diff --git a/.gitignore b/.gitignore
index 9146a07..c7c7790 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
+# Platform- and user- specific contents and configurations
 .DS_Store
+.vscode
 
 # Files generated by invoking Julia with --code-coverage
 *.jl.cov
diff --git a/src/ImageIO.jl b/src/ImageIO.jl
index 2f1af0a..31ade9f 100644
--- a/src/ImageIO.jl
+++ b/src/ImageIO.jl
@@ -1,12 +1,25 @@
 module ImageIO
 
 using UUIDs
-using FileIO: File, DataFormat, Stream, stream
+using FileIO: File, DataFormat, Stream, stream, Formatted
 
 const idNetpbm = Base.PkgId(UUID("f09324ee-3d7c-5217-9330-fc30815ba969"), "Netpbm")
 const idPNGFiles = Base.PkgId(UUID("f57f5aa1-a3ce-4bc8-8ab9-96f992907883"), "PNGFiles")
 const idTiffImages = Base.PkgId(UUID("731e570b-9d59-4bfa-96dc-6df516fadf69"), "TiffImages")
 
+# Enforce a type conversion to be backend independent (issue #25)
+# Note: If the backend does not provide efficient `convert` implementation,
+#       there will be an extra memeory allocation and thus hurt the performance.
+for FMT in (
+    :PBMBinary, :PGMBinary, :PPMBinary, :PBMText, :PGMText, :PPMText,
+    :TIFF,
+    :PNG,
+)
+    @eval canonical_type(::DataFormat{$(Expr(:quote, FMT))}, ::AbstractArray{T, N}) where {T,N} =
+        Array{T,N}
+end
+@inline canonical_type(::Formatted{T}, data) where T = canonical_type(T(), data)
+
 ## PNGs
 
 const load_locker = Threads.ReentrantLock()
@@ -19,10 +32,12 @@ function checked_import(pkgid)
 end
 
 function load(f::File{DataFormat{:PNG}}; kwargs...)
-    return Base.invokelatest(checked_import(idPNGFiles).load, f.filename, kwargs...)
+    data = Base.invokelatest(checked_import(idPNGFiles).load, f.filename, kwargs...)
+    return convert(canonical_type(f, data), data)
 end
 function load(s::Stream{DataFormat{:PNG}}; kwargs...)
-    return Base.invokelatest(checked_import(idPNGFiles).load, stream(s), kwargs...)
+    data = Base.invokelatest(checked_import(idPNGFiles).load, stream(s), kwargs...)
+    return convert(canonical_type(s, data), data)
 end
 
 function save(f::File{DataFormat{:PNG}}, image::S; kwargs...) where {T, S<:Union{AbstractMatrix, AbstractArray{T,3}}}
@@ -44,11 +59,13 @@ end
 for NETPBMFORMAT in (:PBMBinary, :PGMBinary, :PPMBinary, :PBMText, :PGMText, :PPMText)
     @eval begin
         function load(f::File{DataFormat{$(Expr(:quote,NETPBMFORMAT))}})
-            return Base.invokelatest(checked_import(idNetpbm).load, f)
+            data = Base.invokelatest(checked_import(idNetpbm).load, f)
+            return convert(canonical_type(f, data), data)
         end
 
         function load(s::Stream{DataFormat{$(Expr(:quote,NETPBMFORMAT))}})
-            return Base.invokelatest(checked_import(idNetpbm).load, s)
+            data = Base.invokelatest(checked_import(idNetpbm).load, s)
+            return convert(canonical_type(s, data), data)
         end
 
         function save(f::File{DataFormat{$(Expr(:quote,NETPBMFORMAT))}}, image::S; kwargs...) where {S<:AbstractMatrix}
@@ -64,10 +81,12 @@ end
 ## TIFFs
 
 function load(f::File{DataFormat{:TIFF}}; kwargs...)
-    return Base.invokelatest(checked_import(idTiffImages).load, f.filename, kwargs...)
+    data = Base.invokelatest(checked_import(idTiffImages).load, f.filename, kwargs...)
+    return convert(canonical_type(f, data), data)
 end
 function load(s::Stream{DataFormat{:TIFF}}; kwargs...)
-    return Base.invokelatest(checked_import(idTiffImages).load, stream(s), kwargs...)
+    data = Base.invokelatest(checked_import(idTiffImages).load, stream(s), kwargs...)
+    return convert(canonical_type(s, data), data)
 end
 
 function save(f::File{DataFormat{:TIFF}}, image::S) where {T, S<:Union{AbstractMatrix, AbstractArray{T,3}}}
diff --git a/test/runtests.jl b/test/runtests.jl
index ffa8570..c9b5c64 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -29,14 +29,16 @@ 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)
 
-                open(io->ImageIO.save(Stream(format"PNG", io), img, permute_horizontal=false), joinpath(tmpdir, "test_io.png"), "w")
-                img_saveload = open(io->ImageIO.load(Stream(format"PNG", io)), joinpath(tmpdir, "test_io.png"))
+                open(io->ImageIO.save(Stream{format"PNG"}(io), img, permute_horizontal=false), joinpath(tmpdir, "test_io.png"), "w")
+                img_saveload = open(io->ImageIO.load(Stream{format"PNG"}(io)), joinpath(tmpdir, "test_io.png"))
                 if typ == UInt8
                     @test all(img .== reinterpret(UInt8, img_saveload))
                 else
                     @test img == img_saveload
                 end
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
             end
         end
     end
@@ -49,10 +51,12 @@ Threads.nthreads() <= 1 && @info "Threads.nthreads() = $(Threads.nthreads()), mu
                 ImageIO.save(f, img)
                 img_saveload = ImageIO.load(f)
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
 
-                open(io->ImageIO.save(Stream(fmt, io), img), joinpath(tmpdir, "test_io.pbm"), "w")
-                img_saveload = open(io->ImageIO.load(Stream(fmt, io)), joinpath(tmpdir, "test_io.pbm"))
+                open(io->ImageIO.save(Stream{fmt}(io), img), joinpath(tmpdir, "test_io.pbm"), "w")
+                img_saveload = open(io->ImageIO.load(Stream{fmt}(io)), joinpath(tmpdir, "test_io.pbm"))
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
             end
         end
 
@@ -63,10 +67,12 @@ Threads.nthreads() <= 1 && @info "Threads.nthreads() = $(Threads.nthreads()), mu
                 ImageIO.save(f, img)
                 img_saveload = ImageIO.load(f)
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
 
-                open(io->ImageIO.save(Stream(fmt, io), img), joinpath(tmpdir, "test_io.pgm"), "w")
-                img_saveload = open(io->ImageIO.load(Stream(fmt, io)), joinpath(tmpdir, "test_io.pgm"))
+                open(io->ImageIO.save(Stream{fmt}(io), img), joinpath(tmpdir, "test_io.pgm"), "w")
+                img_saveload = open(io->ImageIO.load(Stream{fmt}(io)), joinpath(tmpdir, "test_io.pgm"))
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
             end
         end
 
@@ -77,10 +83,12 @@ Threads.nthreads() <= 1 && @info "Threads.nthreads() = $(Threads.nthreads()), mu
                 ImageIO.save(f, img)
                 img_saveload = ImageIO.load(f)
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
 
-                open(io->ImageIO.save(Stream(fmt, io), img), joinpath(tmpdir, "test_io.ppm"), "w")
-                img_saveload = open(io->ImageIO.load(Stream(fmt, io)), joinpath(tmpdir, "test_io.ppm"))
+                open(io->ImageIO.save(Stream{fmt}(io), img), joinpath(tmpdir, "test_io.ppm"), "w")
+                img_saveload = open(io->ImageIO.load(Stream{fmt}(io)), joinpath(tmpdir, "test_io.ppm"))
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
             end
         end
     end
@@ -93,10 +101,12 @@ Threads.nthreads() <= 1 && @info "Threads.nthreads() = $(Threads.nthreads()), mu
                 ImageIO.save(f, img)
                 img_saveload = ImageIO.load(f)
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
 
-                open(io->ImageIO.save(Stream(format"TIFF", io), img), joinpath(tmpdir, "test_io.tiff"), "w")
-                img_saveload = open(io->ImageIO.load(Stream(format"TIFF", io)), joinpath(tmpdir, "test_io.tiff"))
+                open(io->ImageIO.save(Stream{format"TIFF"}(io), img), joinpath(tmpdir, "test_io.tiff"), "w")
+                img_saveload = open(io->ImageIO.load(Stream{format"TIFF"}(io)), joinpath(tmpdir, "test_io.tiff"))
                 @test img == img_saveload
+                @test typeof(img_saveload) == ImageIO.canonical_type(f, img_saveload)
             end
         end
     end