用SIFT特征和RANSAC算法进行两幅图片的匹配

大家知道相机可以做到将几个不同场景的图片匹配形成一幅图，此处用sift特征与ransac算法相结合的方法来进行图像的匹配。

详细过程见程序如下：（运行前装库文件vlfeat）

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%两幅图的匹配

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function mosaic = sift_mosaic(im1, im2)

if nargin == 0
  im1 = imread(fullfile(vl_root, 'data', '图片1.jpg')) ;
  im2 = imread(fullfile(vl_root, 'data', '图片2.jpg')) ;
end

% make single
im1 = im2single(im1) ;
im2 = im2single(im2) ;

% make grayscale
if size(im1,3) > 1, im1g = rgb2gray(im1) ; else im1g = im1 ; end
if size(im2,3) > 1, im2g = rgb2gray(im2) ; else im2g = im2 ; end

% --------------------------------------------------------------------
%              &n