transformPointsInverse

应用反向几何变换

Syntax

[u，v] = transformpointsinverse（tform，x，y）

[u,v,w] = transformPointsInverse(tform,x,y,z)

U = transformPointsInverse(tform,X)

描述

[u,v] = transformpointsinverse（tform,x,y)应用的逆变换2-D geometric transformationtformto the points specified by coordinatesx和y.

[u,v,w] = transformpointsinverse（tform,x,y,z)应用3-D几何变换的反变tformto the points specified by coordinatesx,y，和z.

U= transformpointsinverse（tform,X)应用的逆变换tformto the input coordinate matrixX和returns the coordinate matrixU.transformPointsInversemaps thekth pointX(k，:)U(k,:).

例子

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应用二维几何变换的反变

Create anaffine2dobject that defines the transformation.

theta = 10;tform = extine2d（[[cosd（theta）-sind（theta）0; sind（theta）cosd（theta）0; 0 0 1]）

tform= affine2d with properties: T: [3x3 double] Dimensionality: 2

将2D几何转换的正向转换应用于输入点。

[x，y] = transformpointsforward（tform，5,10）

X = 6.6605 Y = 8.9798

Apply inverse transformation of 2-D geometric transformation to output point from the previous step to recover the original coordinates.

[U,V] = transformPointsInverse(tform,X,Y)

U = 5.0000 V = 10

Transform Packed Coordinates Using Custom 2-D Transformation

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Specify the packed (x,y) coordinates of five input points. The packed coordinates are stored in a 5-by-2 matrix, where thex-coordinate of each point is in the first column, and they-coordinate of each point is in the second column.

XY = [10 15;11 32;15 34;2 7;2 10];

Define the inverse mapping function. The function accepts and returns points in packed (x,y) format.

inversefn =@(c) [c(:,1)+c(:,2),c(:,1)-c(:,2)]

inversefn =function_handle with value:@(c)[c(:,1)+c(:,2),c(:,1)-c(:,2)]

创建一个二维几何变换对象，tform，存储逆映射函数。

tform =几何图transform2d（inverseFN）

tform= geometricTransform2d with properties: InverseFcn: @(c)[c(:,1)+c(:,2),c(:,1)-c(:,2)] ForwardFcn: [] Dimensionality: 2

Apply the inverse geometric transform to the input points.

UV = transformPointsInverse(tform,XY)

UV =5×225 -5 43 -21 49 -19 9 -5 12 -8

应用3-D几何变换的反向转换

Create anaffine3dobject that defines the transformation.

tform= affine3d([3 1 2 0;4 5 8 0;6 2 1 0;0 0 0 1])

tform= affine3d with properties: T: [4×4 double] Dimensionality: 3

应用向前变换of 3-D geometric transformation to an input point.

[X,Y,Z] = transformPointsForward(tform,2,3,5)

X = 48 Y = 27 Z = 33

Apply inverse transformation of 3-D geometric transformation to output point from the previous step to recover the original coordinates.

[U,V,W] = transformPointsInverse(tform,X,Y,Z)

U = 2.0000 V = 3 W = 5.0000

Transform Packed Coordinates Using Custom 3-D Transformation

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Specify the packed (x,y,z) coordinates of five input points. The packed coordinates are stored as a 5-by-3 matrix, where the first, second, and third columns contain thex- ，，y- ，，和z-坐标分别。

XYZ = [5 25 20;10 5 25;15 10 5;20 15 10;25 20 15];

定义一个接收并返回包装中点的逆映射函数（x,y,z) format.

inverseFcn = @（c）[c（：1）+c（：，2），c（：，1）-c（：，2），c（：，3）。^2];

Create a 3-D geometric transformation object,tform，该存储此逆映射函数。

tform = geometrictransform3d（inverseFCN）

tform =具有属性的deemogetrictransform3d：inversefcn： @（c）[c（：：，1）+c（：，2），c（：，1）-c（：，2），c（：，3）。^2] forwardfcn：[]维度：3

将此3-D几何转换的反变形应用于输入点。

uvw = transformpointsinverse（tform，xyz）

UVW =5×330 -20 400 15 5 625 25 5 25 35 5 100 45 5 225

Input Arguments

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`tform`—几何变换
几何转换对象

几何变换，指定为几何变换对象。

对于二维几何变换，tformcan be arigid2d,affine2d,Projective2d,几何图2D,LocalWeightedMeanTransformation2D,PiecewiseLinearTransformation2D, orpolyenmialtransformation2d几何转换对象。

对于3D几何变换，tform可以是一个affine3d,rigid3d, or几何图形3D几何转换对象。

`x`—x-coordinates of points to be transformed
m-经过-n或者m-经过-n-经过-pnumeric array

x-coordinates of points to be transformed, specified as anm-经过-n或者m-经过-n-经过-p数字阵列。尺寸的数量xmatches the dimensionality oftform.