Kmeans thresholding of a grayscale image

graythresh_kmeans.jl

function graythresh_kmeans(img)
    # Note, without the type annotation, this is slow because
    # mean appears not to be type stable here
    thresh = mean(img)::Gray{Float32}
    
    while true
        lastthresh = thresh
        nplus = 0
        nminus = 0
        splus = zero(typeof(thresh))
        sminus = zero(typeof(thresh))
    
        for v in img
            if v > thresh
                splus += v
                nplus += 1
            else
                sminus += v
                nminus += 1
            end
        end
        thresh = (splus/nplus + sminus/nminus)/2
        if thresh == lastthresh
            return thresh
        end
    end    
end

@jwmerrill
Can I use this code in a MIT licensed project?

Thank you,
Kind regards,
Ken Bastiaensen (@Ken-B)

Yes, please feel free.