# isEpipoleInImage

Determine whether image contains epipole

## Syntax

``isIn = isEpipoleInImage(F,imageSize)``
``isIn = isEpipoleInImage(F',imageSize)``
``````[isIn,epipole] = isEpipoleInImage(___)``````

## Description

````isIn = isEpipoleInImage(F,imageSize)` determines whether the first stereo image associated with the fundamental matrix `F` contains an epipole. `imageSize` is the size of the first image, and is in the format returned by the function `size`.```
````isIn = isEpipoleInImage(F',imageSize)` determines whether the second stereo image associated with the fundamental matrix `F`' contains an epipole.```
``````[isIn,epipole] = isEpipoleInImage(___)``` also returns the epipole. ```

## Examples

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```% Load stereo point pairs. load stereoPointPairs f = estimateFundamentalMatrix(matchedPoints1, matchedPoints2, 'NumTrials', 2000); imageSize = [200 300]; % Determine whether the image contains epipole and epipole location. [isIn,epipole] = isEpipoleInImage(f,imageSize)```
```isIn = logical 1 ```
```epipole = 1×2 256.5465 100.0140 ```

## Input Arguments

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Fundamental matrix, specified as a 3-by-3 matrix computed from stereo images. `F` must be double or single. If P1 represents a point in the first image I1 that corresponds to P2, a point in the second image I2, then:

 [P2,1] * `F` * [P1,1]’ = 0

In computer vision, the fundamental matrix is a 3-by-3 matrix which relates corresponding points in stereo images. When two cameras view a 3-D scene from two distinct positions, there are a number of geometric relations between the 3-D points and their projections onto the 2-D images that lead to constraints between the image points. Two images of the same scene are related by epipolar geometry.

Image size, specified in the format returned by the `size` function.

## Output Arguments

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Valid epipole logical, specified as `true` when the image contains an epipole, and `false` when the image does not contain an epipole.

When the image planes are at a great enough angle to each other, you can expect the epipole to be located in the image. When the image planes are at a more subtle angle to each other, you can expect the epipole to be located outside of the image, (but still in the image plane). Location of epipole, returned as a 1-by-2 vector.