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detectMinEigenFeatures

Detect corners using minimum eigenvalue algorithm

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Syntax

points = detectMinEigenFeatures(I)
points = detectMinEigenFeatures(I,Name,Value)

Description

points = detectMinEigenFeatures(I) returns a cornerPoints object points that contains information about corner features detected in the 2-D grayscale or binary input using the minimum eigenvalue algorithm developed by Shi and Tomasi.

example

points = detectMinEigenFeatures(I,Name,Value) uses additional options specified by one or more name-value arguments.

Examples

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Open Live Script

Read the image.

I = checkerboard;

Find the corners.

corners = detectMinEigenFeatures(I);

Display the results.

imshow(I); hold on;
plot(corners.selectStrongest(50));

Figure contains an axes object. The hidden axes object contains 2 objects of type image, line. One or more of the lines displays its values using only markers

Input Arguments

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Input image, specified as an M-by-N 2-D grayscale or binary image. The input image must be real and nonsparse.

Data Types: single | double | int16 | uint8 | uint16 | logical

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'MinQuality','0.01','ROI', [50,150,100,200] specifies that the detector must use a 1% minimum accepted quality of corners within the designated region of interest. This region of interest is located at x=50, y=150. The ROI has a width of 100 pixels, and a height of 200 pixels.

Minimum accepted quality of corners, specified as the comma-separated pair consisting of 'MinQuality' and a scalar value in the range [0,1].

The minimum accepted quality of corners represents a fraction of the maximum corner metric value in the image. Larger values can be used to remove erroneous corners.

Example: 'MinQuality', 0.01

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Gaussian filter dimension, specified as the comma-separated pair consisting of 'FilterSize' and an odd integer value in the range [3, inf).

The Gaussian filter smooths the gradient of the input image.

The function uses the FilterSize value to calculate the filter’s dimensions, FilterSize-by-FilterSize. It also defines the standard deviation as FilterSize/3.

Example: 'FilterSize', 5

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Rectangular region for corner detection, specified as a comma-separated pair consisting of 'ROI' and a vector of the format [x y width height]. The first two integer values [x y] represent the location of the upper-left corner of the region of interest. The last two integer values represent the width and height.

Example: 'ROI', [50,150,100,200]

Output Arguments

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Corner points, returned as a cornerPoints object. The object contains information about the point features detected in the 2-D grayscale or binary input image.

References

[1] Shi, J., and C. Tomasi, "Good Features to Track," Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition, June 1994, pp. 593–600.

Extended Capabilities

Version History

Introduced in R2013a

See Also

Functions

Objects

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