Encode Operation

Project.toml

@@ -10,6 +10,7 @@ ColorVectorSpace = "c3611d14-8923-5661-9e6a-0046d554d3a4"
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"
 FixedPointNumbers = "53c48c17-4a7d-5ca2-90c5-79b7896eea93"
 Giflib_jll = "59f7168a-df46-5410-90c8-f2779963d0ec"
+Noise = "81d43f40-5267-43b7-ae1c-8b967f377efa"
 libgifextra_jll = "d7c3d077-fdb7-5318-9663-3e6817e0e281"
 
 [compat]

src/GIFImages.jl

@@ -5,10 +5,15 @@ include("../lib/LibGifExtra.jl")
 
 using .LibGif
 using .LibGifExtra
+using ColorTypes
+using ColorVectorSpace
+using FixedPointNumbers
+using FileIO
+using Noise
 
 include("decode.jl")
+include("encode.jl")
 
-export gif_decode
-
+export gif_decode, gif_encode
 
 end # module

src/decode.jl

@@ -1,7 +1,3 @@
-using ColorTypes
-using ColorVectorSpace
-using FixedPointNumbers
-using FileIO
 
 """
     gif_decode(filepath::AbstractString; use_localpalette=false)

src/encode.jl

@@ -0,0 +1,53 @@
+
+function gif_encode(filepath::AbstractString, img::AbstractArray, numcolors::Int=256)
+    Error = Cint(0)
+    gifFile = LibGif.EGifOpenFileName(filepath,0, Ref(Error));
+    colors = []
+
+    if (gifFile == C_NULL)
+        println("EGifOpenFileName() failed - ");
+        return false;
+    end
+
+    # generation of a colormap
+    img = quantization(img, num)
+    append!(colors, unique(img))
+    mapping = Dict()
+    for (i,j) in enumerate(colors)
+        mapping[j] = UInt8(i)
+    end
+
+    # defining the global colormap
+    colors = map(x->LibGif.GifColorType(x.r,x.g,x.b), colors*255)
+    ColorMap = LibGif.GifMakeMapObject(num, colors)
+
+    # features of the file
+    gifFile.SWidth = size(img)[2];
+    gifFile.SHeight = size(img)[1];
+    gifFile.SColorResolution = 8;
+    gifFile.SBackGroundColor = 0;
+    gifFile.SColorMap =  ColorMap
+
+    # creating the new mapping
+    new = zeros(UInt8, size(img))
+    for (i,j) in enumerate(img)
+        new[i] = mapping[j]
+    end
+
+    # encoding
+    for i in 1:size(img)[3]
+        # flatten the image
+        pix = [new[:,:,i]'...]
+        pix1 = pointer(map(x-> LibGif.GifByteType(x), convert(Vector{UInt8}, pix)))
+
+        # saving a new image in giffile
+        desc = LibGif.GifImageDesc(0,0,size(img)[2],size(img)[1],0, C_NULL)
+        c = LibGif.SavedImage(desc, pix1, 0, C_NULL)
+        LibGif.GifMakeSavedImage(gifFile, Ref(c))
+    end
+
+    # writing and closing the file
+    if(LibGif.EGifSpew(gifFile)  == LibGif.GIF_ERROR)
+        error("Failed to write to file!")
+    end
+end