HALCON 19.05.0.0 / HALCON Operator Reference / Filters / Geometric Transformations
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polar_trans_image_extpolar_trans_image_extPolarTransImageExtPolarTransImageExt (Operator)

Name

polar_trans_image_extpolar_trans_image_extPolarTransImageExtPolarTransImageExt — Transform an annular arc in an image to polar coordinates.

Signature

polar_trans_image_ext(Image : PolarTransImage : Row, Column, AngleStart, AngleEnd, RadiusStart, RadiusEnd, Width, Height, Interpolation : )

Herror polar_trans_image_ext(const Hobject Image, Hobject* PolarTransImage, double Row, double Column, double AngleStart, double AngleEnd, double RadiusStart, double RadiusEnd, const Hlong Width, const Hlong Height, const char* Interpolation)

Herror T_polar_trans_image_ext(const Hobject Image, Hobject* PolarTransImage, const Htuple Row, const Htuple Column, const Htuple AngleStart, const Htuple AngleEnd, const Htuple RadiusStart, const Htuple RadiusEnd, const Htuple Width, const Htuple Height, const Htuple Interpolation)

void PolarTransImageExt(const HObject& Image, HObject* PolarTransImage, const HTuple& Row, const HTuple& Column, const HTuple& AngleStart, const HTuple& AngleEnd, const HTuple& RadiusStart, const HTuple& RadiusEnd, const HTuple& Width, const HTuple& Height, const HTuple& Interpolation)

HImage HImage::PolarTransImageExt(const HTuple& Row, const HTuple& Column, double AngleStart, double AngleEnd, const HTuple& RadiusStart, const HTuple& RadiusEnd, Hlong Width, Hlong Height, const HString& Interpolation) const

HImage HImage::PolarTransImageExt(double Row, double Column, double AngleStart, double AngleEnd, double RadiusStart, double RadiusEnd, Hlong Width, Hlong Height, const HString& Interpolation) const

HImage HImage::PolarTransImageExt(double Row, double Column, double AngleStart, double AngleEnd, double RadiusStart, double RadiusEnd, Hlong Width, Hlong Height, const char* Interpolation) const

HImage HImage::PolarTransImageExt(double Row, double Column, double AngleStart, double AngleEnd, double RadiusStart, double RadiusEnd, Hlong Width, Hlong Height, const wchar_t* Interpolation) const   (Windows only)

static void HOperatorSet.PolarTransImageExt(HObject image, out HObject polarTransImage, HTuple row, HTuple column, HTuple angleStart, HTuple angleEnd, HTuple radiusStart, HTuple radiusEnd, HTuple width, HTuple height, HTuple interpolation)

HImage HImage.PolarTransImageExt(HTuple row, HTuple column, double angleStart, double angleEnd, HTuple radiusStart, HTuple radiusEnd, int width, int height, string interpolation)

HImage HImage.PolarTransImageExt(double row, double column, double angleStart, double angleEnd, double radiusStart, double radiusEnd, int width, int height, string interpolation)

Description

polar_trans_image_extpolar_trans_image_extPolarTransImageExtPolarTransImageExtPolarTransImageExt transforms the annular arc specified by the center point (RowRowRowRowrow, ColumnColumnColumnColumncolumn), the radii RadiusStartRadiusStartRadiusStartRadiusStartradiusStart and RadiusEndRadiusEndRadiusEndRadiusEndradiusEnd and the angles AngleStartAngleStartAngleStartAngleStartangleStart and AngleEndAngleEndAngleEndAngleEndangleEnd in the image ImageImageImageImageimage to its polar coordinate version in the image PolarTransImagePolarTransImagePolarTransImagePolarTransImagepolarTransImage of the dimensions WidthWidthWidthWidthwidth x HeightHeightHeightHeightheight.

The upper left pixel in the output image always corresponds to the point in the input image that is specified by RadiusStartRadiusStartRadiusStartRadiusStartradiusStart and AngleStartAngleStartAngleStartAngleStartangleStart. Analogously, the lower right pixel in the output image always corresponds to the point in the input image that is specified by RadiusEndRadiusEndRadiusEndRadiusEndradiusEnd and AngleEndAngleEndAngleEndAngleEndangleEnd. In the usual mode (AngleStartAngleStartAngleStartAngleStartangleStart < AngleEndAngleEndAngleEndAngleEndangleEnd and RadiusStartRadiusStartRadiusStartRadiusStartradiusStart < RadiusEndRadiusEndRadiusEndRadiusEndradiusEnd), the polar transformation is performed in the mathematically positive orientation (counterclockwise). Furthermore, points with smaller radii lie in the upper part of the output image. By suitably exchanging the values of these parameters (e.g., AngleStartAngleStartAngleStartAngleStartangleStart > AngleEndAngleEndAngleEndAngleEndangleEnd or RadiusStartRadiusStartRadiusStartRadiusStartradiusStart > RadiusEndRadiusEndRadiusEndRadiusEndradiusEnd), any desired orientation of the output image can be achieved.

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". With 'nearest_neighbor'"nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor", the gray value of a pixel in the output image is determined by the gray value of the closest pixel in the input image. With 'bilinear'"bilinear""bilinear""bilinear""bilinear", the gray value of a pixel in the output image is determined by bilinear interpolation of the gray values of the four closest pixels in the input image. The mode 'bilinear'"bilinear""bilinear""bilinear""bilinear" results in images of better quality, but is slower than the mode 'nearest_neighbor'"nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor".

The angles can be chosen from all real numbers. Center point and radii can be real as well. However, if they are both integers and the difference of RadiusEndRadiusEndRadiusEndRadiusEndradiusEnd and RadiusStartRadiusStartRadiusStartRadiusStartradiusStart equals the height HeightHeightHeightHeightheight of the destination image, calculation will be sped up through an optimized routine.

The radii and angles are inclusive, which means that the first row of the target image contains the circle with radius RadiusStartRadiusStartRadiusStartRadiusStartradiusStart and the last row contains the circle with radius RadiusEndRadiusEndRadiusEndRadiusEndradiusEnd. For complete circles, where the difference between AngleStartAngleStartAngleStartAngleStartangleStart and AngleEndAngleEndAngleEndAngleEndangleEnd equals (360 degrees), this also means that the first column of the target image will be the same as the last.

To avoid this, do not make this difference , but degrees instead.

The call: polar_trans_image(Image, PolarTransImage, Row, Column, Width, Height) produces the same result as the call: polar_trans_image_ext(Image, PolarTransImage, Row-0.5, Column-0.5, 6.2831853, 6.2831853/Width, 0, Height-1, Width, Height, 'nearest_neighbor')

The offset of 0.5 is necessary since polar_trans_imagepolar_trans_imagePolarTransImagePolarTransImagePolarTransImage does not do exact nearest neighbor interpolation and the radii and angles can be calculated using the information in the above paragraph and knowing that polar_trans_imagepolar_trans_imagePolarTransImagePolarTransImagePolarTransImage does not handle its arguments inclusively. The start angle is bigger than the end angle to make polar_trans_image_extpolar_trans_image_extPolarTransImageExtPolarTransImageExtPolarTransImageExt go clockwise, just like polar_trans_imagepolar_trans_imagePolarTransImagePolarTransImagePolarTransImage does.

polar_trans_image_extpolar_trans_image_extPolarTransImageExtPolarTransImageExtPolarTransImageExt can be executed on an OpenCL device if the input image does not exceed the maximum size of image objects of the selected device. Due to numerical reasons, there can be slight differences in the output compared to the execution on the CPU.

Additionally, for images of type 'byte'"byte""byte""byte""byte", 'int2'"int2""int2""int2""int2" or 'uint2'"uint2""uint2""uint2""uint2" the system parameter 'int_zooming'"int_zooming""int_zooming""int_zooming""int_zooming" selects between fast calculation in fixed point arithmetics ('int_zooming'"int_zooming""int_zooming""int_zooming""int_zooming" = 'true'"true""true""true""true") and highly accurate calculation in floating point arithmetics ('int_zooming'"int_zooming""int_zooming""int_zooming""int_zooming" = 'false'"false""false""false""false"). Fixed point calculation can lead to minor gray value deviations and pixels with undefined gray values.

Further Information

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

Attention

For speed reasons, the domain of the input image is ignored. The output image always has a complete rectangle as its domain.

Execution Information

Parameters

ImageImageImageImageimage (input_object)  (multichannel-)image(-array) → objectHImageHImageHobject (byte* / int2* / uint2* / real*) *allowed for compute devices

Input image.

PolarTransImagePolarTransImagePolarTransImagePolarTransImagepolarTransImage (output_object)  (multichannel-)image(-array) → objectHImageHImageHobject * (byte / int2 / uint2 / real)

Output image.

RowRowRowRowrow (input_control)  number → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Row coordinate of the center of the arc.

Default value: 256

Suggested values: 0, 16, 32, 64, 128, 240, 256, 480, 512

ColumnColumnColumnColumncolumn (input_control)  number → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Column coordinate of the center of the arc.

Default value: 256

Suggested values: 0, 16, 32, 64, 128, 256, 320, 512, 640

AngleStartAngleStartAngleStartAngleStartangleStart (input_control)  angle.rad → HTupleHTupleHtuple (real) (double) (double) (double)

Angle of the ray to be mapped to the first column of the output image.

Default value: 0.0

Suggested values: 0.0, 0.78539816, 1.57079632, 3.141592654, 6.2831853, 12.566370616

AngleEndAngleEndAngleEndAngleEndangleEnd (input_control)  angle.rad → HTupleHTupleHtuple (real) (double) (double) (double)

Angle of the ray to be mapped to the last column of the output image.

Default value: 6.2831853

Suggested values: 0.0, 0.78539816, 1.57079632, 3.141592654, 6.2831853, 12.566370616

RadiusStartRadiusStartRadiusStartRadiusStartradiusStart (input_control)  number → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Radius of the circle to be mapped to the first row of the output image.

Default value: 0

Suggested values: 0, 16, 32, 64, 100, 128, 256, 512

Typical range of values: 0 ≤ RadiusStart RadiusStart RadiusStart RadiusStart radiusStart

RadiusEndRadiusEndRadiusEndRadiusEndradiusEnd (input_control)  number → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Radius of the circle to be mapped to the last row of the output image.

Default value: 100

Suggested values: 0, 16, 32, 64, 100, 128, 256, 512

Typical range of values: 0 ≤ RadiusEnd RadiusEnd RadiusEnd RadiusEnd radiusEnd

WidthWidthWidthWidthwidth (input_control)  extent.x → HTupleHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Width of the output image.

Default value: 512

Suggested values: 256, 320, 512, 640, 800, 1024

Typical range of values: 0 ≤ Width Width Width Width width ≤ 32767

HeightHeightHeightHeightheight (input_control)  extent.y → HTupleHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

Height of the output image.

Default value: 512

Suggested values: 240, 256, 480, 512, 600, 1024

Typical range of values: 0 ≤ Height Height Height Height height ≤ 32767

InterpolationInterpolationInterpolationInterpolationinterpolation (input_control)  string → HTupleHTupleHtuple (string) (string) (HString) (char*)

Interpolation method for the transformation.

Default value: 'nearest_neighbor' "nearest_neighbor" "nearest_neighbor" "nearest_neighbor" "nearest_neighbor"

List of values: 'bilinear'"bilinear""bilinear""bilinear""bilinear", 'nearest_neighbor'"nearest_neighbor""nearest_neighbor""nearest_neighbor""nearest_neighbor"

See also

polar_trans_image_invpolar_trans_image_invPolarTransImageInvPolarTransImageInvPolarTransImageInv, polar_trans_regionpolar_trans_regionPolarTransRegionPolarTransRegionPolarTransRegion, polar_trans_region_invpolar_trans_region_invPolarTransRegionInvPolarTransRegionInvPolarTransRegionInv, polar_trans_contour_xldpolar_trans_contour_xldPolarTransContourXldPolarTransContourXldPolarTransContourXld, polar_trans_contour_xld_invpolar_trans_contour_xld_invPolarTransContourXldInvPolarTransContourXldInvPolarTransContourXldInv

Module

Foundation

ClassesClasses | | Operators
HALCON Operator Reference 19.05.0.0 Copyright © 1996-2019 MVTec Software GmbH