orb算法的matlab实现

ORB（Oriented FAST and Rotated BRIEF）算法是一种计算机视觉算法，用于在图像中检测关键点和描述符。下面是ORB算法的Matlab实现：

1. 首先，使用Matlab中的SURF函数检测关键点和描述符：

% Load image
img = imread('test.jpg');

% Convert to grayscale
gray = rgb2gray(img);

% Detect keypoints and descriptors using SURF
points = detectSURFFeatures(gray);
[features, points] = extractFeatures(gray, points);

2. 然后使用Matlab中的ORB函数对描述符进行旋转和匹配：

% Create ORB object
orb = cv.ORB();

% Set parameters
orb.MaxFeatures = 500;
orb.ScaleFactor = 1.2;
orb.NLevels = 8;
orb.EdgeThreshold = 31;
orb.FirstLevel = 0;
orb.WTA_K = 2;
orb.ScoreType = 'Harris';
orb.PatchSize = 31;

% Compute descriptors
features = orb.compute(gray, points);

% Match descriptors
indexPairs = matchFeatures(features1,features2);
matchedPoints1 = points1(indexPairs(:,1),:);
matchedPoints2 = points2(indexPairs(:,2),:);

此处的描述符匹配使用的是基于汉明距离的特征匹配。