Darknet: Different anchors mask between yolov3.cfg and csresnext50-panet-spp.cfg

[bill97385]

Hi all

I found there are some small different setting masks

from yolov3.cfg

start at 6,7,8
[yolo]
mask = 6,7,8

from csresnext50-panet-spp.cfg

start at 0,1,2
[yolo]
mask = 0,1,2

is that mean csresnext50 should start from small anchors or just some mistake???

[WongKinYiu]

It just because yolov3 use FPN-like model (top-down), and csresnext50-panet-spp use PAN-like model (top-down -> bottom-up).

• yolov3:
  (start backbone) -> 1x -> 2x -> 4x -> 8x -> 16x -> 32x
  -> (start top-down) -> 32x -> (predict 6,7,8) -> 16x -> (predict 3,4,5) -> 8x -> (predict 0,1,2)

• csresnext50-panet-spp:
  (start backbone) -> 1x -> 2x -> 4x -> 8x -> 16x -> 32x
  -> (start top-down) -> 32x -> 16x -> 8x
  -> (start bottom-up) -> 8x -> (predict 0,1,2) -> 16x -> (predict 3,4,5) -> 32x -> (predict 6,7,8)

[bill97385]

Got it!!

Many thanks