Indexing into 2nd highest peak might break

[cpaniaguam]

In final2020.m the second highest peak is selected, but what if there is no second highest peak?

IceFloeTracker.jl/src/find_ice_labels.jl

Lines 20 to 28 in 1daa9ec

	function find_reflectance_peaks(
	reflectance_channel::Union{__T__,Matrix{Float64}};
	possible_ice_threshold::Float64=Float64(75 / 255),
	)::Int64
	reflectance_channel[reflectance_channel .< possible_ice_threshold] .= 0 #75 / 255
	_, counts = ImageContrastAdjustment.build_histogram(reflectance_channel)
	locs, _ = Peaks.findmaxima(counts)
	sort!(locs; rev=true)
	return locs[2] # second greatest peak

In master.m this scenario is handled:

if size(peakLocs1,1)>2 && size(peakLocs2,1)>2 
        peak1=peakLocs1(2);
        peak2=peakLocs2(2);
        ice_b=find(tiles_ref1b>peak1);
        ice_c=find(tiles_ref1c>peak2);
        ice_labels = intersect(intersect(ice_a,ice_b),ice_c);
        nlabel=mode(double(tiles_new2(ice_labels)));
else
        nlabel=1;    
end

Essentially, it checks that more than 2 peaks were found and if that is not the case it makes nlabels equal to 1. It's not entirely clear to me why this needs to be the case but I thought about noting this as I prep the workflow that uses tiling for these purposes.

@tdivoll @danielmwatkins