scans location recover in function about generateBoundingBox() ?

[Wenchao-Du]

i have been reimplementing this work presently, but i have a problem about the "P-net"，we need recover original scans location from output feature maps, but why the stride was set 2, i could not understand it clearly, the code is follow:
stride=2; boundingbox=[fix((stride*(boundingbox-1)+1)/scale) fix((stride*(boundingbox-1)+cellsize-1+1)/scale) score reg];
could you explain it simplely? thanks.

[ZhiqiJiang]

Because P-net only have one pooling layer, namely shifting one step in output feature map is equal to shifting two step in input layer.