More round-trip tests. All pass.

Author: twadleigh

test/runtests.jl

@@ -1,5 +1,22 @@
 using Test, OpenEXR, FileIO, Colors, FixedPointNumbers
 
+# helpers for testing channelwise bit-depth truncation
+function channelwise_max_diff(a::RGBA, b::RGBA)
+    max(abs(a.r - b.r), abs(a.g - b.g), abs(a.b - b.b), abs(a.alpha - b.alpha))
+end
+
+function channelwise_max_diff(a::RGB, b::RGB)
+    max(abs(a.r - b.r), abs(a.g - b.g), abs(a.b - b.b))
+end
+
+function channelwise_max_diff(a::GrayA, b::GrayA)
+    max(abs(a.val - b.val), abs(a.alpha - b.alpha))
+end
+
+function channelwise_max_diff(a::Gray, b::Gray)
+    abs(a.val - b.val)
+end
+
 @testset "RoundTrip" begin
 
     @testset "Identical" begin
@@ -31,7 +48,7 @@ using Test, OpenEXR, FileIO, Colors, FixedPointNumbers
                 loaded_img = OpenEXR.load(fn)
                 @test typeof(loaded_img) === Array{load_type,2}
                 converted_img = (c -> convert(save_type, c)).(loaded_img)
-                @test converted_img == loaded_img
+                @test converted_img == img
             finally
                 rm(fn.filename)
             end
@@ -41,7 +58,6 @@ using Test, OpenEXR, FileIO, Colors, FixedPointNumbers
     @testset "Lossy with type conversion" begin
 
         @testset "Bit depth truncation" begin
-
             for (save_type, load_type) in (
                 (RGBA{Float32}, RGBA{Float16}),
                 (RGB{Float32}, RGB{Float16}),
@@ -53,9 +69,35 @@ using Test, OpenEXR, FileIO, Colors, FixedPointNumbers
                 OpenEXR.save(fn, img)
                 try
                     loaded_img = OpenEXR.load(fn)
+
+                    # return type is as expected
                     @test typeof(loaded_img) === Array{load_type,2}
-                    diffs = map(colordiff, color.(img), color.(loaded_img))
-                    @test diffs ≈ zeros(size(diffs)) rtol = 1e-10
+
+                    # differences are bounded channelwise
+                    diffs = map(channelwise_max_diff, img, loaded_img)
+                    @test maximum(diffs) <= 2.5e-4
+                finally
+                    rm(fn.filename)
+                end
+            end
+        end
+
+        @testset "Colorspace conversion" begin
+            for save_type in
+                (HSV{Float16}, HSL{Float16}, Lab{Float16}, LCHab{Float16}, YIQ{Float16})
+                img = rand(save_type, 256, 512)
+                fn = File{DataFormat{:EXR}}(tempname())
+                OpenEXR.save(fn, img)
+                try
+                    loaded_img = OpenEXR.load(fn)
+
+                    # return type is as expected
+                    @test typeof(loaded_img) === Array{RGB{Float16},2}
+
+                    # differences are bounded channelwise
+                    converted_img = (c -> convert(RGB{Float16}, c)).(img)
+                    diffs = map(channelwise_max_diff, converted_img, loaded_img)
+                    @test maximum(diffs) <= 2.5e-4
                 finally
                     rm(fn.filename)
                 end