arrow_image_dataset

arrow_image_dataset.jl

using TestImages, Images, Arrow, ImageInTerminal

# img = testimage("cameraman")
# img = testimage("airplaneF16")
img = testimage("autumn_leaves")

_arrowname(::Type{Gray}) = Symbol("JuliaLang.Gray")
_arrowname(::Type{RGB}) = Symbol("JuliaLang.RGB")
_arrowname(::Type{RGBA}) = Symbol("JuliaLang.RGBA")

const str2type = Dict{String, Type}(
                    "N0f8" => N0f8,
                    "N0f16" => N0f16,
                )

ArrowTypes.arrowname(::Type{Gray{T}}) where {T} = _arrowname(Gray)
ArrowTypes.arrowname(::Type{RGB{T}}) where {T} = _arrowname(RGB)
ArrowTypes.arrowname(::Type{RGBA{T}}) where {T} = _arrowname(RGBA)

ArrowTypes.arrowmetadata(::Type{Gray{T}}) where {T} =  string(T)
ArrowTypes.arrowmetadata(::Type{RGB{T}}) where {T} =  string(T)
ArrowTypes.arrowmetadata(::Type{RGBA{T}}) where {T} =  string(T)

function ArrowTypes.JuliaType(::Val{_arrowname(Gray)}, ::Type{NamedTuple{names, types}}, meta) where {names, types}
    # @show meta names types
    T = str2type[meta]
    return Gray{T}
end
function ArrowTypes.JuliaType(::Val{_arrowname(RGB)}, ::Type{NamedTuple{names, types}}, meta) where {names, types}
    # @show meta names types
    T = str2type[meta]
    return RGB{T}
end
function ArrowTypes.JuliaType(::Val{_arrowname(RGBA)}, ::Type{NamedTuple{names, types}}, meta) where {names, types}
    # @show meta names types
    T = str2type[meta]
    return RGBA{T}
end

function ArrowTypes.fromarrow(::Type{Gray{T}}, x::NamedTuple) where {T}
    return Gray{T}(reinterpret(T, x.i))
end
function ArrowTypes.fromarrow(::Type{RGB{T}}, x::NamedTuple) where {T}
    return RGB{T}(reinterpret(T, x[1].i), reinterpret(T, x[2].i), reinterpret(T, x[3].i))
end
function ArrowTypes.fromarrow(::Type{RGBA{T}}, x::NamedTuple...) where {T}
    return RGBA{T}(reinterpret(T, x[1].i), reinterpret(T, x[2].i), reinterpret(T, x[3].i), reinterpret(T, x[4].i))
end

function write_arrowtable(file::AbstractString, table::NamedTuple; store_size=true)
    extracols = []
    if store_size
        for (k, v) in pairs(table)
            @assert v isa AbstractVector
            if eltype(v) <: AbstractArray
                if !(eltype(v) <: AbstractVector)
                    size_key = Symbol(k, "_size")
                    push!(extracols, size_key => size.(v))
                end
            end
        end
    end
    return Arrow.write(file, (; table..., extracols...))
end

write_arrowtable("testarrow.arrow", (x=[img, img], y=[1, 2]))

read_arrowtable(file::AbstractString) = Arrow.Table(file)

a = read_arrowtable("testarrow.arrow")

a.x

reshape(a.x, size(img))