ImageQualityIndexes._average_pooling seems to be broken in v0.2.2

[J1MC83N]

julia> A = [i+j+0.0 for i in -2:2,j in -2:2]
5×5 Matrix{Float64}:
 -4.0  -3.0  -2.0  -1.0  0.0
 -3.0  -2.0  -1.0   0.0  1.0
 -2.0  -1.0   0.0   1.0  2.0
 -1.0   0.0   1.0   2.0  3.0
  0.0   1.0   2.0   3.0  4.0

julia> ImageQualityIndexes._average_pooling(A)
3×3 Matrix{Float64}:
 -1.0  1.0  1.0
  1.0  3.0  3.0
  1.0  3.0  3.0

From this example it seems to be shifted compared to what I would expect.