Moravec检测角点,给出matlab代码。

Moravec角点检测是一种计算机视觉算法，用于检测图像中的角点。下面是一段MATLAB代码实现：

function [cim, r, c] = Moravec(im, w, threshold)
% MORAVEC Corner Detector.
%   [CIM, R, C] = MORAVEC(IM, W, THRESHOLD) detects corners in image IM
%   using the Moravec corner detector. W is the window size used for
%   feature extraction (typically W=3 or 5). THRESHOLD is a threshold 
%   value between 0 and 1 used to suppress weak corners. CIM is a binary
%   image marking the corner locations. R and C are column vectors 
%   containing the row and column coordinates of the detected corners.
%
%   Example:
%       im = imread('cameraman.tif');
%       [cim, r, c] = Moravec(im, 3, 0.2);
%       figure; imshow(im); hold on; plot(c,r,'ys'); hold off;
%
%   See also: harris, corner, detectHarrisFeatures, detectMinEigenFeatures,
%             detectFASTFeatures, detectSURFFeatures, detectMSERFeatures,
%             detectBRISKFeatures, detectORBFeatures, detectHOGFeatures,
%             extractHOGFeatures, matchFeatures, estimateGeometricTransform,
%             imregister, vision.PointTracker.

    % Check input arguments
    error(nargchk(2, 3, nargin));
    if nargin < 3
        threshold = 0.1;
    end

    % Compute second moments
    Ix = conv2(im, [-1 0 1], 'same');
    Iy = conv2(im, [-1; 0; 1], 'same');
    Ixx = Ix .^ 2;
    Iyy = Iy .^ 2;
    Ixy = Ix .* Iy;

    % Compute corner response
    cim = zeros(size(im));
    r = [];
    c = [];
    offset = floor(w / 2);
    for i = offset+1:size(im,1)-offset
        for j = offset+1:size(im,2)-offset
            Sxx = sum(sum(Ixx(i-offset:i+offset,j-offset:j+offset)));
            Syy = sum(sum(Iyy(i-offset:i+offset,j-offset:j+offset)));
            Sxy = sum(sum(Ixy(i-offset:i+offset,j-offset:j+offset)));
            cim(i,j) = min(Sxx,Syy);
            if cim(i,j) > threshold * max(cim(i-offset:i+offset,j-offset:j+offset), [], 'all')
                r = [r; i];
                c = [c; j];
            end
        end
    end

end

该算法首先计算图像的二阶矩矩阵，然后计算每个像素点的角点响应值。最后，使用阈值将弱角点抑制掉，输出结果为二进制图像（标记角点位置）和角点坐标。