Use label_components with non-Array output

gistfile1.jl

type Naive_Sparse_3{T} <: AbstractArray{T,3}
    size::(Int,Int,Int)
    vals::Dict{Int,T}
end 
function getindex(A::Naive_Sparse_3,i::Int)
    A.vals[i]
end 
function getindex(A::Naive_Sparse_3,i1::Int,i2::Int,i3::Int)
    i=((i3-1)*A.size[1]+(i2-1))*A.size[2]+i1
    getindex(A,i)
end 
function setindex!(A::Naive_Sparse_3,x,i::Int)
    A.vals[i]=x
end 
function setindex!(A::Naive_Sparse_3,x,i1::Int,i2::Int,i3::Int)
    i=((i3-1)*A.size[1]+(i2-1))*A.size[2]+i1
    setindex!(A,x,i)
end 
Base.size(A::Naive_Sparse_3)=A.size

label_components2(A, connectivity = 1:ndims(A), bkg = 0) = label_components!(Naive_Sparse_3(size(A),Dict{Int,Int}()), A, connectivity, bkg)

using Images
x=rand(100,100,1000);
x2=x.>0.95;

label_components(x2);
label_components2(x2);