# HG changeset patch
# User Tuomo Valkonen <tuomov@iki.fi>
# Date 1576695396 -7200
# Node ID 4403f044581474336d8042c674c55162887a3cae
# Parent  a9ea98043eb9f4232e337a318aaebe18374bb755
Add gaussian distr to avoid hevy ImageFiltering dependencies.

diff -r a9ea98043eb9 -r 4403f0445814 src/ImFilter.jl
--- a/src/ImFilter.jl	Mon Dec 16 13:37:08 2019 +0200
+++ b/src/ImFilter.jl	Wed Dec 18 20:56:36 2019 +0200
@@ -13,7 +13,8 @@
 # Exports
 ##########
 
-export simple_imfilter
+export simple_imfilter,
+       gaussian
 
 ##############
 # The routine
@@ -54,5 +55,20 @@
     return res
 end
 
+######################################################
+# Distributions. Just to avoid the long load times of
+# ImageFiltering and heavy dependencies on FFTW etc.
+######################################################
+
+function gaussian(σ, n)
+    @assert(all(isodd.(n)))
+    a=convert.(Integer, @. (n-1)/2)
+    g=OffsetArray{Float64}(undef, [-m:m for m in a]...);
+    for i in CartesianIndices(g)
+        g[i]=exp(-sum(Tuple(i).^2 ./ (2 .* σ.^2)))
+    end
+    g./=sum(g)
+end
+
 end # Module