HALCON 19.11.0.0 / HALCON Operator Reference / Transformations / 2D Transformations
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affine_trans_pixelT_affine_trans_pixelAffineTransPixelAffineTransPixel (Operator)

Name

affine_trans_pixelT_affine_trans_pixelAffineTransPixelAffineTransPixel — Apply an arbitrary affine 2D transformation to pixel coordinates.

Signature

affine_trans_pixel( : : HomMat2D, Row, Col : RowTrans, ColTrans)

Herror T_affine_trans_pixel(const Htuple HomMat2D, const Htuple Row, const Htuple Col, Htuple* RowTrans, Htuple* ColTrans)

void AffineTransPixel(const HTuple& HomMat2D, const HTuple& Row, const HTuple& Col, HTuple* RowTrans, HTuple* ColTrans)

void HHomMat2D::AffineTransPixel(const HTuple& Row, const HTuple& Col, HTuple* RowTrans, HTuple* ColTrans) const

void HHomMat2D::AffineTransPixel(double Row, double Col, double* RowTrans, double* ColTrans) const

static void HOperatorSet.AffineTransPixel(HTuple homMat2D, HTuple row, HTuple col, out HTuple rowTrans, out HTuple colTrans)

void HHomMat2D.AffineTransPixel(HTuple row, HTuple col, out HTuple rowTrans, out HTuple colTrans)

void HHomMat2D.AffineTransPixel(double row, double col, out double rowTrans, out double colTrans)

Description

affine_trans_pixelaffine_trans_pixelAffineTransPixelAffineTransPixelAffineTransPixel applies an arbitrary affine 2D transformation, i.e., scaling, rotation, translation, and slant (skewing), to the input pixels (RowRowRowRowrow,ColColColColcol) and returns the resulting pixels in (RowTransRowTransRowTransRowTransrowTrans,ColTransColTransColTransColTranscolTrans); the input and output pixels are subpixel precise coordinates. The affine transformation is described by the homogeneous transformation matrix given in HomMat2DHomMat2DHomMat2DHomMat2DhomMat2D.

In contrast to affine_trans_point_2daffine_trans_point_2dAffineTransPoint2dAffineTransPoint2dAffineTransPoint2d, affine_trans_pixelaffine_trans_pixelAffineTransPixelAffineTransPixelAffineTransPixel first converts the input coordinates from HALCON's standard coordinate system (with the origin in the center of the upper left pixel) to a coordinate system with the origin in the upper left corner of the upper left pixel. After the transformation with HomMat2DHomMat2DHomMat2DHomMat2DhomMat2D the result is converted back to the standard coordinate system. This way, affine_trans_pixelaffine_trans_pixelAffineTransPixelAffineTransPixelAffineTransPixel is compatible with affine_trans_imageaffine_trans_imageAffineTransImageAffineTransImageAffineTransImage, affine_trans_image_sizeaffine_trans_image_sizeAffineTransImageSizeAffineTransImageSizeAffineTransImageSize, affine_trans_regionaffine_trans_regionAffineTransRegionAffineTransRegionAffineTransRegion, affine_trans_contour_xldaffine_trans_contour_xldAffineTransContourXldAffineTransContourXldAffineTransContourXld, and affine_trans_polygon_xldaffine_trans_polygon_xldAffineTransPolygonXldAffineTransPolygonXldAffineTransPolygonXld.

Applying affine_trans_pixelaffine_trans_pixelAffineTransPixelAffineTransPixelAffineTransPixel corresponds to the following chain of transformations (input and output pixels as homogeneous vectors):

Hence,

affine_trans_pixel (HomMat2D, Row, Col, RowTrans, ColTrans) corresponds to the following operator sequence: affine_trans_point_2d (HomMat2D, Row+0.5, Col+0.5, RowTmp, ColTmp) RowTrans := RowTmp-0.5 ColTrans := ColTmp-0.5

Further Information

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

Execution Information

Parameters

HomMat2DHomMat2DHomMat2DHomMat2DhomMat2D (input_control)  hom_mat2d → HHomMat2D, HTupleHTupleHtuple (real) (double) (double) (double)

Input transformation matrix.

RowRowRowRowrow (input_control)  point.x(-array) → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Input pixel(s) (row coordinate).

Default value: 64

Suggested values: 0, 16, 32, 64, 128, 256, 512, 1024

ColColColColcol (input_control)  point.y(-array) → HTupleHTupleHtuple (real / integer) (double / int / long) (double / Hlong) (double / Hlong)

Input pixel(s) (column coordinate).

Default value: 64

Suggested values: 0, 16, 32, 64, 128, 256, 512, 1024

RowTransRowTransRowTransRowTransrowTrans (output_control)  point.x(-array) → HTupleHTupleHtuple (real) (double) (double) (double)

Output pixel(s) (row coordinate).

ColTransColTransColTransColTranscolTrans (output_control)  point.y(-array) → HTupleHTupleHtuple (real) (double) (double) (double)

Output pixel(s) (column coordinate).

Result

If the matrix HomMat2DHomMat2DHomMat2DHomMat2DhomMat2D represents an affine transformation (i.e., not a projective transformation), affine_trans_pixelaffine_trans_pixelAffineTransPixelAffineTransPixelAffineTransPixel returns 2 (H_MSG_TRUE). Otherwise, an exception is raised.

Possible Predecessors

hom_mat2d_translatehom_mat2d_translateHomMat2dTranslateHomMat2dTranslateHomMat2dTranslate, hom_mat2d_translate_localhom_mat2d_translate_localHomMat2dTranslateLocalHomMat2dTranslateLocalHomMat2dTranslateLocal, hom_mat2d_scalehom_mat2d_scaleHomMat2dScaleHomMat2dScaleHomMat2dScale, hom_mat2d_scale_localhom_mat2d_scale_localHomMat2dScaleLocalHomMat2dScaleLocalHomMat2dScaleLocal, hom_mat2d_rotatehom_mat2d_rotateHomMat2dRotateHomMat2dRotateHomMat2dRotate, hom_mat2d_rotate_localhom_mat2d_rotate_localHomMat2dRotateLocalHomMat2dRotateLocalHomMat2dRotateLocal, hom_mat2d_slanthom_mat2d_slantHomMat2dSlantHomMat2dSlantHomMat2dSlant, hom_mat2d_slant_localhom_mat2d_slant_localHomMat2dSlantLocalHomMat2dSlantLocalHomMat2dSlantLocal, hom_mat2d_reflecthom_mat2d_reflectHomMat2dReflectHomMat2dReflectHomMat2dReflect, hom_mat2d_reflect_localhom_mat2d_reflect_localHomMat2dReflectLocalHomMat2dReflectLocalHomMat2dReflectLocal

Alternatives

affine_trans_point_2daffine_trans_point_2dAffineTransPoint2dAffineTransPoint2dAffineTransPoint2d

Module

Foundation

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HALCON Operator Reference 19.11.0.0 Copyright © 1996-2019 MVTec Software GmbH