Main Content

length

Number of stored points

Description

example

length(points) returns the number of stored points in the points object.

Examples

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Read an image.

I = imread("cameraman.tif");

Detect KAZE points from the image.

points = detectKAZEFeatures(I);

Find number of stored points.

numPoints = length(points)
numPoints = 631

Extract KAZE features from the detected points.

[features,validPoints] = extractFeatures(I,points);

Plot the ten strongest valid extracted points and show their orientations.

imshow(I)
hold on
strongestPoints = selectStrongest(validPoints,10);
plot(strongestPoints,showOrientation=true)
hold off

Figure contains an axes object. The axes object contains 3 objects of type image, line.

Input Arguments

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Points object,specified as an M-by-2 matrix of M number of [x y] coordinates, or as one of the point feature objects described in Point Feature Types. The object contains information about the feature points detected in the input image. To obtain points, use the appropriate detect function that pairs with the point feature type.

Version History

Introduced in R2017b