Source code for
vl_demo_sift_peak.m
This file is located in the toolbox/demo folder in VLFeat package.
% VL_DEMO_SIFT_PEAK Demo: SIFT: peak treshold
randn('state',0) ;
rand('state',0) ;
I = double(rand(100,500) <= .005) ;
I = (ones(100,1) * linspace(0,1,500)) .* I ;
I(:,1) = 0 ; I(:,end) = 0 ;
I(1,:) = 0 ; I(end,:) = 0 ;
I = 2*pi*4^2 * vl_imsmooth(I,4) ;
I = single(255 * I) ;
figure(1) ; clf ;
imagesc(I) ; colormap gray ;
axis equal ; axis off; axis tight ;
hold on ;
vl_demo_print('sift_peak_0') ;
tpr = [0 10 20 30] ;
for tp=tpr
f = vl_sift(I, ...
'PeakThresh', tp, ...
'EdgeThresh', 10000, ...
'FirstOctave', -1) ;
h1 = vl_plotframe(f) ;
set(h1,'color','k','linewidth',3) ;
h2 = vl_plotframe(f) ;
set(h2,'color','y','linewidth',2) ;
vl_demo_print(sprintf('sift_peak_%d',find(tp==tpr))) ;
delete(h1) ;
delete(h2) ;
end