user1222309

 Jul 14 awarded Popular Question May 11 comment Can SIFT algorithm extract feature in real-time speed on PC?@drhirsch haha, ok, let me give it a speicific definition. Running on a standard PC means running on CPU only. May 11 awarded Commentator May 11 comment Can SIFT algorithm extract feature in real-time speed on PC?@Pablo, I do not aim to accelerate the algorithm, I just want to compare the speed of several algorithm on PC. So I need to know the real speed of SIFT on a PC(not on other hardware). May 11 revised Can SIFT algorithm extract feature in real-time speed on PC?deleted 9 characters in body May 11 comment Can SIFT algorithm extract feature in real-time speed on PC?@Jerry Coffin sorry, it's 3000, not 3000 thousand^_^ May 11 asked Can SIFT algorithm extract feature in real-time speed on PC? May 9 comment How does Lowe compute the “repeatability” of his SIFT Algorithm?that (12,45) of the first image is the same location of (67,24) of the second image, so I can say they are in the same location. However what about the 1.9 and 2.8? I can't say 2.8>1.9*sqrt(2), so they are not the same scale, Afterall, they are in different images. What's your opinion? May 9 comment How does Lowe compute the “repeatability” of his SIFT Algorithm?So basicly whether a keypoint is repeatably detected is defined by its location and scale. The location should be within σ pixels in the x and y directions, and the scale should be within a factor of sqrt(2) of the correct scale. I can tell if a location is right by check whether the keypoint appears in same position of two images, if so, the keypoint pair match. However, how can I know whether the scale of the keypoint pair still match? For example, a keypoint has location (12,45) scale 1.9; in another image, a keypoint has location (67,24) scake 2.8. I check both of the images and confirm May 9 comment Where can I get S. Heymann's GPU Implementation of SIFT Algorithm?I sent an email 3 days ago, no reply... May 7 asked Where can I get S. Heymann's GPU Implementation of SIFT Algorithm? Apr 24 comment How does Lowe compute the “repeatability” of his SIFT Algorithm?I understand equation (1), what i do not understand is that the tolerance "σ pixels" is for all of the keypoints, which means the keypoint with a large scale(3σ), will have the same tolerance with the keypoint with a small scale(1.5σ), which is not fair, I think. Can you give me a hint? Apr 24 comment How does Lowe compute the “repeatability” of his SIFT Algorithm?"the same location" is defined as being within σ pixels in the x and y directions, where "σ is the scale of the keypoint (deﬁned from equation (1) as the standard deviation of the smallest Gaussian used in the difference-of-Gaussian function)". So the keypoint with a large scale, say, 3 σ, will have the same tolerance with the keypoint with a small scale, say 1.5 σ? Apr 24 comment How does Lowe compute the “repeatability” of his SIFT Algorithm?link added. thx Apr 24 awarded Editor Apr 24 revised How does Lowe compute the “repeatability” of his SIFT Algorithm?deleted 5 characters in body Apr 24 asked How does Lowe compute the “repeatability” of his SIFT Algorithm? Apr 20 awarded Tumbleweed Apr 16 awarded Editor Feb 24 comment How to rotate orientation in "Fast Approximated SIFT"?I tried linear interpolation with matlab before, the result histogram is not close to the real histogram. What is the method the authors proposed? If the orientation of the keypoint is PI/6, they just use the orignial histogram(2 4 5 3 6 8 7) or the histogram with orientation PI/4(4 5 3 6 8 7 1 2) to approximate the real histogram? Wouldn't that be too imprecise?