julia - 如何从图像中提取RGB值并计算其输出？

Question

我有一个函数，可以从图像中获取 RGB 值并计算每个像素的平均值，我该如何解决这个问题？

function RGB2G_mean(img::Matrix{RGB{T}}) where T<:Fractional
    # get RGB-values from img
     # R,G,B=...

     output =
    return Gray.(output)
end

Answer 1

julia> using Colors, ColorVectorSpace, FixedPointNumbers, Statistics

julia> a = rand(RGB{N0f8}, 4)
4-element Array{RGB{N0f8},1} with eltype RGB{N0f8}:
 RGB{N0f8}(0.588,0.459,0.529)
 RGB{N0f8}(0.592,0.247,0.408)
 RGB{N0f8}(0.31,0.18,0.396)
 RGB{N0f8}(0.235,1.0,0.675)

julia> mean(a)
RGB{Float64}(0.43137254901960786,0.4715686274509804,0.5019607843137255)

为了解决评论中 BatWannaBe 的担忧，是的，mean 可以防止溢出。