Merge pull request #62 from bjarthur/bja/typeminmax

added typemin/max for AbstractGray

Author: timholy

src/ColorVectorSpace.jl

@@ -9,7 +9,7 @@ import Base: ==, +, -, *, /, .+, .-, .*, ./, ^, .^, <, ~
 import Base: abs, abs2, clamp, convert, copy, div, eps, isfinite, isinf,
     isnan, isless, length, mapreduce, norm, one, promote_array_type,
     promote_op, promote_rule, zero, trunc, floor, round, ceil, bswap,
-    mod, rem, atan2, hypot, max, min, varm, real
+    mod, rem, atan2, hypot, max, min, varm, real, typemin, typemax
 
 export nan
 
@@ -460,4 +460,6 @@ histrange{T}(v::AbstractArray{Gray{T}}, n::Integer) = histrange(convert(Array{Fl
 promote_array_type{T<:Real,C<:MathTypes}(F, ::Type{T}, ::Type{C}) = base_colorant_type(C){Base.promote_array_type(F, T, eltype(C))}
 promote_rule{T<:Real,C<:AbstractGray}(::Type{T}, ::Type{C}) = promote_type(T, eltype(C))
 
+typemin{T<:ColorTypes.AbstractGray}(::Union{T,Type{T}}) = T(typemin(eltype(T)))
+typemax{T<:ColorTypes.AbstractGray}(::Union{T,Type{T}}) = T(typemax(eltype(T)))
 end

test/runtests.jl

@@ -340,7 +340,18 @@ end
         @test isapprox(dotc(xc, yc) , dotc(convert(Gray, xc), convert(Gray, yc)), atol=1e-6)
         @test dotc(RGB(1,0,0), RGB(0,1,1)) == 0
     end
-end
 
+    @testset "typemin/max" begin
+        for T in (Normed{UInt8,8}, Normed{UInt8,6}, Normed{UInt16,16}, Normed{UInt16,14}, Float32, Float64)
+            @test typemin(Gray{T}) === Gray{T}(typemin(T))
+            @test typemax(Gray{T}) === Gray{T}(typemax(T))
+            @test typemin(Gray{T}(0.5)) === Gray{T}(typemin(T))
+            @test typemax(Gray{T}(0.5)) === Gray{T}(typemax(T))
+            A = maximum(Gray{T}.([1 0 0; 0 1 0]), 1)  # see PR#44 discussion
+            @test isa(A, Matrix{Gray{T}})
+            @test size(A) == (1,3)
+        end
+    end
+end
 
 end