常见几何变换

使用 imwarp 工作流执行常见几何变换

几何变换将输出图像中的像素坐标映射到输入图像中的坐标。然后，映射过程根据输入图像对输出像素进行插值。

使用这些函数可执行一般的二维、三维和 N 维几何变换。要执行二维或三维几何变换，请首先创建一个几何变换对象，用来存储变换信息。然后，将要变换的图像和几何变换对象传递给 imwarp 函数。

函数

创建二维和三维几何变换

`fitgeotform2d`	根据控制点对组进行二维几何变换拟合 (自 R2022b 起)
`affinetform2d`	二维仿射几何变换 (自 R2022b 起)
`affinetform3d`	3-D affine geometric transformation (自 R2022b 起)
`rigidtform2d`	2-D rigid geometric transformation (自 R2022b 起)
`rigidtform3d`	3-D rigid geometric transformation (自 R2022b 起)
`simtform2d`	2-D similarity geometric transformation (自 R2022b 起)
`simtform3d`	3-D similarity geometric transformation (自 R2022b 起)
`transltform2d`	2-D translation geometric transformation (自 R2022b 起)
`transltform3d`	3-D translation geometric transformation (自 R2022b 起)
`projtform2d`	2-D projective geometric transformation (自 R2022b 起)
`geometricTransform2d`	2-D geometric transformation object
`geometricTransform3d`	3-D geometric transformation object
`PiecewiseLinearTransformation2D`	2-D piecewise linear geometric transformation
`PolynomialTransformation2D`	2-D polynomial geometric transformation
`LocalWeightedMeanTransformation2D`	2-D local weighted mean geometric transformation

应用二维和三维几何变换

`imwarp`	对图像应用几何变换
`transformPointsForward`	Apply forward geometric transformation
`transformPointsInverse`	Apply inverse geometric transformation
`Warper`	Apply same geometric transformation to many images efficiently

创建和应用 N 维空间变换

`tformarray`	Apply spatial transformation to N-D array
`findbounds`	Find output bounds for spatial transformation
`fliptform`	Flip input and output roles of spatial transformation structure
`makeresampler`	Create resampling structure
`maketform`	Create N-D spatial transformation structure (`TFORM`)
`tformfwd`	Apply forward N-D spatial transformation
`tforminv`	Apply inverse N-D spatial transformation

定义坐标系之间的空间参照

`imref2d`	Reference 2-D image to world coordinates
`imref3d`	Reference 3-D image to world coordinates
`affineOutputView`	Create output view for warping images

主题

几何变换

2-D and 3-D Geometric Transformation Process Overview
To perform a general geometric transformation of a 2-D or 3-D image, first define the parameters of the transformation, then warp the image.
几何变换的矩阵表示
使用矩阵表示几何变换，如平移、缩放、旋转和翻转，矩阵的元素表示变换的参数。
Migrate Geometric Transformations to Premultiply Convention
Starting in R2022b, functions that create and perform geometric transformations were updated to use a premultiply matrix convention.
N-Dimensional Spatial Transformations
You can create custom geometric transformations to process images of arbitrary dimension, or to change the dimensionality of the output image from the input image.
Specify Fill Values in Geometric Transformation Output
Specify the color of blank space in the image after a geometric transformation.

空间参照

图像坐标系
了解如何使用离散像素索引和连续空间坐标来表示图像位置。
Define World Coordinate System of Image
Spatial referencing objects encode the relationship between the image extent in intrinsic coordinates, the image extent in world coordinates, and the image resolution.
平移所显示图像的 X 和 Y 坐标范围
此示例说明如何通过更改所显示图像的 XData 和 YData 属性来指定非默认世界坐标系。

精选示例

Create Composite 2-D Affine Transformations

Combine multiple affine geometric transformations using matrix multiplication.

打开实时脚本

Create a Gallery of Transformed Images

Warp a test image using several built-in and custom geometric transformations, including affine, projective, polynomial, piecewise linear, sinusoidal, barrel, and pin-cushion transformations.

打开实时脚本

Perform Simple 2-D Translation Transformation

Shift an image vertically and horizontally, and use spatial referencing information to display the original image and the translated image from the same perspective.