Samples of Key Points and Descriptors

We tried these codes in order to find key points and descriptors. Then we have these pictures as results of changing the bold line with the ones above each pictures.

imPath = fullfile(‘alex.jpg’) ;
im = imread(imPath) ;
imgs = im2single(rgb2gray(im)) ;
[frames, descrs] = vl_sift(imgs) ;
imagesc(im) ; colormap gray; hold on ;
vl_plotframe(frames) ;
vl_plotsiftdescriptor(descrs(:,432), frames(:,432)) ;

original image:

[frames, descrs] = vl_sift(imgs) ;

frames = vl_covdet(imgs, 'verbose') ;

frames = vl_covdet(imgs, 'method', 'Hessian') ;

frames = vl_covdet(imgs, 'method', 'HarrisLaplace');

frames = vl_covdet(imgs, 'EstimateAffineShape', true) ;