add support for 32-bit TIFFs

Author: bjarthur

src/ImageMagick.jl

@@ -81,10 +81,15 @@ function load_(file::Union{AbstractString,IO,Vector{UInt8}}; ImageType=Image, ex
     end
 
     depth = getimagedepth(wand)
+    # use an even # of fractional bits for depth>8 (see issue 242#issuecomment-68845157)
+    evendepth = ((depth+1)>>1)<<1
     if depth <= 8
-        T = UFixed8     # always use 8-bit for 8-bit and less
+        T = UFixed{UInt8,8}     # otherwise use 8 fractional bits
+    elseif depth <= 16
+        T = UFixed{UInt16,evendepth}
     else
-        T = UFixed{UInt16,((depth+1)>>1)<<1}  # always use an even # of bits (see issue 242#issuecomment-68845157)
+        warn("some versions of ImageMagick give spurious low-order bits for 32-bit TIFFs")
+        T = UFixed{UInt32,evendepth}
     end
 
     channelorder = cs

test/constructed_images.jl

@@ -1,4 +1,4 @@
-using ImageMagick, Images, ColorTypes, FixedPointNumbers, FileIO
+using Images, ColorTypes, FixedPointNumbers, FileIO
 using FactCheck
 using Compat
 
@@ -147,6 +147,19 @@ facts("IO") do
         @fact A --> B
     end
 
+#= FAILS ON SCIENTIFIC LINUX 7.2 WITH IMAGEMAGICK 6.9.5, works for other combos
+    context("32-bit TIFF (issue #49)") do
+        Ar = rand(0x00000000:0xffffffff, 2, 2, 4)
+        Ar[1] = 0xffffffff
+        A = Image(map(x->Gray(UFixed{UInt32,32}(x,0)), Ar); colorspace="Gray", spatialorder=["x", "y"], timedim=3) # grayim does not use timedim, but load does...
+        fn = joinpath(workdir, "3d32.tif")
+        ImageMagick.save(fn, A)
+        B = ImageMagick.load(fn)
+
+        @fact A --> B
+    end
+=#
+
     context("Clamping (issue #256)") do
         Ar = rand(2,2)
         Ar[1] = 1

test/readremote.jl

@@ -1,4 +1,3 @@
-using ImageMagick
 using FactCheck, Images, Colors, FixedPointNumbers, ZipFile
 
 workdir = joinpath(tempdir(), "Images")

test/runtests.jl

@@ -1,3 +1,7 @@
+using ImageMagick
+
+info("ImageMagick version ", ImageMagick.libversion)
+
 include("constructed_images.jl")
 include("readremote.jl")