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AVL.ImagePolarTransform

Transforms an image to polar or log-polar space.

Namespace:AvlNet
Assembly:AVL.NET.dll

Syntax

C++
C#
 
public static void ImagePolarTransform
(
	AvlNet.Image inImage,
	AvlNet.Point2D inCenter,
	AvlNet.PolarSpaceType inOutputSpaceType,
	AvlNet.PolarInterpolationMethod inInterpolation,
	AvlNet.Image outImage
)

Parameters

Name Type Range Default Description
inImageAvlNet.ImageInput image.
inCenterAvlNet.Point2DCenter of the coordinate system in input image.
inOutputSpaceTypeAvlNet.PolarSpaceTypeMethod of transformation.
inInterpolationAvlNet.PolarInterpolationMethodMethod of underlying interpolation.
outImageAvlNet.ImageOutput image.

Description

It uses the following transformation:

\[ dst(\rho, \phi) = src(x,y), \]

where

\[ \rho = m \sqrt{x^2 + y^2} , \phi = \arctan(\frac{y}{x}), \]

for linear-polar space, and

\[ \rho = k \log{\sqrt{x^2+y^2} }, \phi = \arctan(\frac{y}{x}), \]

for log-polar space, which emulates the human "foveal vision".

Parameters \(m\) and \(k\) are chosen so that entire source image could fit into output image.

Transformation does not change image dimensions.

Examples

ImagePolarTransform performed on the sample image with inCenter = (150,150), and inOutputSpaceType Polar and LogPolar respectively.

See also