Negative mining in TripletSelectLayer

[PramuPerera]

Hello,

When selecting the negative triplet, right now, you are picking the sample furthest away from the anchor.

for i in range(self.triplet):
negative_feature = bottom[0].data[i+self.triplet2]
a_n = archor_feature - negative_feature
an = np.dot(a_n,a_n)
ans[i+self.triplet2] = an
ans = sorted(ans.items(), key = lambda d: d[1], reverse = True)

top_negative.append(bottom[0].data[ans[i][0]])

If we are mining the hardest negative sample, shouldn,'t we consider the closest negative sample to the anchor? Correct me if I'm wrong. Thanks!

[luhaofang]

Hi, you are not wrong, the select method is used to smooth the gradient, much depends on your dataset.