主要内容

检测器

Detect ORB keypoints and return anOrbpointsobject

collapse all in page

Syntax

点= detectorBfeatures（I)
点= detectorBfeatures（i，名称，值）

Description

example

点= detectorBfeatures（I)返回Orbpointsobject that contains information about ORB keypoints. The ORB keypoints are detected from the input image by using the Oriented FAST and rotated BRIEF (ORB) feature detection method.

example

点= detectorBfeatures（I,Name,Value)使用一个或多个名称值对参数指定选项。

Examples

collapse all

打开实时脚本

在工作区中阅读图像。

I = imread('BusinessCard.png');

将图像转换为灰度图像。

I = im2gray(I);

Display the grayscale image.

figure imshow(I)

Figure contains an axes object. The axes object contains an object of type image.

检测并存储球体关键点。

点= detectorBfeatures（i）;

显示灰度图像，并绘制检测到的ORB关键点。抑制围绕检测到的关键点的圆的显示。在具有高强度差异的区域中检测到ORB关键点。

figure imshow(I) hold上plot(points,'ShowScale',false) hold离开

Figure contains an axes object. The axes object contains 2 objects of type image, line.

打开实时脚本

Read a binary image into the workspace.

I = imread('star.png');

显示图像。

figure imshow(I)

Figure contains an axes object. The axes object contains an object of type image.

检测并存储球体关键点。Specify the scale factor for image decomposition as 1.01 and the number of decomposition levels as 3.

点= detectorBfeatures（I,'ScaleFactor'，1.01，'NumLevels',3);

显示图像并绘制检测到的Orb关键点。检测到二进制形状图像中的拐点为ORB关键点。

figure imshow(I) hold上情节（点）保持离开

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

Input Arguments

collapse all

输入图像，指定为M-经过-Ngrayscale image. The input image must be real and nonsparse.

Data Types:single|double|INT16|uint8|UINT16|日志ical

Name-Value Arguments

将可选的参数对Name1=Value1,...,NameN=ValueN, whereNameis the argument name and价值是相应的值。名称值参数必须在其他参数之后出现，但是对的顺序并不重要。

Before R2021a, use commas to separate each name and value, and encloseNamein quotes.

例子：detectorBfeatures（i，'numlevels'，4）

图像分解的比例因子, specified as the comma-separated pair consisting of'ScaleFactor'and a scalar greater than 1. The scale value at each level of decomposition isScaleFactor(等级-1), where等级is any value in the range [0,Numlevels-1]. Given the input image of sizeM-经过-N，每个分解级别的图像大小为 M S c a l e F a c t o r ( l e v e l − 1 ) -经过- N S c a l e F a c t o r ( l e v e l − 1 ) .

Data Types:single|double|int8|INT16|INT32|int64|uint8|UINT16|uint64|uint32

分解水平的数量, specified as the comma-separated pair consisting of'NumLevels'and a scalar greater than or equal to 1. Increase this value to extract keypoints from the image at more levels of decomposition.

The number of decomposition levels for extracting keypoints is limited by the image size at that level. The image size at a level of decomposition must be at least 63-by-63 for detecting keypoints. The maximum level of decomposition is calculated as

l e v e l 最大限度 = floor ( 日志 ( min ( M , N ) ) − 日志 ( 63 ) 日志 ( ScaleFactor ) ) + 1

If either the default value or the specified value of'NumLevels'大于等级最大限度，该功能修改NumLevelsto等级最大限度and returns a warning.

Data Types:single|double|int8|INT16|INT32|int64|uint8|UINT16|uint64|uint32

感兴趣的地区for keypoint detection, specified as the comma-separated pair consisting of'ROI'和格式的向量[xy宽度height]. The first two elements represent the location of the upper left corner of the region of interest. The last two elements represent the width and the height of the region of interest. The width and height of the region of interest must each be a value greater than or equal to 63.

Output Arguments

collapse all

Orb KeyPoints，返回Orbpoints目的。该对象包含有关输入图像中检测到的关键点的信息。

算法

The function detects keypoints from the input image by using the ORB feature detection method in[1].

参考

[1]Rublee, E., V. Rabaud, K. Konolige, and G. Bradski. "ORB: An Efficient Alternative to SIFT or SURF." In2011年国际计算机视觉会议论文集, 2564–2571. Barcelona, Spain: IEEE, 2011.

Extended Capabilities

C/C++ Code Generation
使用MATLAB®CODER™生成C和C ++代码。

Version History

Introduced in R2019a

See Also

|||||||||

Topics