Plotting a sequence of images as a gif

New to Julia
21

Well, I guess this is an attractive feature request :-).
For me, I think it is easy enough to automate this by wrapping APNG Assembler with some OS level calls.

22

I tried apng assembler but I have been a bit disappointed : it was much longer to run than saving to gif ( about a minute vs a few seconds) and the resulting png was twice bigger than the gif without an obvious quality enhancementā€¦

23

If your color palette is narrow they should be similar quality wise. Yet APNG should have better compression. As far as I can remember to the least.

24

Iā€™m trying to create a .gif from several images too. The save function doesnā€™t work for my array although I feel like this is functionally similar to the example. Any recommendations?

using FileIO, ImageIO, Colors, FixedPointNumbers, Images

folder = 
A = Array{Array{RGB{Normed{UInt8,8}},2},1}()

for i in 1:200
    img_path = "tmp/"*string(i)*".png"
    img = load(img_path)
    push!(A,img)
end

save("test.gif", A)

ā”Œ Warning: Mapping to the storage type failed; perhaps your data had out-of-range values?
ā”‚ Try `map(clamp01nan, img)` to clamp values to a valid range.
ā”” @ ImageMagick ImageMagick\0LwpT\src\ImageMagick.jl:180
Error encountered while saving "test.gif".

Fatal error:
ERROR: LoadError: MethodError: no method matching mapIM(::Array{RGB{Normed{UInt8,8}},2})
Closest candidates are:
  mapIM(::Bool) at \ImageMagick\0LwpT\src\ImageMagick.jl:264
  mapIM(::UInt16) \ImageMagick\0LwpT\src\ImageMagick.jl:262
  mapIM(::UInt32) \ImageMagick\0LwpT\src\ImageMagick.jl:263
  ...
25

It should be a 3d array (HWT, T = time), not a vector-of-matrices.

26

Yes. Thank you.

A = cat(A, load(img_path), dims=3)
27

Actually, if you zoom and open on another tab, you can see it move once.

28

Thanks for this tip! I think using this format just solved a big problem Iā€™m having with regular GIFs and the headaches that come along with indexed colors.

29

This is not working for me:

using FileIO, ImageIO, Colors, FixedPointNumbers, Images

folder = "video"
A = Array{Array{RGB{Normed{UInt8,8}},2},1}()

for j in 0:66
    global A
    local img
    img_path = folder*"/"*"img-"*lpad(j,4,"0")*".png"
    img=load(img_path)
    A = cat(A, img, dims=3)
end

save("video/Tether.gif", A)

Error message:

julia> include("src/export_gif.jl")
ERROR: LoadError: DimensionMismatch: mismatch in dimension 1 (expected 0 got 480)
Stacktrace:
  [1] _cs
    @ Base ./abstractarray.jl:1782 [inlined]
  [2] _cshp
    @ Base ./abstractarray.jl:1778 [inlined]
  [3] _cat_size_shape(::Tuple{Bool, Bool, Bool}, ::Tuple{Int64, Int64, Int64}, ::Matrix{RGBA{N0f8}})
    @ Base ./abstractarray.jl:1758
  [4] cat_size_shape
    @ ./abstractarray.jl:1756 [inlined]
  [5] _cat_t
    @ ./abstractarray.jl:1797 [inlined]
  [6] _cat(::Int64, ::Vector{Matrix{RGB{N0f8}}}, ::Matrix{RGBA{N0f8}})
    @ Base ./abstractarray.jl:1793
  [7] #cat#159
    @ Base ./abstractarray.jl:1990 [inlined]
  [8] top-level scope
    @ ~/repos/Tethers.jl/src/export_gif.jl:11
  [9] include(fname::String)
    @ Base.MainInclude ./client.jl:489
 [10] top-level scope
    @ REPL[3]:1
in expression starting at /home/ufechner/repos/Tethers.jl/src/export_gif.jl:6

What am I doing wrong?

30

OK, this works:

using FileIO, ImageIO, Colors, FixedPointNumbers, Images

folder = "video"
A = Array{Array{RGB{Normed{UInt8,8}},2},1}()

for j in 0:66
    global A
    local img
    img_path = folder*"/"*"img-"*lpad(j,4,"0")*".png"
    img=load(img_path)
    if j==0
        A=img
    else
        A = cat(A, img, dims=3)
    end
end

save(folder * "/Tether.gif", A)
31

This snippet (which I have used hundreds of times, so useful!) seems to have stopped working.

It now gives a message to the effect of

===========================================
UndefVarError: `libwand` not defined
===========================================

Fatal error:
ERROR: BoundsError: attempt to access 4Ɨ32Ɨ32Ɨ5 reinterpret(UInt8, ::Array{N0f8,4}) at index [1:4, 1:32, 1]
Stacktrace:
  [1] throw_boundserror(A::Base.ReinterpretArray{ā€¦}, I::Tuple{ā€¦})
    @ Base ./abstractarray.jl:734
  [2] checkbounds
    @ ./abstractarray.jl:699 [inlined]
  [3] _getindex
    @ ./multidimensional.jl:888 [inlined]
  [4] getindex
    @ ./abstractarray.jl:1288 [inlined]
  [5] save_(f::FileIO.File{ā€¦}, img::Array{ā€¦}; permute_horizontal::Bool, mapi::typeof(identity))
    @ QuartzImageIO ~/.julia/packages/QuartzImageIO/4Fkqk/src/QuartzImageIO.jl:310

Is this a QuartzImageIO.jl, ImageMagick.jl, or FileIO.jl issue, do we think?

32

This issue seems relevant to libwand error.

33

Itā€™s both ImageMagick (the source of the libwand error) and QuartzImageIO (the source of the BoundsError). Iā€™m guessing the ImageMagick_jll version may have changed, you could try pinning it perhaps.

Fundamentally, ImageMagick has been a never-ending source of trouble. You might try GitHub - JuliaIO/GIFImages.jl: Provides Gif support in Julia using LibGif and see if that works better.

34

Is there a _jll for APNG Assembler?