From 460a2b75c9042f7a1e80ccae63c585f013f90d9a Mon Sep 17 00:00:00 2001
From: Johnny Chen <johnnychen94@hotmail.com>
Date: Wed, 4 May 2022 16:23:08 +0800
Subject: [PATCH] add IndirectArrays (#48)

---
 Project.toml     |  4 +++-
 src/ImageIO.jl   |  4 +++-
 test/runtests.jl | 15 +++++++++++++--
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/Project.toml b/Project.toml
index 844a05a..adfc4be 100644
--- a/Project.toml
+++ b/Project.toml
@@ -5,6 +5,7 @@ version = "0.6.1"
 
 [deps]
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"
+IndirectArrays = "9b13fd28-a010-5f03-acff-a1bbcff69959"
 JpegTurbo = "b835a17e-a41a-41e7-81f0-2f016b05efe0"
 Netpbm = "f09324ee-3d7c-5217-9330-fc30815ba969"
 OpenEXR = "52e1d378-f018-4a11-a4be-720524705ac7"
@@ -16,8 +17,9 @@ UUIDs = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
 
 [compat]
 FileIO = "1.2"
-JpegTurbo = "0.1"
+IndirectArrays = "0.5, 1"
 ImageCore = "0.8.1, 0.9"
+JpegTurbo = "0.1"
 Netpbm = "1.0"
 OpenEXR = "0.3"
 PNGFiles = "0.3"
diff --git a/src/ImageIO.jl b/src/ImageIO.jl
index 55e90a2..503dece 100644
--- a/src/ImageIO.jl
+++ b/src/ImageIO.jl
@@ -3,6 +3,8 @@ module ImageIO
 using UUIDs
 using FileIO: File, DataFormat, Stream, stream, Formatted
 
+import IndirectArrays: IndirectArray
+
 const idSixel = Base.PkgId(UUID("45858cf5-a6b0-47a3-bbea-62219f50df47"), "Sixel")
 const idNetpbm = Base.PkgId(UUID("f09324ee-3d7c-5217-9330-fc30815ba969"), "Netpbm")
 const idPNGFiles = Base.PkgId(UUID("f57f5aa1-a3ce-4bc8-8ab9-96f992907883"), "PNGFiles")
@@ -17,7 +19,6 @@ const idJpegTurbo = Base.PkgId(UUID("b835a17e-a41a-41e7-81f0-2f016b05efe0"), "Jp
 for FMT in (
     :PBMBinary, :PGMBinary, :PPMBinary, :PBMText, :PGMText, :PPMText,
     :TIFF,
-    :PNG,
     :EXR,
     :QOI,
     :SIXEL,
@@ -26,6 +27,7 @@ for FMT in (
     @eval canonical_type(::DataFormat{$(Expr(:quote, FMT))}, ::AbstractArray{T, N}) where {T,N} =
         Array{T,N}
 end
+@inline canonical_type(::DataFormat{:PNG}, ::AbstractArray{T, N}) where {T,N} = Union{Array{T,N}, IndirectArray{T,N}}
 @inline canonical_type(::Formatted{T}, data) where T = canonical_type(T(), data)
 
 function enforce_canonical_type(f, data)
diff --git a/test/runtests.jl b/test/runtests.jl
index 771d628..ab2d2f7 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -2,6 +2,7 @@ using Test
 using ImageIO
 using FileIO: File, DataFormat, Stream, @format_str
 using ImageCore: N0f8, RGB, Gray, RGBA, GrayA, n0f8
+using IndirectArrays
 using ImageQualityIndexes
 
 tmpdir = mktempdir()
@@ -30,7 +31,7 @@ Threads.nthreads() <= 1 && @info "Threads.nthreads() = $(Threads.nthreads()), mu
                 else
                     @test img == img_saveload
                 end
-                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
+                @test img_saveload isa Array
                 img_saveload = ImageIO.load(f; gamma=1.0)
                 if typ == UInt8
                     @test all(img .== reinterpret(UInt8, img_saveload))
@@ -45,7 +46,7 @@ Threads.nthreads() <= 1 && @info "Threads.nthreads() = $(Threads.nthreads()), mu
                 else
                     @test img == img_saveload
                 end
-                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
+                @test img_saveload isa Array
 
                 ImageIO.save(f, img; compression_level=1)
                 img_saveload = ImageIO.load(f)
@@ -56,6 +57,16 @@ Threads.nthreads() <= 1 && @info "Threads.nthreads() = $(Threads.nthreads()), mu
                 end
             end
         end
+
+        @testset "indexed image" begin
+            f = File{DataFormat{:PNG}}(joinpath(tmpdir, "test_fpath.png"))
+            img = IndirectArray(rand(1:5, 4, 4), rand(RGB{N0f8}, 5))
+            ImageIO.save(f, img)
+            img_saveload = ImageIO.load(f)
+
+            @test img == img_saveload
+            @test img isa IndirectArray
+        end
     end
 
     @testset "Portable bitmap" begin