionXYTransRegionXYTransRegionxytrans_region. Please note that the indices of an input region and its transformation only correspond if the system variable 'store_empty_regions'"store_empty_regions""store_empty_regions""store_empty_regions""store_empty_regions" is set to 'false'"false""false""false""false" (see set_systemset_systemSetSystemSetSystemset_system). Otherwise empty output regions are discarded and the length of the input tuple PolarRegionPolarRegionPolarRegionpolarRegionpolar_region is most likely not equal to the length of the output tuple XYTransRegionXYTransRegionXYTransRegionXYTransRegionxytrans_region.

Further Information

For an explanation of the different 2D coordinate systems used in HALCON, see the introduction of chapter Transformations / 2D Transformations.

Attention

If WidthWidthWidthwidthwidth or HeightHeightHeightheightheight are chosen greater than the dimensions of the current image, the system variable 'clip_region'"clip_region""clip_region""clip_region""clip_region" should be set to 'false'"false""false""false""false" (see set_systemset_systemSetSystemSetSystemset_system). Otherwise, an output region that does not lie within the dimensions of the current image can produce an error message.

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.
• Automatically parallelized on internal data level.

Parameters

See also

polar_trans_image_extpolar_trans_image_extPolarTransImageExtPolarTransImageExtpolar_trans_image_ext, polar_trans_image_invpolar_trans_image_invPolarTransImageInvPolarTransImageInvpolar_trans_image_inv, polar_trans_regionpolar_trans_regionPolarTransRegionPolarTransRegionpolar_trans_region, polar_trans_contour_xldpolar_trans_contour_xldPolarTransContourXldPolarTransContourXldpolar_trans_contour_xld, polar_trans_contour_xld_invpolar_trans_contour_xld_invPolarTransContourXldInvPolarTransContourXldInvpolar_trans_contour_xld_inv

Module

Foundation

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