Halon common affine transformation operators

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halcon Common affine transformation operators _Strauss Lupusson The blog of -CSDN Blog _halcon Affine transformation operator

Affine transformation

Affine transformation mainly includes translation transformation 、 Rotation transformation 、 Zoom transform （ It's also called scaling ）、 Tilt shift （ It's also called stagger transformation 、 Shear transform 、 Offset transformation ）、 Flip transformation . There are six degrees of freedom .

To perform an affine transformation , You must get the transform first matrix . To get the transformation matrix , The coordinates of feature points must be obtained first 、 Angle and other information , Geometric matching and bolb It is an efficient method to obtain feature points , There are other ways , As long as the characteristic points can be obtained stably .

Affine transformation process

（1.） Obtain the coordinates of feature points 、 angle

（2.） Calculate the affine transformation matrix

（3.） To image 、 Area 、 Affine transformation of contour

According to feature points 、 Angle calculation affine transformation matrix

hom_mat2d_identity(:::HomMat2DIdentity)

function ： Generate affine transformation matrix

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hom_mat2d_rotate(::HomMat2D,Phi,Px,Py:HomMat2DRotate)

function ： Add the rotation angle to the affine transformation matrix

HomMat2D：（ Input parameters ） Affine transformation matrix

Phi（ Input parameters ）： Rotation Angle （ Unit radian ）

Px（ Input parameters ）： Transformed fixed point row coordinates . A fixed point is an affine transformation supported by this point （ Here it means to rotate around this point ）

Py:（ Input parameters ） Fixed point column coordinates of transformation

HomMat2DRotate：（ Output parameters ） Output transformation matrix

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hom_mat2d_scale(::HomMat2D,Sx,Sy,Px,Py:HomMat2DScale)

function ： Add scaling to the affine transformation matrix

HomMat2D（ Input parameters ）： Affine transformation matrix

Sx（ Input parameters ）：x Scaling factor in the axis direction

Sy（ Input parameters ）：y Scaling factor in the axis direction

Px（ Input parameters ）： Transformed fixed point row coordinates

Py（ Input parameters ）: Fixed point column coordinates of transformation

HomMat2DScale（ Output parameters ）： Output transformation matrix

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hom_mat2d_translate(::HomMat2D,Tx,Ty:HomMat2DTranslate)

function ： Add translation to the anti fire transformation matrix

HomMat2D：（ Input parameters ） Affine transformation matrix

Tx（ Input parameters ）： Along the x The distance of translation in the axis direction

Ty: Input parameters ）： Along the y The distance of translation in the axis direction

HomMat2DTranslate( Output parameters )： Output transformation matrix

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hom_mat2d_slant(::HomMat2D,Theta,Axis,Px,Py:HomMat2DSlant)

function ： Add the oblique tangent to the anti fire transformation matrix

HomMat2D( Input parameters ): Affine transformation matrix

Theta( Input parameters ): Bevel angle （ Company ： radian ）

Axis( Input parameters ): The axis of the oblique cut . Value list ：x,y

Px( Input parameters ): Fixed point of transformation x coordinate

Py( Input parameters ): Fixed point of transformation y coordinate

HomMat2DSlant( Output parameters ): Output affine transformation matrix

vector_angle_to_rigid(::Row1,Column1,Angle1,Row2,Column2,Angle2:HomMat2D)

function ： The rigid affine transformation matrix is calculated according to the point and angle , Support rotation and translation

Row1( Input parameters ): Original point line coordinates

Column1( Input parameters ): Original point column coordinates

Angle1( Input parameters ): Original point angle

Row2( Input parameters ): The destination line coordinates of the transformation

Column2( Input parameters ): The coordinates of the destination column of the transformation

Angle2( Input parameters ): The destination angle of the transformation

HomMat2D( Output parameters ): Output affine transformation matrix

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The affine transformation matrix is calculated according to more than two characteristic points

vector_to_rigid(::Px,Py,Qx,Qy：HomMat2D)

function ： The rigid affine transformation matrix is calculated according to more than two point pairs , Support rotation and translation

Px:( Input parameters ) Of the original point group x coordinate

Py:( Input parameters ) Of the original point group y coordinate

Qx:( Input parameters ) The destination group of the transformation x coordinate

Qy:( Input parameters ) The destination group of the transformation y coordinate

HomMat2D:( Output parameters ) Output affine transformation matrix

vector_to_similarity(::Px,Py,Qx,Qy：HomMat2D)

function ： Calculate the similar affine transformation matrix according to more than two point pairs , Support rotation 、 Pan and zoom

Px:( Input parameters ) Of the original point group x coordinate

Py:( Input parameters ) Of the original point group y coordinate

Qx:( Input parameters ) The destination group of the transformation x coordinate

Qy:( Input parameters ) The destination group of the transformation y coordinate

HomMat2D:( Output parameters ) Output affine transformation matrix

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The affine transformation matrix is obtained according to more than three feature points

vector_to_hom_mat2d(::Px,Py,Qx,Qy：HomMat2D)

function ： Calculate the affine transformation matrix according to more than three point pairs , Support rotation 、 translation 、 The zoom 、 Oblique cutting

Px:( Input parameters ) Of the original point group x coordinate

Py:( Input parameters ) Of the original point group y coordinate

Qx:( Input parameters ) The destination group of the transformation x coordinate

Qy:( Input parameters ) The destination group of the transformation y coordinate

HomMat2D:( Output parameters ) Output affine transformation matrix

Calculate affine transformation parameters

hom_mat2d_to_affine_par(::HomMat2D：Sx,Sy,Phi,Theta,Tx,Ty)

function ： According to the affine transformation matrix （ Homogeneous two-dimensional transformation matrix ） Calculate affine transformation parameters

HomMat2D( Input parameters ): Affine transformation matrix

Sx( Output parameters ):x The scaling factor of the direction （ If you change from image space to physical space , Namely x The direction of the Single pixel quantity ）

Sy( Output parameters ):y The scaling factor of the direction （ If you change from image space to physical space , Namely y The direction of the Single pixel quantity ）

Phi( Output parameters ): Rotation Angle

Theta( Output parameters ): Bevel angle

Tx( Output parameters ): Along the x Direction translation distance

Ty( Output parameters ): Along the y Direction translation distance

8. To image 、ROI and XLD Affine transformation

affine_trans_contour_xld(Contours:ContoursAffinTrans:HomMat2D)

function ： Yes XLD Two dimensional affine transformation of contour , Support zoom , rotate , translation , Oblique cutting

Contours( Input parameters ): Input XLD outline

ContoursAffinTrans( Output parameters ): Output transformed XLD outline

HomMat2D( Input parameters )： Affine transformation matrix

affine_trans_image(Image:ImageAffinTrans:HomMat2D,Interpolation,AdaptImageSize)

function ： Carry out two-dimensional affine transformation on the image contour , Support zoom 、 rotate 、 translation , Oblique cutting

Image( Input parameters ): The input image

ImageAffinTrans( Output parameters ): The transformed image

HomMat2D( Input parameters )： Affine transformation matrix

Interpolation( Input parameters )： Interpolation algorithm . Parameter value list ： nearest_neighbor,bilinear,constant,weighted

AdaptImageSize( Input parameters )： Results whether the image size is adaptive . The default value is ：false

affine_trans_region(Region:RegionAffineTrans:HomMat2D,Interpolate:)

function ： Perform arbitrary two-dimensional affine transformation on the region

Region( Input parameters ): Input area

RegionAffineTrans( Output parameters ): Transformed region

HomMat2D( Input parameters )： Affine transformation matrix

Interpolate( Input parameters ): Interpolation algorithm . The default value is ：nearest_neighbor. Parameter value list ：constant,nearest_neighbor

affine_trans_polygon_xld(Polygon:PolygonsAffinTrans:HomMat2D:)

function ： Yes XLD Arbitrary two-dimensional affine transformation of polygons

Polygon( Input parameters ): Input XLD polygon

PolygonsAffinTrans( Output parameters ): Transformed XLD polygon

HomMat2D( Input parameters ): Affine transformation matrix

affine_trans_point_2d(::HomMat2D,Px,Py:Qx,Qy)

function ： Arbitrary two-dimensional affine transformation of points , Support zoom 、 rotate 、 translation 、 Oblique cutting

HomMat2D( Input parameters ): Affine transformation matrix

Px( Input parameters ): Original point x Or row coordinates

Py( Input parameters ): Original point y Or column coordinates

Qx( Output parameters ): Transformation point x Or row coordinates

Qy( Output parameters ): Transformation point y Or column coordinates

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

function ： Arbitrary two-dimensional affine transformation of pixels

HomMat2D( Input parameters ): Affine transformation matrix

Row( Input parameters ): Enter pixel row coordinates

Col( Input parameters ): Enter the pixel column coordinates

RowTrans( Output parameters ): Transformed pixel row coordinates

ColTrans( Output parameters ): Transformed pixel column coordinates

ps：affine_trans_point_2d And affine_trans_pixel The difference between ：affine_trans_pixel The origin of the image coordinate system used is in the upper left corner of the image ,affine_trans_point_2d Use the standard image coordinate system , The origin is at the center of the pixel in the upper left corner